Think of koji as a powerhouse fermenter. Koji naturally contains large quantities of enzymes such as amylase (a starch-metabolizing enzyme) and protease (a protein-metabolizing enzyme). These enzymes convert starch and protein in the raw material into fermentable sugars and amino acids. This process improves the flavor, taste, and bioactivities of fermented foods. It is the essential catalyst for miso, soy sauce, and high-enzyme beverages like sour amazake.

The Science of Biological Catalysis

We cultivate the fungus Aspergillus oryzae to produce enzymes. These enzymes act as biological catalysts that drive the actual “fermentation” (in the culinary sense of the word) later in the recipe. From a biological standpoint, most koji-driven food transformation is not technically fermentation, as the process is driven by secreted enzymes rather than the metabolic activity of bacteria or yeast. To successfully grow koji—the catalyst for this transformation—we must recreate its ideal natural environment: a tropical microclimate that is consistently warm and highly humid. Also, cooking the rice correctly is as important as setting up an incubation chamber - most of the failures I’ve seen were due to poorly cooked rice.

Necessary Equipment

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• Incubation Chamber: A 150–200 liter plastic storage container with a lid.

• Substrate Trays: Gastronorm (GN) tray (1/1 or 1/2 size).

• Steaming Set-up: Instant Pot, stove, or other dedicated rice steaming equipment.

• Temperature Control: Inkbird temperature controller (switches heat mat).

• Humidity Control: Inkbird humidity controller (switches humidifier).

• Heat Source: Waterproof heat mat.

• Humidity Source: Ultrasonic humidifier.

• Separators: Noncombustible objects, such as small clay bowls, to lift the tray.

• Airflow Support: A cooling rack that fits inside the GN tray.

• Liners: Clean cotton cloth, double the size of the GN tray.

• Inoculator: Fine mesh spice shaker.

• Monitoring: Digital probe thermometer (meat thermometer).

Technical Preparation: Spore Dispersal

Pure koji spores (tané-koji) are microscopic and difficult to distribute evenly across several kilograms of rice. To ensure a uniform “bloom,” you must disperse the spores in a carrier medium.

• Mix 1 part koji spores with 10 parts toasted rice flour.

• Keep pure spores in a sealed container in the refrigerator.

• Store the 1:10 dispersed mixture in a cool, dry place until use.

Setting up the Incubation Chamber

Setup the chamber to ensure safety and stability. Place the heat mat at the bottom of the container. Position the clay spacers on the mat and set the GN tray on top.

Install the humidifier inside the container. Ensure the mist output does not point directly at the rice tray or bounce off the lid onto the substrate. Fix the Inkbird sensors to the internal side wall. Keep all external plugs and sockets outside the container to prevent short circuits from high condensation levels.

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The Recipe: Standard Rice Koji

Ingredients

• Rice: Polished white rice (short or medium grain).

• Spores: Dispersed spore/flour mixture (1:10 ratio).

• Water: Filtered water for rinsing and soaking.

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In the pristine world of modern sake, where liquid is polished until it is as clear as glass, there exists a rowdier, more ancient ancestor: Doburoku. This is sake in its most primal state—unfiltered, thick, and fizzing with life. Often called “cloudy” or “chunky” sake, doburoku is the raw, rustic expression of fermentation.

Unlike the refined seishu found on store shelves, doburoku is a “living” beverage that blurs the line between food and drink. For centuries, this was the spirit of the Japanese countryside. While commercial sake involves a rigorous, three-step addition process, doburoku is defined by its elegant simplicity. It is often referred to as zenkoji-zukuri, a “one-step” fermentation where all ingredients are combined at once.

Today, a “Doburoku Renaissance” is underway, fueled by a global interest in fermentation and a desire to return to artisanal, living foods.

The Magic of Parallel Fermentation

The soul of doburoku lies in a unique biological dance known as Multiple Parallel Fermentation. In beer, starches are converted to sugar first and then fermented into alcohol in a separate stage. In the doburoku jar, these acts happen simultaneously:

• Koji (Aspergillus oryzae) enzymes break down rice starches into glucose.

• Lactic Acid Bacteria (LAB), naturally present on fresh koji rice, feed on that glucose. This inhibits the growth of pathogenic bacteria at the early stage of fermentation and imparts a refreshing acidity.

• Yeast (either wild or added) begins turning glucose into alcohol, accelerating its activity as the fermentation progresses.

Fresh rice koji is naturally home to LAB. When combined with water and rice, these bacteria flourish, creating a “biological shield” of acidity that prevents spoilage while providing a signature tartness.

This process results in a fascinating liquid evolution. By Day 2, the mash contains almost no alcohol. Instead, it is a “Sour Amazake”—a thick, creamy porridge that is sweet, deeply umami, and punchy with lactic acidity. As the days progress, the yeast takes the lead and the alcohol content begins to climb. Depending on when you choose to stop the fermentation, the ABV typically falls between 6% and 14%.

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Kvass is a fermented beverage with a lineage spanning over a millennium in Eastern European culinary traditions. Traditionally described as a lightly carbonated, sweet-and-sour liquid, it is produced through the fermentation of stale rye bread using a sourdough starter. This process yields a functional probiotic beverage that bridges the gap between traditional fermentation technique and modern culinary world. It is a cornerstone of zero-waste cooking, transforming bread scraps into a complex, restorative tonic.

Authentic kvass relies on a natural process called simultaneous fermentation. Unlike modern commercial versions that use isolated laboratory yeast and artificial carbonation, this method employs the living community of microbes found in a sourdough starter. This community consists primarily of Lactic Acid Bacteria (LAB) and wild yeast. When managed correctly, these microbes produce a drink that is nearly non-alcoholic, highly acidic, and rich in depth.

How the Microbes Work

The character of kvass is defined by two main types of microscopic helpers. The most important are Lactic Acid Bacteria (LAB), such as Lactobacillus. These bacteria consume the sugars in the rye extract and convert them into lactic acid. This acid is what provides the signature sharp “zing” of the drink. It also lowers the liquid’s pH, which acts as a natural preservative by making the environment too acidic for undesirable bacteria to grow.

Working alongside the bacteria is wild yeast, known as Saccharomyces cerevisiae. In a typical beer or wine fermentation, the yeast is the star, turning sugar into high amounts of alcohol. However, in authentic kvass, the yeast plays a supporting role. It provides a very light, natural fizz (carbonation) and contributes subtle fruity aromas. By focusing on the bacteria rather than the yeast, we ensure the beverage stays functional and refreshing rather than boozy.

A third group, Acetic Acid Bacteria (AAB), often joins the process. These bacteria feed on the tiny amounts of ethanol produced by the yeast and turn it into acetic acid—the same acid found in vinegar. In small amounts, this adds a complex, tangy layer that balances the deep, caramelized notes of the toasted rye bread.

Temperature is Your Control Tool (Key to Lacto-Fermentation No.1)

In fermentation, temperature acts like a steering wheel. By choosing a specific temperature range, we decide which microbes will be the most active. For authentic kvass, we aim for a consistent range of 20–22°C.

This specific range is the “sweet spot” for Lactic Acid Bacteria. It is warm enough for the bacteria to thrive and produce that necessary acidity, but cool enough to suppress the wild yeast activity that prefers higher temperatures. If the environment gets too warm (above 25°C), the yeast takes over, leading to higher alcohol levels and a “bready” flavor that masks the clean, sharp profile we want to achieve.

Sugar Concentration (Key to Lacto-Fermentation No.2)

The concentration of sweetener is just as vital as the temperature for guiding the fermentation path. For Lactic Acid Bacteria, a sugar level of approximately 10% is perfect. At this concentration, the LAB can efficiently convert sugars into lactic acid without being outcompeted by other microbes.

Higher sugar levels are typically preferred by yeast and lead to a significant shift toward alcoholic fermentation. When the sugar concentration is too high, the yeast becomes the dominant force, producing more ethanol and carbon dioxide while the production of beneficial lactic acid slows down. Maintaining a 10% sugar ratio ensures the drink remains refreshing, acidic, and nearly non-alcoholic.

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The Culinary Logic of Toasted Bread

The base of kvass is more than just a flavor choice; it is a chemical necessity. By toasting stale rye bread at high heat, we trigger the Maillard reaction. This is the same process that makes a seared steak or a roasted coffee bean taste so good.

