Second Fermention Kombucha: The Complete Guide

What Is A Second Ferment?

Second fermentation is the process of flavoring raw kombucha by infusing flavoring ingredients in an anaerobic environment (sealed bottles). The brew needs to be sealed in airtight bottles to trap the carbon dioxide produced, brew making it fizzier.

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• Is The Second Fermentation Necessary For Kombucha?

• What Is A ‘First Ferment’?

• 6 Ways To Influence The Taste Of Kombucha

• Common Second Ferment Questions

• Fruity Second Ferment Recipes

• Best Bottles For Kombucha Second Fermentation

• Kombucha Second Fermentation And Mold

• Other FAQs

Is The Second Fermentation Necessary For Kombucha?

The simple answer is no; raw kombucha can be consumed after the first ferment without any problems. However, if you are having a hard time adapting to the taste of raw kombucha or would like to add flavors, then a second ferment will be in order.

What Is A ‘First Ferment’?

The first ferment refers to the initial fermentation of fermented tea. The ingredients are added (SCOBY, Starter Tea, Sugar, Tea, Water) before being left to brew. The starter tea serves to introduce an acidic environment in the brew it also increases the population of yeast and bacteria culture.

The raw ingredients required in the first ferment such as tea leaves and a source of sugar usually play a major role in determining the flavor of the final brew. As a result, using a different tea variety or sugar source will reflect a change in the taste of the raw kombucha which is used in the second ferment. 

6 Ways To Influence The Taste Of Kombucha

The taste of the final brew which has undergone a second ferment can be adjusted by tweaking some basic factors in the process. These include carbonation, adding ingredients and changing the temperature of the brew during fermentation.

The second fermentation process incorporates the kombucha from the first ferment. Meaning the taste of your first ferment will strongly influence the taste of the second. Factors from the first ferment could include the type of tea, length of fermentation and pH balance.

Type Of Tea Used - Tea varieties used in the first ferment produce varying tastes which are retained in the final brew.

Additional Flavoring Ingredients - While kombucha requires only freshly brewed and sweetened tea as the primary ingredient, some recipes can include additional ingredients. These are bound to influence the final taste of the brew as their taste notes get infused into it during the fermentation process. 

Adding a secondary flavoring ingredient during the second ferment will also drastically influence the final taste of your kombucha. The most common flavoring ingredients in the second ferment are fruits (blood oranges, blackberries, lemons etc), spices (mint, lavender, ginger, cinnamon etc) and juice blends (cherries and almonds, pineapple and coconut, pears and almonds etc).

Sweetness - The sweetness in kombucha is the remaining sugar in the brew after the fermentation process. A short fermentation period results in a sweet brew, while a prolonged brewing period allows the bacteria to break down most of the dissolved sugar.

The sweetness of the kombucha drink can be adjusted by introducing a sweet flavor during the second ferment, such as fruits and juices.

It's important to note that not all sweet ingredients are actually sugar. It's possible to have a delicious drink but with low sugar content, using ingredients such as stevia. 

Disclaimer: We would recommend researching stevia and to avoid the artificial kind. For more information take a look here.Ref: NCBI.

Tartness - The tartness of kombucha is a result of the production of acetic acid by the culture. This gives the drink an acidic pH and a noticeable tartness similar to vinegar. How tart the drink gets will be determined by the length of the fermentation period and the amount of sugar in the initial tea.The longer the fermentation period the more tart the final brew will be.

Alcohol - The alcohol content in a brew gets quite noticeable, with each percentage increase. The alcohol content in kombucha is as a result of the ethanol produced by the yeast culture as it breaks down the dissolved sugar. Which could result in an ABV of up to 5%.

Time - The kombucha fermentation process takes around 7 to 14 days in order to develop the most optimal taste. If the fermentation process gets cut off any earlier, then you will be left with a weak tasting brew. If allowed to continue for an extended period the brew will become more tart and sour.

Carbonation - The carbonation process in kombucha results in not only a more effervescent drink but also a better-tasting brew. Naturally, carbonated kombucha is finer and much smoother on the tongue as there’s a natural balance of carbon in the brew.

In order to naturally carbonate kombucha, a second ferment is required. During this process, a small amount of sugar may be added to increase the amount of carbon produced by the yeast and bacteria culture as it breaks down the additional sugar content.

Temperature - Temperature plays a vital role in the fermentation process and as a result, it usually influences the taste of kombucha. The low temperature could gradually slow down the fermentation process leading to a weak tasting brew. If too hot it can also ruin the batch too. Keep within the critical range 68-78°F (20-25°C). 

Common Second Ferment Questions

How Long To Second Ferment Kombucha For?

The second ferment usually takes 3 to 5 days to ferment. The ferment is shorter because the yeast and bacteria culture are already developed from the raw kombucha. This results in quick carbon dioxide accumulation, and ferment. 

Can Kombucha Ferment For Too Long?

