How to Make Hard Kombucha: A Simple, Step-by-Step Guide

Hard kombucha is a popular fermented beverage that has gained traction in recent years due to its unique flavor profile and potential health benefits. As a variation of traditional kombucha, which is made by fermenting sweetened tea with a symbiotic culture of bacteria and yeast (SCOBY), hard kombucha undergoes an additional fermentation process that increases the alcohol content while maintaining its characteristic tangy taste. 

This beverage appeals to those who are looking for a healthier alternative to traditional alcoholic beverages and appreciate the unique flavors of kombucha.

The process of making hard kombucha involves two consecutive fermentation stages. First, the basic kombucha is made by brewing tea, adding sugar, and introducing a SCOBY to the mixture, allowing it to ferment for about 7 to 10 days. 

This initial fermentation results in a lightly fizzy, probiotic-rich beverage with a low alcohol content. In the second fermentation, additional sugar and yeast are added to the kombucha, which is then left to ferment for an extended period, typically ranging from a couple of weeks to a month. This second fermentation allows the kombucha to develop a higher alcohol content, transforming it into hard kombucha.

The versatile nature of hard kombucha allows for various combinations of tea types, sugars, and flavorings to be used in its production, offering an array of flavors and nuances to suit individual preferences. Green tea, black tea, and other tea varieties can be used as a base, while organic honey, sugar, or other sweeteners serve as fuel for fermentation. 

The addition of fruits, herbs, and spices during the second fermentation step allows for endless customization and experimentation, making hard kombucha a beverage with an ever-evolving flavor palette.

Basics of Hard Kombucha

What Makes It Hard

Hard kombucha is a fermented tea beverage that contains a small amount of alcohol, typically ranging between 1.5% and 8% alcohol by volume (ABV). The alcohol content in hard kombucha is primarily due to the presence of ethanol, which is a natural byproduct of the fermentation process. 

During this process, the yeast consumes sugar and produces ethanol and carbon dioxide, giving kombucha its characteristic fizzy nature and slight alcoholic content. To create hard kombucha, additional sugar and yeast are introduced, allowing for an extended fermentation and higher alcohol content.

Difference from Regular Kombucha

While both hard kombucha and regular kombucha involve the fermentation of sweetened tea using a symbiotic culture of bacteria and yeast (SCOBY), there are a few key differences between the two:

1. Alcohol content: The primary distinguishing factor between hard kombucha and regular kombucha is the alcohol content. As mentioned earlier, hard kombucha has a higher alcohol content, whereas regular kombucha typically contains less than 0.5% ABV.

2. Fermentation process: The fermentation process for hard kombucha may involve an additional fermentation stage to boost the alcohol content. In this stage, increased sugar and a specific yeast strain are introduced to facilitate higher ethanol production.

3. Flavor profile: Due to the extended fermentation and higher alcohol content, hard kombucha typically has a more complex and robust flavor profile compared to regular kombucha. It may also be infused with various fruits, herbs, and other flavorings to create unique and diverse taste combinations.

Ingredients Needed to Make Hard Kombucha

Choice of Tea

When making hard kombucha, the choice of tea plays a crucial role in determining the overall flavor of your brew. Some popular options include:

– Black tea: Offers a strong, bold flavor and works well as a base for hard kombucha.

– Green tea: Provides a lighter taste and can create a more delicate hard kombucha.

– Oolong tea: Works as a midway option between black and green tea, contributing a balanced and nuanced flavor profile.

Feel free to experiment with various teas to create your unique hard kombucha.


While various sweeteners can be used in kombucha brewing, choosing an appropriate one that allows proper fermentation is essential.

Some commonly used sweeteners include:

– Table sugar: A popular and easily accessible choice, promotes efficient fermentation.

– Honey: Can be used for additional flavors and natural sweetness, but might require adjustments in the brewing process.

It’s best to avoid alternative sugars like agave and coconut sugar as they can be difficult to work with and may negatively affect fermentation.


SCOBY (Symbiotic Culture of Bacteria and Yeast) is a vital element in producing hard kombucha. It’s a living culture that converts sugar into alcohol and carbon dioxide, thus fermenting the tea. Be sure to use a fully hydrated, active SCOBY to ensure successful fermentation and flavor development.

Starter Kombucha

Starter kombucha is an essential component in making hard kombucha as it helps kickstart the fermentation process. The starter kombucha should be unpasteurized and unflavored, as this will provide the right balance of bacteria and yeast to enable proper fermentation.

First Fermentation Process

Preparing Sweet Tea

The first step in making hard kombucha is the first fermentation process to produce regular kombucha. Start by preparing sweet tea. Bring water to a boil, remove it from heat, and dissolve sugar into the hot water. Add tea bags and allow them to steep for at least 20 minutes or until the tea has cooled to room temperature.

Adding Starter Kombucha and SCOBY

Once the sweet tea has cooled, transfer it to a clean and sterilized fermentation container. Add the starter kombucha, which helps to kickstart the fermentation process due to its existing culture of bacteria and yeast. Next, gently place the SCOBY (Symbiotic Culture Of Bacteria and Yeast) on top of the liquid. The SCOBY plays a crucial role in fermentation, converting sugar into alcohol and acetic acid.

Fermentation Conditions

Cover the container with a breathable cloth, such as cheesecloth, to ensure proper fermentation and secure it with a rubber band. This cover allows air circulation while keeping contaminants out of the brew. Store the container in a dark, cool, and well-ventilated area with a consistent room temperature of around 68°F to 78°F (20°C-25°C). Keep the container away from direct sunlight and avoid disturbing it during fermentation.