Toasting creates dark, complex pigments and toasted aromatic compounds that the water can then extract. It also makes the starches in the bread more accessible to the microbes. The result is a liquid that has the color of dark amber and a flavor profile reminiscent of coffee, caramel, nuts, and toasted grain.

Recipe: Traditional Sourdough Kvass

This recipe produces approximately 1.75 liters of kvass. It is designed to be low-cost and requires no specialized equipment beyond a thermometer and a standard glass vessel.

Ingredients

• 200g Stale Rye Bread: Ground or crushed. This your flavoring agent.

• 200g Sweetener: Sugar, jaggery, or honey. This acts as the primary fuel for the Lactic Acid Bacteria.

• 50g Sourdough Starter: Use an active, living culture.

• 2 Liters Filtered Water: Use chlorine-free water to ensure the health of the live microbes.

• 3–4 Fresh Mint Leaves (Optional): Added for a bright, refreshing finish.

Method

1. Toast the bread: Roast the rye bread in an oven at 180°C until it is dark brown and fully crisp. Ensure the bread is dark throughout to maximize the color and flavor of the final extract. It could be the color of roasted coffee beans. It must not be charred.

2. Extract the base: Boil 0.75 liter of the filtered water. Pour the boiling water directly over the toasted bread in a heat-safe vessel. Allow this to steep for at least 30 min to extract the aromatics.

3. Sweeten and flavor: Stir in the 200g of sugar (preferrably raw or jaggery) until it is completely dissolved. If you’re using honey, do not add it while the mixture is hot.

4. Adjust the temperature: Once steeped, add the remaining 1.25 liter of cool filtered water. Check that the liquid has cooled to between 20–30°C. Adding the starter to liquid hotter than 35°C will kill the beneficial bacteria.

5. Add honey and the mint leaves at this stage if you are using them.

6. Inoculate: Stir in the 50g of sourdough starter.

7. Ferment: Seal the vessel. Store the vessel in a dark spot at a steady 20–22°C for 2-3 days.

8. Cold Crash: Move the vessel to the refrigerator at 4°C for 12-24 hours. This cold temperature causes the bread solids and yeast sediment to settle at the bottom, clarifying the drink.

9. Rack and bottle: Carefully pour the clear liquid into clean bottles, leaving the sediment behind.

10. Store: Keep the finished kvass in the refrigerator at 4°C. It is ready to drink immediately and will stay fresh for up to 7 days.

Success Parameters

• Inoculation Temperature: 20–30°C

• Fermentation Temperature: 20–22°C

• Fermentation Time: 48-72 Hours

• Final Target pH: 3.5–3.8 (This ensures the drink is crisp and acidic)

• Storage Temperature: 4°C

Your mature kvass can work as a starter for your next batch or for other lacto-fermented sodas:

Don’t have your own sourdough starter? It’s very easy to make - you only need flour and water. Here’s our fool-proof recipe that always works:

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cosmos society

This recipe explores the deep complexity of cherry through three distinct dimensions: fresh (raw puree in the meringue), heat-treated (cooked in the syrup), and fermented (via our house-made cherry kvass). The result is a sophisticated, aerated confection with a mild lactic tang and a fermented malt finish.

This recipe is developed by Irina Pashkova, the visionary pastry chef behind the signature flavor architecture of Cosmos Society. As the co-author of the Fermentation in Desserts guide, Irina’s work exists at the precise intersection of microbial science and high-confectionery architecture. Her work exists at the precise intersection of microbial science and high-confectionery architecture, where flavor is treated as a structural element rather than a mere additive. By utilizing deep fermentation cycles and rigorous technical standards, Irina moves beyond traditional sweetness to redefine the sensory and textural boundaries of modern pastry.

For us, authenticity is non-negotiable: our kvass is fermented exclusively with a sourdough starter, relying on wild cultures to unlock that signature depth.

Note: If you don’t have access to house-fermented cherry kvass, substitute with a high-quality, sourdough-based (lacto-fermented) kvass.

Cherry Kvass Zefir Recipe

Ingredients

Meringue Base

• 100g Apple Puree (High pectin, reduced)

• 30g Cherry Puree

• 8.5g Egg White Powder (Albumin)

• 70g Fine Granulated Sugar

Cooking Syrup

• 200g Fine Granulated Sugar

• 50g Glucose Syrup (43 DE)

• 9g Agar-Agar (900 Bloom)

• 185g Cherry Kvass (or plain sourdough kvass)

• 40g Cherry Puree

Finishing

• Dextrose or Icing Sugar (for coating)

Method

Hydration: Combine apple puree, 30g cherry puree, and albumin in a stand mixer bowl. Allow to hydrate for 10-15 minutes. Stir in 70g sugar.

Syrup Prep: In a heavy-bottomed saucepan, combine all syrup ingredients. Begin cooking over medium heat, stirring constantly to activate the agar-agar.

Aeration: While the syrup heats, begin whipping the puree mixture. Start on medium, increasing to maximum velocity until the mass achieves stiff peaks and high density.

Thermal Concentration: Cook the syrup to 110C. It should reach a "heavy thread" stage, falling from the spatula in slow, viscous droplets.

Emulsification: With the mixer on high, pour the hot syrup into the meringue in a steady, thin stream. Continue whipping until the temperature drops to 50–55C and the whisk leaves sharp, permanent tracks.

Depositing: Quickly transfer to a piping bag. Pipe onto parchment immediately, as the agar begins to set below 40C.

Stabilization: Allow to stabilize at room temperature for 12–24 hours (depending on humidity) until a dry "skin" forms.

Finishing: Pair the halves and dredge in dextrose or icing sugar to neutralize tackiness. Store in an airtight container for 5–7 days.

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Most people think of flavor as a single note, but in professional pastry, we build it like a chord. For this zefir, we’ve deconstructed the cherry into three distinct states to create a profile that is as complex as a fine wine:

The Fresh Dimension (The Brightness): By using frozen cherry puree in the meringue base, we preserve the volatile aromatic compounds and the natural acidity of the fruit.

The Thermal Dimension (The Depth): In the syrup phase, we heat-treat the cherry. This caramelizes the natural sugars and creates a jammy, deep "base note" that grounds the sweetness.

The Fermented Dimension (The Soul): Using our lacto-fermented Cherry Kvass introduces a mild lactic tang and a malty, funky complexity you simply can’t get from fruit alone. It’s the secret to that sophisticated, "grown-up" finish.

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Irene Pashkova
cosmos society

We’ve been through the toughest shifts before, and we’ll get through this one too. With the current challenges hitting our industry, we know many of you are facing unexpected downtime, unpaid leaves, or the stress of what’s next. It feels a bit like 2020 again, but we aren’t going through it alone.

The UAE is more than just a place of work; for so many of us in the hospitality industry, this is our home. During these times of change, we want to thank the UAE government for their unwavering commitment to doing everything they can to protect us and ensure our community remains resilient.

A Non-Profit Mission for Culinary Innovation

In the spirit of solidarity, Denis Pashkov—a fermentation consultant and expert in culinary innovation—is launching a Free Online Fermentation Workshop with certification for all UAE-based chefs and hospitality professionals.

Instead of letting this time go to waste, cosmos society team are offering their expertise in lacto-fermented sodas and koji applications, as well as in bio-culinary science to help our community sharpen its tools. This is a strictly non-profit initiative designed to provide a space where we can keep our passion alive without the burden of costs or expensive kits.

What the Initiative Includes

We want to offer a space to learn, grow, and experiment together. The online workshop focuses on high-level expertise made accessible for any kitchen:

• The Science of Fermentation: Deepening your understanding of the “why” behind the craft.

• Zero-Equipment Demos: Techniques you can replicate at home with no special kits required.

• Koji Applications: Specialized insights into the versatility of Koji in modern culinary innovation.

Denis Pashkov and the Cosmos Society believe that by leaning on each other and sharing our expertise, we ensure that the UAE’s culinary scene remains the best in the world. Let’s use this time to uplift each other and prepare for the next chapter.

We will come back stronger than ever!

How to Book Your Spot

This webinar is open to all UAE-based hospitality professionals. To join this non-profit session, please reach out directly:

Hit the DMs to book: @salut.denis on Instagram.