Yes kombucha can ferment for too long. When left to ferment for too long, kombucha will become too vinegary to consume. There is a build up of acetic acid, which reduces the pH making it unsuitable to drink. Such kombucha can be used as a cleaning agent due to its acidic and antibacterial properties.

How Do You Make A Second Ferment Carbonated?

Adding two tablespoons of white sugar per 16 oz of raw kombucha will increase the amount of carbon dioxide produced by the culture. The raw kombucha is then mixed with the flavoring ingredient and sealed in thick-walled airtight bottles. After 3 to 5 days, the flavored brew will have naturally accumulated enough carbon dioxide to make it fizzy.

Fruity Second Ferment Recipes 

Hibiscus kombucha

Inspired by The Organic Goatlady, this recipe is great and we would recommend checking them out for more information: The Organic Lady

Ingredients

•         4 tsp. dried hibiscus petals

•         1 tbsp. freshly squeezed lemon juice

•         16 oz raw kombucha

Instructions

• Measure out the kombucha into the glass bottle and add the dried hibiscus petals and freshly squeezed lemon juice

• Reseal the bottle and ensure its airtight, give it a gentle shake and transfer it to the fermentation area.

• Allow the brew to ferment for three days before transferring to the refrigerator for storage

Ginger Kombucha

Inspired by Fermentation Recipes, for more information, check out their website: Fermentation Recipes!

Ingredients

• 1 teaspoon Freshly cut ginger

• ¼ tsp turmeric powder

• 16 oz raw kombucha

Instructions

• Use a funnel to pour the raw kombucha into a glass bottle

• Add the turmeric powder and freshly cut ginger and give the bottle a gentle shake

• Seal the bottle and move to the fermentation area. Allow the brew to ferment for 3 to 5 days

Lemon & Ginger Kombucha

Inspired by Live Eat Learn, to see more click here: Lie Eat Learn

Ingredients

• ½ gallon raw kombucha

• 2 lemons

• 2 tsp white sugar

• 1 thumb freshly grated ginger

Instructions

• In a large glass bowl, add the juiced lemons, white sugar and freshly grated ginger. Mix thoroughly

• Gently pour the kombucha into the glass bowl and use a wooden spatula to mix it with the flavoring ingredients gently

•  Use a funnel to fill the fermentation bottles with the mixed kombucha gently

•  Seal the bottles airtight and transfer to the formation area for 3 to 5-day second ferment

Turmeric Kombucha

Inspired by All the Nourishing Things, you can check them out here: All The Nourishing Things.

Ingredients

• 16 oz raw kombucha

• 1 tablespoon ginger, freshly chopped

• 1 tablespoon turmeric root, freshly chopped

• 2 tablespoons white sugar

Instructions

• Add the ginger, turmeric root, and white sugar into the fermentation bottle

• Gently pour in the kombucha all the way to about 2 inches from the top

• Seal the bottle and move it to the fermentation area away from direct sunlight. Allow the brew to ferment for 3 to 6 days, depending on your taste preferences.

Blackberry Vanilla Kombucha

Inspired by Brewbuch, we would recommend checking them out for more information: Brew Bunch.

Ingredients

• ½ gallon raw kombucha

• ½ cup blackberries

• 10 g white sugar

• ½ teaspoon vanilla

• ¼ cup water, unchlorinated

Instructions

• Add the water, blackberries, and sugar in a saucepan and bring to boil over medium heat. Mash the berries until a thick paste is formed. Allow the paste to cool down to room temperature

• Evenly distribute the paste and vanilla into the fermentation bottles and gently pour in the raw kombucha

• Seal the bottles and transfer them to the fermentation area for the next 3 to 5 days

Blood Orange-Flavored Kombucha

Inspired by Kombuchakamp, this recipe is great and we would recommend checking them out for more information: Kombucha Kamp.

Ingredients

• ½ blood orange, juiced

• ½ teaspoon of ginger

• ½ teaspoon clove

• 16 oz raw kombucha

Instructions

• Add the blood orange juice, ginger, clove, and raw kombucha into the fermentation bottle and give it a gentle shake

• Seal the bottle airtight and transfer it to a dark area away from direct sunlight and allow it to ferment for the next 3 to 5 days

Raspberry Lime-Flavored Kombucha

Inspired by Paleo Running Momma, this recipe is great and we would recommend checking them out for more information: Paleo Running Momma.

Ingredients

• 1-gallon raw kombucha

• 2/3 cup raspberries, freshly chopped

• ¼ cup lime juice, freshly squeezed

Instructions

• Mix the raw kombucha, raspberries and lime juice in a glass bowl

• Pour out the mixture into the fermentation bottles leaving 2 inches of headspace in each

• Replace the lid and transfer the bottles to the fermentation area for the next 3 to 5 days

Watermelon Kombucha

Inspired by Bucha Brewers, this recipe is great and we would recommend checking them out for more information: Bucha Brewers.