This process yields a butter unlike any traditional dairy ferment. The final product is defined by a pronounced floral fragrance and distinct notes of tropical coconut. While standard cultured butter is characterized by a sharp, lactic tang, this koji-driven version offers a sophisticated, natural sweetness balanced by only a very mild, background acidity. The texture is dense and luxurious, resulting from a deep biological transformation of the milk fats and proteins.

The Science of Koji-Driven Transformation

When you introduce fresh koji rice to heavy cream, you are launching an enzymatic takeover. While wild Lactic Acid Bacteria (LAB) are present, the primary drivers of flavor and texture in this 36-hour window are the enzymes produced by the Aspergillus oryzae mold.

Natural LAB Activity: While enzymes drive the aromatics, the process is anchored by wild Lactic Acid Bacteria naturally occurring on the fresh koji rice. These bacteria, primarily of the Lactobacillus and Pediococcus genera, thrive during the36-hour incubation at 23-27°C. As they consume liberated sugars, they produce trace amounts of lactic acid, providing a foundational “bright” note that balances the deep sweetness and ensures microbiological stability.

Proteolytic Thickening: Koji produces proteases. These enzymes break down milk proteins (specifically caseins) into smaller peptides. This process, similar to the action of rennet in cheesemaking, causes the proteins to aggregate and form a gel-like structure, thickening the cream without necessarily requiring a high level of acidity.

Lipolytic Texture Changes: Koji also contains lipases, which break down milk fats into free fatty acids. This alters the viscosity and mouthfeel, contributing to the “thick” and “heavy” texture.

Lactose Conversion: Koji produces lactase, an enzyme that splits lactose into glucose and galactose. Because these simple sugars are significantly sweeter than lactose, the resulting buttermilk and butter retain a noticeable, natural sweetness.

Aromatic Synthesis: The “floral and coconut” notes are the result of lipases breaking down milk fats into esters. These aromatic compounds are highly volatile and provide a sensory experience far more complex than the “sour” profile of standard cultured butter.

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Recipe: Koji-Cultured Butter

A clinical guide to producing enzyme-transformed butter with a sweet, floral profile.

Ingredients

• 1000g Heavy Cream (35.1% fat)

• 50g Fresh Koji Rice

Method

• Inoculate: Combine the heavy cream and fresh koji rice in a clean glass jar.

• Stir: Agitate the mixture thoroughly to ensure the koji is fully submerged.

• Culture: Maintain the mixture at a constant 25°C for 36 hours.

• Monitor: Check for a floral aroma and a significant increase in viscosity.

• Chill: Place the thickened cream in a refrigerator at 4°C for at least 6 hours to stabilize the fats.

• Strain: Pass the chilled cream through a fine-mesh sieve to remove the rice grains. Congrats, you’ve just made koji crème fraîche!

• Churn: Beat the strained cream on medium-high speed until the fat solids separate from the liquid.

• Drain: Collect the buttermilk; it will be sweet and fragrant due to the enzyme-driven sugar conversion.

• Wash: Rinse the butter solids in ice-cold water. Fold and press the butter until the water runs clear.

• Store: Form into blocks and refrigerate.

Koji butter is the result of a precise synergy between fungal enzymatic activity and dairy science. By moving beyond simple acidification, this method unlocks a rare aromatic spectrum of esters and simple sugars, resulting in a product that is both technically complex and culinarily distinct. You may also use shio-koji to ferment your butter: the product will be different, but still delicious.

This is a high-fragrance gastronomic butter designed for finishing, not frying. Due to the increased concentration of simple sugars, it has a low smoke point and will burn quickly over high heat. It is exceptional when served with warm bread, delicate seafood, or roasted vegetables. For a deeper umami profile, try folding in a small amount of red miso. The byproduct buttermilk is naturally sweet and makes an incredible glaze.

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Irene Pashkova
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Want to get inspiration and create your way of using this unique butter? Check out the Fermentation in Desserts guide by Irina Pashkova and Denis Pashkov:

Kombucha is often relegated to the “health food” aisle, but in Giorgio’s hands, it becomes a sophisticated tool for flavor development. By manipulating the base tea—ranging from the robust tannins of Kenyan Black tea to the earthy, chocolatey notes of Cacao Tea—he creates a complex acidic profile that can rival the finest citrus in a highball or serve as a standalone, nuanced aperitivo.

The Science of the SCOBY

The magic of kombucha lies in the SCOBY (Symbiotic Culture of Bacteria and Yeast). When introduced to sweetened tea, the yeast converts sugar into ethanol and carbon dioxide. Simultaneously, acetic acid bacteria (AAB) consume that alcohol, transforming it into the bright, sharp organic acids that give kombucha its signature “zing.”

Giorgio likes his kombucha acidic. By fermenting to roughly ten days and using mineral-light water to avoid inhibiting the delicate microbial colony, he produces a liquid that is as much a culinary ingredient as it is a beverage.

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Recipe: Giorgio’s Core Kombucha Recipe

This recipe is adapted from Giorgio’s personal method, optimized for a balanced fermentation that respects the SCOBY’s health while delivering the bold, acidic punch required for modern cocktails.

Ingredients

• Water: 1 Liter of soft mineral water (Filtered water is preferred; high chlorine or “hard” water can stress the culture).

• Tea: 15–20g of high-quality loose-leaf tea (Black, Green, Rooibos, or Cacao tea).

• Sugar: 100–110g Organic Cane Sugar or Muscovado (Note: Muscovado adds a deep molasses funk but can be more challenging for beginners).

• Starter Liquid: 100ml of previously fermented kombucha (This lowers the pH to prevent mold).

• The Mother: 1 healthy SCOBY.

Equipment

• 1.5L Wide-mouth glass jar

• Breathable cotton cloth or “nut milk” bag

• Heavy-duty elastic band

• Digital thermometer

Instructions

1. The Brew: Bring half of your water (500ml) to just under a boil (roughly 90°C). Steep your tea for 5–7 minutes. If using Matcha, whisk it thoroughly to avoid clumps.

2. The Sweetener: Stir in the sugar while the tea is hot until completely dissolved.

3. The Tempering: Add the remaining 500ml of cold mineral water. This helps bring the temperature down quickly.

4. Inoculation: Ensure the liquid has cooled to between 20°C and 26°C. Colder is fine, but will take longer to kick off the active fermentation.

Note: Do not add the SCOBY if the liquid is above 30°C, as this can kill the living bacteria.

1. The Setup: Pour the tea into your glass jar. Add the SCOBY and the 100ml of starter liquid. The starter liquid is either your mature kombucha from the previous batch, or your liquid from the same bag as your SCOBY if it’s freshly bought.

2. The Ferment: Cover the jar with the cotton cloth and secure it with the elastic band. This allows the bacteria to breathe (aerobic fermentation) while keeping out fruit flies.

3. The Wait: Store the jar in a dry, dark place with good air circulation. Taste the brew with a clean straw starting at day 5.

4. The Finish: Once you reach your desired acidity (usually around day 10), remove the SCOBY and a small amount of liquid for your next batch. Filter the remaining liquid through a fine-mesh sieve.

5. Flavoring (Optional): If you want to follow Giorgio’s lead, add fresh green apple or forest fruits (blueberries, raspberries) to the bottled liquid and let it sit for 2 days at room temperature for a “second fermentation” before moving it to the fridge.

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This soda is designed for exact food pairing. We use Lactic Acid Bacteria (LAB) to turn a mandarin base into a complex drink. Its sharp acidity and roasted rye notes make it a versatile culinary tool. It balances fatty roasted poultry and contrasts well with dark chocolate or coffee desserts.

The Role of Lactobacillus

The primary driver of this ferment is Lactobacillus. We introduce it using a mature, sourdough-cultured rye kvass. These bacteria convert sugars into lactic acid and carbon dioxide. This process creates a clean, tart flavor that is much smoother than kombucha.

The Sourdough Rye Kvass Starter

The success of this ferment depends on the mature rye kvass used as a starter. This kvass is brewed with toasted rye bread and raw sugar, then inoculated with a sourdough starter. We ferment the kvass at a cool 20–22°C to specifically cultivate a high concentration of LAB. By using a mature, active liquid culture instead of salt, we jumpstart the soda’s fermentation and ensure a dominant, healthy bacterial population from the first hour.

For the detailed authentic kvass recipe refer to this page:

Vacuum-Concentrated Flavor

We use Andros Chef Mandarin Confit instead of standard juice. This product is made in a vacuum chamber to remove water without using high heat. This method protects the fresh fruit aroma. It provides a consistent, intense citrus profile that does not fade during fermentation. This is our only source of sugar that utilizes the natural sugars of the fruit.

Temperature and Microbial Control

Keep the fermentation temperature between 20–22°C. This range helps the LAB stay active and healthy. It also prevents wild yeast from taking over. Proper temperature control ensures the soda stays crisp and avoids any “bready” off-flavors.

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Lacto-Fermented Mandarin Soda Recipe

This guide produces 1 liter of high-acid soda for professional culinary use.

Ingredients

• 720 ml Water: Filtered and chlorine-free.

• 100 ml Mature Rye Kvass: Toasted rye base, sourdough-started (microbial starter).

• 180 g Andros Chef Mandarin Confit: 56% sugar content (mostly natural sugars of mandarin)

  • Note: This adds 100.8g of natural sugar, providing approximately 10°Bx to the mix.

Method

1. Combine the 180g of mandarin confit with 200ml of the water.

2. Whisk or blend until the mixture is completely smooth.

3. Add the remaining 520ml of water and the 100ml of mature kvass.

4. Pour the liquid into a 1L pressure-rated bottle.

5. Seal the cap tightly to trap the natural carbonation.

6. Ferment at a stable 20–22°C for 36–48 hours.

7. Chill the bottle to 4°C once it reaches the target pH to stop the fermentation.

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Milk kefir whey sodas are bright, tart, and full of microbial life. They are made by fermenting a liquid medium with the clear whey strained from milk kefir. The result is a soda with clean acidity, subtle complexity, and natural carbonation.

This fermentation relies on a living culture of lactic acid bacteria and yeast. The microbes convert sugars into organic acids, carbon dioxide, and aromatic compounds. The process produces a drink that is refreshing, lightly effervescent, and microbiologically active.

Clear kefir whey works especially well with delicate fruits. Mango, peach, lychee, and floral fruits show excellent balance with its smooth lactic acidity.

A Versatile Fermentation Starter

Milk kefir whey is a powerful fermentation starter. It contains a dense population of lactic acid bacteria (LAB) and yeast. The liquid is also naturally low in lactose.

Researchers have identified more than forty microbial strains in milk kefir cultures. This diversity makes the culture adaptable and stable.

The microbes can ferment many sugars. These include lactose, glucose, fructose, sucrose, and maltose.

The culture also tolerates a wide temperature range. Fermentation works reliably between 12 °C and 30 °C.

This resilience allows fermentation even when conditions are not perfectly controlled. The culture adapts easily to different fruits and seasonal temperature changes.

LAB and Yeast Symbiosis

Milk kefir fermentation is driven by cooperation between bacteria and yeast.

Common lactic acid bacteria include:

• Lactobacillus kefiranofaciens

• Lactobacillus kefir

• Lactobacillus paracasei

• Leuconostoc mesenteroides

These bacteria convert sugars into lactic acid and small amounts of carbon dioxide. The acid lowers the pH and creates a protective environment.

Several yeasts are also present in kefir cultures. The most common include:

• Saccharomyces cerevisiae

• Kluyveromyces marxianus

Yeasts contribute to natural carbonation and insignificant amounts of alcohol. They also produce aromatic compounds that add complexity.

Whey contains very little fat and protein. This makes it ideal for clear fermented sodas. At the same time, it remains rich in peptides, amino acids, and minerals. These nutrients support microbial growth.

Lactic acid bacteria metabolize sugars quickly. The pH drops rapidly during fermentation. This acidification suppresses many spoilage organisms.

Preparing the Whey Starter

Phase 1: Culturing Milk Kefir

Milk kefir grains look like small cauliflower clusters. They are soft, gelatinous, and cream-colored.

Ingredients

• 1 L milk

• 1 tbsp milk kefir grains

Method

1. Combine the milk and kefir grains in a glass jar.

2. Ferment at 21–27 °C for 24 hours.

3. Strain the liquid through a plastic strainer.

4. Keep the grains for the next batch.

5. The grains multiply over time. Discard or share the excess.

6. Feed the grains fresh milk daily at room temperature. Feed once per week if refrigerated.

Phase 2: Extracting Milk Kefir Whey

Ingredients

• 1 L freshly strained milk kefir

Method

1. Leave the kefir at room temperature for 12-24 hours.

2. Wait until solid curds separate from the liquid.

3. Line a strainer with fine mesh cloth.

4. Transfer the kefir gently into the strainer.

5. Allow the liquid to drip naturally. Do not press the solids.

6. After one hour, return the collected liquid to the strainer.

7. Continue draining until the whey becomes completely clear.

8. Collect the liquid for 6-12 hours.

9. Use the clear whey as a fermentation starter.

10. The remaining curds can be eaten or used as fresh cheese.

Calculating the Starting Brix

Fruit sodas need enough sugar for fermentation. The starting sugar level should be 8–10 °Bx.

1 °Bx equals 10 g of sugar per kilogram of liquid.

An 8–10 °Bx fermentation therefore requires 80–100 g of total sugar per kilogram of soda base.

Check the nutritional label of your fruit puree. Calculate the natural sugar content. Then adjust the amount of added sugar.

Formula

Sugar to Add (g) = Target Sugar (g) − (Puree Weight (g) × Puree Sugar %)

Example:

250 g mango puree at 19 % sugar contains 47.5 g natural sugar.
Adding 45 g sugar produces a starting level close to 9 °Bx, which is ideal for fermentation.

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Lacto-Fermented Mango Soda

Ingredients

• 250 g Andros Chef mango puree

• 45 g white sugar

• 100 ml milk kefir whey

• 600 ml drinking water

Method

1. Combine mango puree, sugar, whey, and water in a clean container.

2. Keep the mixture below 30 °C.

3. Ferment for 2 days at 20–22 °C.

4. Move the container to the refrigerator for 1 day.

5. Remove it carefully without shaking.

6. Rack the liquid off the sediment.

7. Strain through a fine filter or super-bag.

8. Bottle the soda.

9. Seal the bottles tightly.

10. Store below 6 °C and consume within 6 days.

The result is a lightly sparkling mango soda with balanced acidity, natural fermentation character, and a vibrant fruit aroma.

Milk kefir whey is one of the most adaptable fermentation starters available to beverage makers. Its microbial diversity allows it to ferment many different sugars and fruit substrates. The culture works reliably across a wide temperature range and under simple conditions.

This flexibility makes whey ideal for experimentation. Mango, berries, stone fruits, herbs, and floral ingredients all respond differently during fermentation. Small adjustments in sugar, temperature, or fruit concentration can produce entirely new flavor profiles.

For fermentation-driven beverage programs, this versatility is a major advantage. A single culture can generate an entire family of seasonal sodas while maintaining a consistent microbial backbone.

Fermentation is nature’s way of unlocking hidden flavors. Among its many wonders, shio koji stands out as a simple yet transformative Japanese seasoning. Made from just three ingredients—rice koji, salt, and water—it harnesses the power of enzymes to break down proteins and starches. The result is a savory, slightly sweet paste (or liquid) that elevates meats, vegetables, and sauces.

Why Make Shio Koji?

Shio koji is more than a condiment. It’s a natural flavor enhancer, a meat tenderizer, and a fermentation booster. Unlike commercial MSG, it delivers umami through enzymatic action, not additives. Chefs and home cooks use it to:

• Boost depth in soups and broths.

• Tenderize proteins without acidity.

• Accelerate pickling while preserving texture.

• Replace salt in recipes with a more complex taste.

The Science Behind Shio Koji

Shio koji is not a microbial ferment like sauerkraut or kimchi. Instead, it relies on enzymes produced by Aspergillus oryzae, the mold cultured on rice koji. These enzymes perform two key reactions:

1. Proteases break down proteins into amino acids, creating savory umami (glutamate).

2. Amylases convert starches into simple sugars, adding sweetness.

While microbes like Lactobacillus may grow if conditions allow, they are not the primary drivers. The process is controlled by salt concentration (8–12%), which suppresses unwanted bacteria while letting enzymes work. The activity of protease enzyme will decrease with the addition of high salt concentration approximately 18%.