Ingredients

• ¼ cup of watermelon slices/juice

• 4 sliced blackberries

• 14 oz raw kombucha

Instructions

• Use a funnel to add the watermelon juice, blackberries, and raw kombucha into the fermentation bottle

• Seal the bottle and give it a gentle shake before moving it to the fermentation area

• Allow the brew to ferment for 3 to 5 days before moving it to the fridge for storage

Peach Flavored Kombucha

Inspired by Live Eat Learn, this recipe is great and we would recommend checking them out for more information: Live Eat Learn.

Ingredients

• ½ gallon raw kombucha

• 1 ripe peach, finely diced

• 2 tablespoons maple syrup

• ½ teaspoon vanilla extract

Instructions

• Evenly divide the raw kombucha, finely diced peach, maple syrup, and vanilla extract amongst the fermentation bottles

• Seal the bottles and give them a gentle shake to mix up the ingredients before moving them to the fermentation area

• Allow the brew to ferment for 3 to 10 days depending on your taste preference

Apple Cinnamon Kombucha

Inspired by Live Eat Learn, this recipe is great and we would recommend checking them out for more information: Live Eat Learn.

Ingredients

• ½ gallon raw kombucha

• 1 apple, finely diced

• ½ teaspoon ground cinnamon

Instructions

• Mix the raw kombucha, finely diced apple, and cinnamon in a glass bowl using a wooden spoon to stir gently

• Pour mixture into the fermentation bottles leaving a 2-inch headspace in each

• Seal the bottles and transfer them to a dark area within room temperature.

• Allow the brew to ferment for the next 3 to 10 days or until it attains the required carbonation level

Best Bottles For Kombucha Second Fermentation

For our complete guide to all of the types of kombucha bottles and what to look for when picking click on our guide. Below is a short summarisation of our findings. 

Flip-Top Bottles

Flip-top bottles are designed with a swing cap on the flip-top making it much easier to make an airtight seal. These bottles have thick glass walls that can withstand internal pressure, no messy explosions!

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Wine Bottles

Flat bottomed wine bottles hold well against the extra pressure caused by carbon dioxide accumulation in the brew. You can either recycle wine bottles that you may have lying around or you can buy them in bulk. Ensure that the bottles are equipped with fitting natural corks that can maintain an airtight seal.

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Bottling Process

Equipment Required

• Thick-walled glass bottles equipped with fitting lids

• Funnel

Ingredients required

• Raw kombucha

• Flavoring ingredient, washed and cut/diced accordingly

• 1/2 tsp white sugar per 16 oz of kombucha

Instructions

• Add the flavoring ingredients to each bottle and add the white sugar

• Use a funnel to gently pour in raw kombucha and fill the bottles leaving a 2-inch headspace which will serve to hold the excess carbon dioxide produced while also preventing spillage

• Use the lids to seal the bottles airtight and give them a gentle shake until the sugar gets dissolve completely

• Transfer the bottles to the fermentation area which should be away from direct sunlight and within room temperature

• Burp the bottles on a daily basis and allow the kombucha to ferment for 3 to 5 days.

For a more comprehensive guide to kombucha brewing vessels click on our complete guide. Included is all types of brewing vessels, materials and considerations ensuring you pick the right one for you.

Kombucha Second Fermentation And Mold

While it's not common, mold can grow during the second ferment if the bottles are not sealed correctly or as a result of contamination. This results in clumps of fuzzy black/greyish mold growing on the upper surface of the flavored kombucha. Moldy kombucha should be disposed of and the bottles disinfected with concentrated vinegar to prevent future contamination.

Always ensure that the second fermentation bottles are sealed airtight to prevent oxygen from getting in and carbon dioxide from escaping.

Other FAQs

Why Is My Kombucha Not Fizzy?

This is as a result of a lack of carbonation; this could happen when the kombucha gets shaken too much, if this is the case you should second ferment the kombucha with 2 tablespoons of white sugar to increase carbonation. 

Kombucha can also lose its fizziness If it has been sitting for too long and most of the carbon dioxide has escaped especially if it was not stored in airtight bottles.

If the brew gets contaminated the bacteria and yeast culture population will drastically reduce leading to a flat brew. Use a pH strip to test the acidity of the brew to determine if its contaminated, if the pH reading is above 4 then the brew should be disposed. 

Does Kombucha Continue To Ferment During The Second Ferment?

Yes, the culture continues to ferment the brew during the second ferment breaking any remaining sugar to produce carbon dioxide 

Should I Burp My Bottles?

Yes you can do, burping the bottles on a daily basis is recommended by some brewers.

Can You Second Ferment Kombucha In Plastic Bottles?

It’s not recommended to use plastic bottles as the excess pressure usually makes them to swell and harden. The acidic pH of kombucha can also degrade the plastic as well as dissolve microplastics which are harmful if consumed. As the last option, you can use food-grade plastic bottles but only ones and recycle them afterward. 

Interested in learning more about kombucha? 
Check out these articles:

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Does Kombucha Go Bad?

Is Kombucha Acidic

How Much Caffeine Is In Kombucha?

Kombucha Side Effects