Critical Fermentation Parameters

For optimal enzyme activity, shio koji requires precise conditions:

• Temperature: 25–30°C – Warmth accelerates enzymes without denaturing them.

• Hydration: A 1:1 minimum water-to-koji ratio ensures proper enzyme diffusion. Less water slows reactions, exposes floating bits to unwanted mold development.

• pH: 5.0–6.5 initially, dropping to 4.5–5.0 as mild acidity develops.

• Time: 7–10 days. Umami levels will be rising insignificantly after 7-8 days of fermentation with 10-12% salt concentration.

Daily stirring prevents surface drying, mold development, and evenly distributes enzymes. Refrigeration halts activity once the desired taste is achieved.

How to Use Shio Koji in Cooking

Shio koji’s versatility makes it a kitchen staple. Here are a few applications:

1. Meat Marination

• Coat poultry, beef, or fish in shio koji (10% of weight).

• Marinate for 2–24 hours (longer for tougher cuts).

• Proteases break down muscle proteins into free amino acids, particularly glutamates that boost umami.

2. Vegetable Pickling: Shiokojizuke

• Replace 20% of salt in brine with shio koji. To replace salt completely, use 1 part of shio koji to 4 parts of vegetables+liquid weight—in this case, you are making Shiokojizuke.

• Ferments vegetables faster while keeping them crisp.

3. Umami Seasoning

• Blend into dressings, soups, or stir-fries.

• Adds depth without overpowering.

Maillard Reaction Booster

When meat is marinated in shio koji and grilled, we get a more pronounced sweetness and complexity, which may be explained by the following factors:

1. Amino Acid Release (Proteolysis)

   • Shio koji’s proteases break down meat proteins into free amino acids (especially glutamic acid, alanine, and glycine).

   • These amino acids participate in the Maillard reaction (140–165°C), creating more complex browning and roasted flavors compared to plain meat.

2. Surface Dehydration

   • The salt in shio koji draws moisture to the meat’s surface.

   • During frying, this reduces steam interference, allowing for:

     • Faster Maillard reactions (which require <15% moisture).

     • Direct contact between amino acids and heat for caramelization.

3. Flavor Synergy

   • Free glutamates (umami) amplify kokumi (richness), making sweet notes taste more pronounced.

   • Minor lipid oxidation (from koji lipases) adds nutty, buttery undertones that complement caramelization.

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That environment inevitably influences my work. When I develop beverages for Ramadan, I’m thinking about more than flavor — I’m thinking about hospitality, nourishment after fasting, and drinks that restore energy while honoring the spirit of the month. Fermentation, with its balance of function and pleasure, becomes a natural language for that expression.

🌙 For this Ramadan, I’ve been focusing on beverage menus that feel celebratory, functional, and deeply rooted in fermentation.

One concept I’m especially proud of is a probiotic-rich, lacto-fermented amazake soda. I ferment koji with water at low temperatures, allowing enzymes to unlock natural sweetness and umami, while lactic acid bacteria gradually convert sugars into a clean, thirst-quenching acidity. The result is layered, complex, and naturally balanced before any flavoring is added.

For the secondary fermentation, I introduce Andros Chef prickly pear purée — for the flavor, and I’ll admit, also for the appearance. The color is too beautiful to ignore. A touch of saffron adds warmth and aromatic depth, tying the drink back to the regional flavor palette.

It’s an ideal pairing for iftar: rich in flavor yet refreshing, balancing acidity, natural sweetness, and umami depth. No added sugar, alcohol-free, and alive with beneficial cultures — a beverage that supports the body as much as it excites the palate.

I love helping restaurants and brands develop Ramadan beverage programs that go beyond the expected and bring fermentation into a modern, commercial context.

✨ If you’re planning a seasonal drinks menu and want to explore probiotic, fermentation-driven concepts, we’d be glad to connect.

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Sour amazake a less known brother of sweet amazake.

While both sour and sweet amazake rely on the metabolic power of koji (Aspergillus oryzae), sour amazake shifts the focus away from rapid sweetness and toward microbial balance, controlled acidity, and umami-driven complexity. It is not simply an unheated version of sweet amazake; it is a distinct fermentation ecosystem shaped primarily by temperature, time, and microbial succession.

Reference Point: Sweet Amazake

Sweet amazake is produced by holding rice and koji at 50-60C, a temperature range optimized for a- and ẞ-amylase activity, which is heat-driven saccharification.

These enzymes rapidly hydrolyze gelatinized starch into glucose and maltose, creating high sweetness in a short time (7-10 hours).

At these elevated temperatures, lactic acid bacteria growth is inhibited, and proteolytic enzymes play a minor role.

The result is a clean, sweet, low-acidity beverage with limited umami development.

Fermentation Dynamics

Sour amazake ferments at 20-23C, where koji enzymes remain active but operate more slowly.

Amylases gradually convert starch into fermentable sugars, while acid proteases and peptidases break rice proteins into amino acids and small peptides.

This balanced enzymatic activity increases umami, mouthfeel, and savory depth, creating a substrate not only for sweetness, but also for subsequent microbial fermentation and flavor layering.

Slower conversion, broader flavor formation.

This environment strongly favors lactic acid fermentation. Lactic acid bacteria (LAB) are naturally present on koji rice, cooled cooked rice, and in the environment. At moderate temperatures, mesophilic LAB such as Lactobacillus and Leuconostoc proliferate without added starters. Crucially, the 20–23C range encourages LAB dominance over less desirable microorganisms. Yeasts remain largely inactive, preventing alcohol production, while spoilage bacteria are outcompeted as acidity begins to develop. Temperature here is not incidental—it is selective pressure.

These bacteria metabolize glucose and maltose into lactic acid, gradually lowering pH. This acidification is not abrupt or aggressive. Instead, it progresses in parallel with enzymatic sugar release, allowing the ferment to self-regulate. Acidification stabilizes the ferment, suppresses spoilage microbes, and introduces soft, rounded acidity rather than sharp sourness. The result is a profile closer to yogurt whey or lightly cultured rice water than to vinegar or kombucha.

From a beverage perspective, this makes sour amazake unusually versatile. It is refreshing yet savory, acidic but restrained, and structurally stable.

Sounds like a starter for lacto-fermented sodas that also layers your beverage with umami, doesn’t it?

Because sugars are still present but partially consumed, sour amazake can support secondary fermentations, carbonation, or flavor infusions without becoming cloying or volatile.

Temperature is Your Control Tool

The entire process hinges on thermal restraint and precision. The process unfolds in two phases. During the first 2-3 days at 20–23°C, enzymatic saccharification and LAB growth occur simultaneously, building sugars, amino acids, and acidity. This phase is dynamic and biologically active, requiring daily stirring to redistribute nutrients, oxygen, and microbes evenly. Stirring also prevents development and ensures uniform enzyme access.

Once the desired balance begins to emerge, refrigeration becomes essential. Refrigeration below 6C slows microbial metabolism while enzymatic reactions taper off. LAB activity is not stopped entirely, but it is significantly reduced, allowing the ferment to stabilize rather than continue acidifying unchecked.

This cold conditioning stabilizes pH, prevents over-acidification, and allows flavor integration, resulting in a clean, complex, mildly sour amazake with pronounced umami. Time in the cold becomes a refinement stage rather than an active fermentation phase.

Sour Amazake Core Recipe

Ingredients:

• 700 gr Koji Rice

• 1000 gr Water

Instructions:

Mix well all the ingredients at room temperature. Make sure all the rice is submerged.

• Ferment at 20–23°C for 3 days. Stir EVERY DAY.

• Strain off the grains.

• At this stage, you may add flavoring agents (fruit, herbs, spices) for the secondary fermentation.

• Ferment in the fridge for up to 3 days—the longer you ferment, the more acidity it develops.

• Strain through a chinois, then through a super-bag (nut milk bag).

Store below 6°C for up to 7 days.

Last Sunday, we hosted our latest Lacto-Fermented Sodas Workshop in Dubai, bringing together a diverse group of chefs, bartenders, and fermentation enthusiasts united by a shared curiosity: how can fermentation become a natural source of acidity, sweetness, and carbonation—without added sugar?

Across the session, we explored the core ferments that form the backbone of modern, low-sugar, microbially driven sodas. Rather than relying on commercial starters or refined sugar, participants learned how living cultures can create vibrant, functional beverages through natural enzymatic and bacterial processes.

What We Covered

The workshop focused on five foundational ferments, each offering its own microbial ecosystem and creative potential:

• Ginger Bug – the wild, versatile starter that forms the foundation of naturally carbonated sodas. Participants made their own ginger bug to take home and nurture.

• Water Kefir – a clean, fruit-sugar–driven ferment producing probiotic, naturally sparkling drinks.

• Whey-Based Sodas – using whey’s 40+ beneficial strains to build complex acidity and gentle sweetness.

• Sour Amazake Sodas – merging koji’s enzymatic transformation with lacto-fermentation for layered, no-added-sugar flavors.

• Modern Kvass – a fresh interpretation of Eastern European tradition, balancing grain, fruit, and acidity.

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To explore flavor in a clean and controlled way, we used Andros Chef frozen fruit purées, which offered consistency, clarity, and natural brightness without the need for added sugars or artificial aromatics. Their purity made it easier to understand how each ferment develops character across its stages.

What Participants Took Home

Everyone left with:

• A living ginger bug starter they built themselves

• Active kefir cultures

• Koji to continue experimenting

• Premium access to all the cosmos society materials

• A clearer understanding of how to apply microbial processes to modern beverage development

The aim wasn’t to produce finished sodas on the spot, but to deepen microbial literacy—helping participants recognize the variables that drive fermentation: sugar content in fruits, temperature, pH, microbial balance, and ingredient choice. With this foundation, they can begin building sodas tailored to their own environments, menus, and palates.

Looking Ahead

Workshops like this remind us why fermentation continues to resonate across culinary and beverage communities: it’s sustainable, it’s creative, and it empowers makers to transform overlooked ingredients into something vibrant and functional.

For everyone who joined us on Sunday—thank you. Your questions, curiosity, and willingness to rethink soda through the lens of fermentation made the session truly memorable.

More workshops are coming soon, along with deeper dives into koji, fermented acidity, and zero-waste beverage development. Until then, happy fermenting—and take good care of your ginger bugs.

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Lacto-Fermented Sodas, to me, represent a kind of peaceful rebellion. They’re not engineered for mass appeal or shelf stability; they’re grown. They develop naturally, evolving through the work of bacteria and yeast to create complexity, brightness, and gentle sweetness — sometimes, without any added sugar. They remind us that fermentation is a conversation, not a formula.

This guide is meant to serve both as a learning tool and as an invitation. Whether you’re a home fermenter curious about probiotic drinks, a bartender looking for low-sugar alternatives and new sources of acidity, a chef experimenting with living pairings, or simply someone tired of overly sweet sodas, I hope you’ll find something useful here.

Inside, I cover five of my foundational ferments — Ginger Bug, Water Kefir, Milk Kefir Whey Sodas, Lacto-Fermented Amazake Sodas, and Kvass. Each represents a different microbial world, a unique way to build natural carbonation and balance acidity with sweetness. Although each module explains how to ferment sodas and provides a detailed recipe, they’re not meant to be followed blindly. The recipes are frameworks — flexible systems designed to help you understand what’s happening in your ferment and how to shape it to your taste, ingredients, and conditions.

Rather than chasing perfect results, my goal is to build understanding. Once you learn how temperature, sugar level, and microbial balance affect flavor and activity, you can start to improvise — to localize, adapt, and create your own versions. I want readers to feel confident enough to move beyond recipes and start building drinks that are truly their own.

This guide is for anyone who cares about flavor, sustainability, and creativity. For chefs, it’s a way to turn surplus or forgotten ingredients into vibrant, living drinks. For bartenders, it opens a door to natural acidity and texture without relying on citrus or refined sugar. For those interested in wellness, it offers a simple, practical route to probiotic, functional beverages.

At its heart, The Lacto-Fermented Sodas Guide is about learning to work with nature instead of against it. Every bottle tells a story of patience and transformation — of how something ordinary can become extraordinary when you give microbes the right conditions to do their work.

I hope this guide helps you find that same sense of curiosity and joy in every bubble.

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Lacto-fermentation is both an ancient and surprisingly modern way of preserving foods and unlocking new flavors. The principle is simple: lactic acid bacteria feed on sugars and turn them into lactic acid. This acid gives products a light tang, extends their shelf life, and enriches their flavors with new dimensions. That’s how we get familiar staples like yogurt, sauerkraut, or sourdough bread. But in beverages, lacto-fermentation opens even more possibilities, striking a balance between freshness, acidity, and aromatic complexity.

Kvass is one of the drinks where lacto-fermentation takes center stage. Traditionally brewed from rye or barley malt with a starter culture—and sometimes herbs or berries—kvass always lives somewhere between bread and fruit, sweet and sour. For many, it’s tied to memories of summer, childhood, and a glass of refreshment by the neighborhood yard. But we wanted to see kvass differently: as the foundation for a contemporary drink where tradition meets modern trends.

That’s how our coffee kvass was born. We take malt, a bit of starter culture, and add cold brew coffee. The coffee contributes acidity and chocolate-fruity notes that play beautifully with the malty base. Lacto-fermentation softens and balances the flavor: lactic acid meets coffee acidity to create freshness without sharpness.

To make the drink not only delicious but playful, we serve it in bubble tea form. At the bottom of the glass sit warm, chewy tapioca pearls that add texture and make every sip an adventure. On top, we crown it with foam infused with palo santo—wood known for its warm, aromatic fragrance. We fold our homemade mascarpone into the foam, also the result of lacto-fermentation: cream transformed by kefir grains into a delicate cheese that gives the foam its creamy body. The result is a three-layered drink: malty coffee depth, subtly sweet tapioca, and light, aromatic foam. We call it Boba Kvass.

When we opened Cosmos Brew in Babushkinskaya, our idea was simple: to show that familiar products can be presented in surprising and delicious ways. Coffee kvass felt like a risky move—after all, not everyone imagines kvass and coffee in the same sentence. But this drink quickly became our neighborhood favorite. People love that it’s both recognizable and new. Some recall homemade kvass from their grandmother’s village, while others are discovering fermentation for the very first time.

In this drink, lacto-fermentation isn’t just a trend—it’s the connecting thread. It makes the kvass smooth, the mascarpone rich, and the whole experience cohesive. We never set out to invent “the most unusual bubble tea in Moscow.” We simply wanted to bring together what we love: fermentation, coffee, and a playful approach to form.

Maybe that’s why coffee kvass has caught on so well in Babushkinskaya. It’s become something like a “neighborhood drink”—familiar, yet unique. For us, it’s the best example of how traditions can be adapted into new formats without losing their essence. Lacto-fermentation remains at the heart of it all: the quiet, invisible work of bacteria turning simple ingredients into something greater—leaving us only to share the result with our neighbors and guests.

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On June 30, fermentation came alive in Dubai during a workshop led by Sharon Flynn—bestselling author of Ferment For Good and Wild Drinks—and local fermentation expert Denis Pashkov, hosted as part of the Campari Red Hands program. This hands-on event proved one essential truth: fermentation is easy, approachable, and incredibly rewarding, even for complete beginners (although there also advanced fermentation enthusiasts).

Whether your goal is to make milk kefir at home, brew authentic kvass, or create your own probiotic water kefir sodas, this workshop delivered all the tools and confidence needed to get started—without fancy equipment or prior experience.

Why This Fermentation Workshop Mattered

Today’s beverage landscape is dominated by sugary soft drinks and synthetic flavors. But there’s a better way. By using fermentation, you can craft naturally carbonated, low-sugar, nutrient-dense drinks with just a few ingredients and the right conditions.

The best part? You can do it in your kitchen. This workshop made the process clear, simple, and repeatable—whether you’re a bar professional or a curious home fermenter.

Participants didn’t just learn—they fermented:

• Ginger bug from scratch

• Water kefir grains in action

• Milk kefir whey as a sustainable and forgiving fermentation powerhouse

• Amazake turned into bubbly soda

• Traditional kvass, reimagined for the modern palate

And everyone left with their own starter cultures to continue fermenting at home.

The Science Behind Fermented Sodas

Understanding microbes helps you ferment with confidence

Fermentation is one of the oldest and most natural ways to transform food. In the case of lacto-fermented sodas, we harness the power of lactic acid bacteria (LAB) and wild yeasts to create effervescent, tangy, probiotic-rich drinks—without artificial carbonation or preservatives.

1. Ginger Bug Sodas: Wild Fermentation at Work

A ginger bug is a simple starter made from ginger, sugar, and water. It naturally captures wild yeasts like Saccharomyces and Lactobacillus from the environment.

• These microbes consume sugar, producing CO₂ and organic acids

• The result is a fizzy, complex soda base—your real non-alcoholic ginger beer

• Can be flavored with fruits, herbs, or spices during secondary fermentation

2. Water Kefir: A Flavor Booster

Water kefir grains (SCOBY) transform sugary water into a refreshing, gut-friendly drink.

• Key microbes: Lactobacillus, Acetobacter, and yeasts

• Produces mild acidity and natural bubbles

• Fruit-infused secondary fermentation boosts flavor and fizz

3. Milk Kefir Whey Sodas: Probiotic Powerhouse

Milk kefir doesn’t end with the creamy curds—its whey is a functional ingredient in its own right. This translucent, tangy liquid, rich in LAB and peptides, can be turned into a lightly fizzy soda.

• Diverse culture of bacteria and yeast is able to perform at a wide range of temperatures

• For the same reason, it is able to consume a wide range of sugars

• Rich in probiotics

4. Lacto-Fermented Amazake Sodas: Enzymatic & Microbial Magic

Amazake is a sweet rice drink created by koji mold (Aspergillus oryzae) breaking down starches and proteins.

• When LAB is introduced, the sugars ferment into a light, tangy soda

• No added sugar—just enzymatic sweetness and probiotic sparkle

• A perfect example of traditional Japanese methods meeting innovative soda making

5. Modern Kvass: Reinventing Tradition

Kvass is a Slavic fermented drink made from stale rye bread and wild microbes.

• Dominated by Lactobacillus and wild yeasts

• Toasted bread adds deep flavor, while sourdough starter introduces natural cultures

• Naturally fizzy, tangy, and full of gut-friendly microbes

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Authentic Kvass Recipe (Taught in the Workshop)

No yeast packets, no forced carbonation—just wild fermentation done right.

Ingredients

• 2.5 L hot water

• 200 g raw sugar

• 500 g fermented rye malt (optional but adds complexity and fermentable sugars)

• 100 g sourdough starter (source of LAB and wild yeast)

• 100 g old rye bread, toasted dark (flavoring agent)

Method

1. Steep: Combine hot water and rye malt. Let cool naturally for ~2 hours until below 30°C.

2. Mix: Add sugar, starter, and toasted bread. Stir well.

3. Ferment: Leave at room temperature (20–24°C) for 4 days.

4. Strain: Use a fine sieve or super-bag to remove solids.

5. Condition: Let ferment in the fridge (under 6°C) for another 2 days to carbonate.

6. Bottle & Store: Carefully rack off sediment, bottle, and keep refrigerated. Consume within 10 days.

🔁 Starter tip: Save 200 ml of finished kvass to inoculate the next batch.

You Don’t Need a Lab—Just Curiosity

One of the workshop’s key takeaways? Fermentation is not intimidating. With just basic kitchen tools, clean jars, and a few ingredients, anyone can make living sodas at home.

Whether you're looking to expand your bar menu, cut down on sugar, or just reconnect with real food processes, this workshop made it clear:
Fermentation is easy. Fermentation is fun. And fermentation belongs in Dubai.

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On May 25, Dubai’s fermentation-curious community had the rare privilege of welcoming Rich Shih—fermentation educator, culinary innovator, and co-author of Koji Alchemy—for an immersive workshop dedicated to all things koji. Hosted at the warm and welcoming space of Tahini in One Central, this hands-on gathering was as much a knowledge exchange as it was a sensory exploration of microbial and enzymatic transformation.

The day opened with introductions and an immediate dive into the core subject: how mold-based transformation works and what its applications are. We explored it all — koji’s enzymatic magic, its role in breaking down starches and proteins, and its power to unlock flavors we rarely associate with fermentation. Rich explained how this mold becomes a building block for miso, shoyu, amazake, and countless other fermented foods, both traditional and experimental.

Rich, known not only for his deep technical knowledge but also for his generosity and humility, created a space that felt more like a shared discovery than a formal lecture. Participants, ranging from chefs and bartenders to home fermenters and food creatives, were encouraged to ask questions freely and contribute their own experiences, turning the event into an open dialogue rather than a one-way presentation.

One of the highlights of the workshop was the miso tasting session. Rich brought along an array of miso samples from his personal collection, many of which defied expectations. From nutty and sweet to deep and umami-rich, these misos showcased the wide spectrum of what’s possible when you let koji do the work and lean into curiosity. Some were made with unconventional ingredients—showing that miso is not just a recipe, but a method and mindset that invites adaptation and play.

He also got his hands dirty—literally. Rich walked us through the process of making miso, allowing participants to understand and feel what can’t be conveyed over video or text.

Another exciting ferment was kojizuke—quick pickles made using koji. These fermented vegetables offered an immediate and vibrant expression of enzymatic power, transforming food into something simultaneously familiar and novel. We also explored several types of amazake and other products of koji-based fermentation.

For those curious about how to grow koji at home or in a professional kitchen, Rich Shih and Denis Pashkov demonstrated a basic and accessible setup for koji cultivation. They shared practical tips on temperature, humidity, and airflow—essential conditions for nurturing mold in a controlled, safe, and effective way. It was inspiring to see how such transformative fermentation could be done with humble tools and intentional care.

What made this workshop truly special was its spirit. It didn’t feel like a class—it felt like a community. Rich’s approach was organic, friendly, and generous. Conversations flowed between techniques and stories, science and art, tradition and innovation.

The event was made possible by a collaborative effort between Rich and Dubai’s growing fermentation scene, including Cosmos Society founder Denis Pashkov, whose mission is to make microbial knowledge more accessible and empowering for regional chefs and creatives.

For everyone who joined us, this was more than a workshop—it was a reminder of what happens when curiosity meets community, and when knowledge is shared not as doctrine but as dialogue.

We’re grateful to Rich for bringing his insight, energy, and infectious enthusiasm to Dubai. Here's to more fermentation, more questions, and more shared discoveries.

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Yerevan Cocktail Week 2025 was an absolute triumph—a week of bold flavors, wild creativity, and the kind of warm, generous hospitality that makes Armenia so special. The energy was electric, the drinks were next-level, and the people? Some of the most passionate and welcoming I’ve ever worked with.

One of the highlights for me was the "Fermentation in Desserts" workshop I led alongside the brilliant pastry chef Irina Koroleva at Bar Phoenīx. We dove into how fermentation can transform sweets, turning familiar desserts into something deeper, brighter, and totally unexpected. The star of the show? Cherimoya Amazake Zephyr—a fluffy, marshmallow-like treat where the natural fermentation of amazake brought out the fruit’s tropical pofile while adding a subtle umami depth. The crowd loved it, and the best part was seeing how excited everyone was to experiment with these techniques in their own kitchens and bars.

Armenia’s Unmatched Hospitality & Flavor

We need to take a moment to praise Armenian food culture because—wow. The way this country celebrates flavor is just incredible. The bartenders, chefs, and producers we met weren’t just talented—they were generous, curious, and innovative in their craft.

Huge thanks to:

• Gegam Kazarian, the visionary founder of Yerevan Cocktail Week, for creating something truly special. (And for foraging the local pine needles that went into the most delicious fermented pine needle soda I’ve ever tasted—fermented by the wizard Pavel Barkov)

• Tigran Avetisyan and the whole Bar Phoenīx crew—you made us feel right at home, and chef Arman Ghonaghchyan was an absolute legend in helping us prep for the workshop.

• The team at Blue Gold Bar for hosting my guest shift, where I got to mix cocktails some ferments like kvass, bubble gum water kefir, and that unforgettable pine needle soda.

This festival was a massive success, not just because of the drinks and events, but because of the people behind them. Armenia’s bar and food scene is on fire right now, and I can’t wait to see where it goes next.

To everyone who came out, asked questions, shared a drink, or just geeked out over fermentation with us—thank you. You made this one of the most memorable trips of my career. Until next time, keep those ferments bubbling and those cocktails shaking!

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If you’d like to get the recipes we tought at the “Fermentation in Desserts” masterclass - just click the link below and download our FREE guide:

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In a world where industrial sodas dominate with artificial flavors and excessive sugar, fermentation offers a revolutionary alternative—one that is alive, probiotic-rich, and bursting with complex flavors. Our upcoming Lacto-Fermented Sodas Workshop on July 6 in Dubai is not just a culinary experience; it’s a deep dive into the microbial alchemy that turns overlooked ingredients into effervescent, health-boosting beverages while unlocking endless possibilities for flavor innovation and cost efficiency.

The Science Behind Fermented Sodas

Fermentation, one of humanity's oldest food preservation methods, harnesses the power of microorganisms to transform sugars into acids while unlocking bold new flavors. In the case of lacto-fermented sodas, we rely primarily on lactic acid bacteria (LAB), yeasts, and other beneficial microbes to create natural carbonation and tangy, probiotic-rich drinks.

1. Ginger Bug Sodas: Wild Fermentation at Work

A ginger bug is a natural starter culture made from ginger, sugar, and water. The ginger’s wild yeasts (such as Saccharomyces species) and LAB (Lactobacillus) consume the sugar, producing CO₂ and organic acids (like lactic and acetic acid). This creates a naturally fizzy, non-alcoholic soda base that can be flavored with fruits, herbs, and spices.

Unlike commercial sodas, which rely on forced carbonation, ginger bug fermentation develops complex flavor profiles over time, with subtle spicy, sour, and funky notes. The plain ginger bug soda is your real non-alcohoic Ginger Beer.

2. Water Kefir: A Probiotic Powerhouse

Water kefir grains (a symbiotic culture of bacteria and yeast, or SCOBY) metabolize sugar in water, producing a lightly effervescent, probiotic-rich drink. The dominant microbes—Lactobacillus, Leuconostoc, and Acetobacter—generate lactic and acetic acids while yeasts like Saccharomyces contribute to carbonation.

The result? A gut-friendly, low-sugar soda alternative that supports digestion and immunity—far removed from the empty calories of conventional soft drinks. The secondary fermentation with fruits makes wonders here.

3. Lacto-Fermented Amazake Sodas: Enzymatic & Microbial Magic

Amazake, a traditional Japanese sweet rice drink, is made by transforming rice with Aspergillus oryzae (koji mold), which breaks down starches into simple sugars and proteins into amino acids, unlocking sweet and umami tastes. When combined with LAB these sugars undergo a secondary fermentation, producing a lightly sour, effervescent soda with umami depth.

This dual-fermentation process (enzymatic + lactic) creates a uniquely layered beverage, showcasing how traditional techniques can be reinvented for modern palates. No sugar added!

4. Modern Kvass: Reinventing Tradition

Kvass, a Slavic fermented drink traditionally made from rye bread, undergoes lactic acid and yeast fermentation, resulting in a tangy thirst-quenching brew. Our modern take might incorporate fruits, spices, or herbs, leveraging wild fermentation for a more dynamic flavor.

The microbes in kvass—primarily Lactobacillus and wild yeasts—enhance bioavailability of nutrients and add a refreshing tartness, making it a nutritious alternative to sugary sodas.

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Why This Workshop Matters

Industrial sodas contribute to plastic waste, excessive sugar consumption, and a disconnect from real food. By learning lacto-fermentation techniques, participants not only reduce food waste (using surplus fruits, herbs, and grains) but also craft living beverages that support gut health.

This workshop is for:

• Food innovators seeking sustainable alternatives

• Health-conscious individuals exploring probiotic-rich drinks

• Culinary professionals pushing flavor boundaries

Limited to 10 participants—secure your spot and redefine what soda can be!

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Amazake, a traditional Japanese sweet rice drink, is made by fermenting rice with koji (Aspergillus oryzae). The enzymes in koji break down rice starches into simple sugars, creating a naturally sweet, nutrient-rich liquid. By fermenting this liquid with water kefir grains or ginger bug, we transform it into a fizzy, probiotic-rich soda—without any added sugar.

Unlike commercial sodas or even kombucha, this method leverages koji’s enzymatic power to provide all the sugar needed for fermentation. The result is a well-balanced, tangy drink with a deep umami aftertaste—a signature of koji fermentation.

The Science Behind Amazake Soda Fermentation

This process combines two key microbial actions:

1. Enzymatic Sugar Release (Amazake Stage)

   • Koji’s enzymes (amylase, glucoamylase) break down rice starches into glucose and maltose.

   • Incubate at 50–60°C for 8–10 hours (sous vide recommended for precision).

   • The strained liquid is diluted to 8–10°Bx, ideal for LAB fermentation.

2. Lactic Acid Fermentation (Soda Stage)

   • Water kefir grains or ginger bug introduce LAB (Lactobacillus) and wild yeast.

   • Fermenting at 20–24°C for 3–4 days ensures a robust LAB profile.

   • Final pH drops to 3.5–4.0, delivering a bright acidity and lingering umami depth.

Key Benefits of This Method

✔ No added sugar – Koji enzymes provide all fermentable sugars naturally.
✔ Rich umami complexity – Koji’s proteolytic activity enhances flavor depth.
✔ LAB-dominant – Promotes gut-friendly bacteria over excessive yeast.
✔ Customizable – Fruits/herbs can be added for secondary fermentation.

Note on Water Kefir Grains Maintenance

Water kefir grains require sugar to thrive. After each amazake soda batch, rejuvenate them in a 8% sugar-water solution for 24–48 hours before reuse.

Recipe: Lacto-Fermented Amazake Soda

Ingredients

Amazake Base:

• 500 g rice koji (Aspergillus oryzae-inoculated rice)

• 750 g water or tea (lightly brewed tea or herbal infusion)

Fermentation Starter:

• 1 tbsp active water kefir grains (or 50 ml ginger bug liquid)

Optional for Secondary Fermentation:

• 100 g fruit or puree and/or herbs

Equipment

• Sous vide setup (or warm fermentation chamber – a rice cooker at “Keep Warm” mode)

• Cheesecloth/fine strainer

• Fermentation jar

• Refractometer (for °Bx)

• pH strips/meter

Method

1. Prepare the Amazake Liquid

• Mix rice koji and water/herbal tea in a sous vide bag or jar.

• Incubate at 55°C for 8–10 hours.

• Strain through cheesecloth, pressing to extract all liquid. Discard solids.

• Dilute with water to 8–10°Bx (measure with brix refractometer).

2. Primary Fermentation (Culturing with LAB)

• Combine strained amazake liquid and water kefir grains / ginger bug liquid in a clean jar.

• Cover with a breathable cloth or loose lid.

• Ferment at 22–25°C for 2 days (if using water kefir grains, strain them out after 48 hours)

• Transfer into a sealed bottle and at 20–24°C for 2 more days for carbonation.

• Check pH: Target 3.5–4.0 (tangy and umami-rich).

3. Secondary Fermentation – Optional (Flavor & Carbonation)

• Add fruit/herbs if desired.

• Leave 5cm headspace and seal tightly.

• Ferment at 20–24°C for 2 days, then cold-crash in fridge for 24 hours.

4. Serving & Storage

• Chill before opening to retain carbonation.

• Store refrigerated for up to 3 weeks.

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Troubleshooting Tips

• Weak acidity? Extend fermentation by 1 day.

• Overly fizzy? Reduce secondary fermentation time.

Why This Soda Stands Out

Amazake soda is not just another probiotic drink—it’s a harmony of science and tradition. The koji-driven process ensures a perfect balance of sweetness, acidity, and umami, while LAB fermentation adds gut-health benefits.

Ready to experiment? Share your results with us at info@cosmos-society.com or tag us on Instagram @cosmos.society.concepts and explore more koji-based fermentations!

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Another amazake-based LAB-driven fermentation:

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Denis Pashkov
cosmos society