Checking Fermentation Progress

The first fermentation typically takes 7-12 days. Regularly check the kombucha’s progress, and observe any changes in the appearance or aroma. You can test the kombucha by placing a clean straw under the SCOBY and sipping a small amount. It should have a slightly tangy and tart taste. When the kombucha reaches the desired taste, remove the SCOBY and proceed to the next step.

By following these steps, the first fermentation process will create a base kombucha that can be further processed to make hard kombucha.

Adding Alcohol in Second Fermentation

Yeast Selection

Selecting the correct yeast is crucial for increasing the alcohol content in the second fermentation of hard kombucha. Several types of yeast can work well, including:

– Ale Yeast: For example, Safale US-05, a common and versatile choice.

– Wine Yeast: Provides a wine-like, fruity character to the kombucha.

– Champagne Yeast: Imparts a higher tolerance for alcohol and produces a cleaner flavor.

Calculating ABV and Sugar Requirements

To calculate the desired alcohol by volume (ABV) and sugar requirements for the second fermentation, follow these steps:

1. Determine the target ABV for your hard kombucha (for example, 6%).

2. Calculate the difference between the original kombucha’s ABV (typically around 0.5% to 1%) and the target ABV (in this case, 5% – 1% = 4%).

3. Calculate the sugar required to achieve this difference using the formula: sugar (grams) = (desired ABV increase %) x 19 x volume (liters)

For example, if you have a 4-liter batch and want to increase the ABV by 4%, you’ll need:

Sugar (g) = 4% x 19 x 4L = 304 grams of sugar (use dextrose for a more accurate calculation)

Introducing Yeast and Sugar

After selecting the appropriate yeast and calculating the required sugar, you can now proceed with introducing them into the second fermentation process:

1. Create a yeast slurry by dissolving the calculated sugar (dextrose) in 1 cup of hot water, and then adding the chosen yeast.

2. Allow the yeast slurry to cool down to room temperature (around 70℉ to 75℉).

3. Add the yeast slurry to your gallon of kombucha from the first fermentation.

4. Mix gently to incorporate the yeast and sugar into the kombucha.

5. Seal the airtight kombucha containers and store them in a dark room at a controlled temperature (70℉ to 75℉) for the second fermentation.

The second fermentation process will take approximately 3 to 5 days, depending on temperature and yeast activity. The yeast will consume the added sugar during this time, producing alcohol and carbon dioxide. This will increase the ABV of your kombucha, creating a fizzy, boozy beverage.

Flavoring and Carbonation

Adding Flavoring Elements

When making hard kombucha, there are various ingredients one can use to add flavor. It’s essential to experiment with different flavors and sources, such as:

– Tea: Using different tea varieties like green tea, black tea, and oolong tea can significantly impact the flavor profile.

– Fruits: Fresh fruits, purees, or juices like lemon, berries, or mango can be added for a natural and unique taste.

– Herbs and Spices: Flavorings from herbs like mint, basil, or spices like ginger, cinnamon, or cardamom can create more complex flavors.

Mix and match these ingredients to develop your personalized kombucha recipes.

Carbonating During Second Fermentation

To achieve carbonation in hard kombucha, a second fermentation process is required. Here’s a brief guide on carbonating during the second fermentation:

1. After the first fermentation is complete, transfer the kombucha to airtight bottles.

2. Add around 1/2 – 1 teaspoon of plain sugar to each bottle. The sugar will supply the yeast with food to convert into carbon dioxide.

3. Seal the bottles tightly to trap the gas produced during fermentation.

4. Allow the kombucha to ferment for an additional 2-7 days to build carbonation.

Remember that temperature affects fermentation, so a warmer environment may result in a faster second fermentation, while a cooler one may slow it down.

Using Airlock and Hydrometer

Monitoring the fermentation process is crucial to ensure a safe and enjoyable beverage when making hard kombucha. An airlock during fermentation can help prevent contamination from undesirable bacteria or wild yeasts.

The airlock allows the release of carbon dioxide while preventing air from entering the fermenting vessel. This creates a more controlled fermentation process.

A hydrometer is essential for measuring the kombucha’s specific gravity during fermentation. This measurement can help determine the amount of alcohol and sugar present in the beverage, ensuring the desired level of fermentation is reached.

To use a hydrometer, follow these steps:

1. Take a sample of your fermenting kombucha in a sanitized test jar or container.

2. Float the hydrometer in the sample and take the reading at the liquid’s surface.

3. Compare the measurements at different stages of the fermentation to determine the progress.

By utilizing these tools and techniques for flavoring and carbonation, you can achieve the desired taste and fizziness in your hard kombucha.

Bottling and Storage

Preparing for Bottling

When bottling hard kombucha, it is important to have the right equipment and to follow proper sanitization procedures. Here are the necessary steps:

1. Gather necessary supplies: airtight glass bottles (swing-top bottles work well), a funnel, a pitcher, and clean kitchen towels.

2. Sanitize all equipment, including bottles, funnel, and pitcher, to prevent contamination.

3. Transfer the kombucha from the brewing vessel to a pitcher using a clean hand or a sanitized utensil.

4. Use the funnel to pour the kombucha into the glass bottles. Leave about 1 inch of headspace at the top for carbonation.

Monitoring Carbonation Levels

Carbonation is a key element for creating the fizzy texture in hard kombucha. When bottling, it is essential to monitor the carbonation levels in the kombucha to ensure proper carbonation without risking over carbonation or bottle explosions.

Here are some tips for tracking the carbonation:

1. Store the bottles at room temperature for 1 to 3 days to carbonate. Warmer temperatures and higher sugar content will accelerate the process.

2. Periodically check the carbonation by gently squeezing the bottle. If the bottle feels firm, open it to release some CO2 pressure and then reseal it to avoid over carbonation.

3. Optionally, you can use a plastic bottle as a test bottle. Fill the plastic bottle with kombucha, and when the bottle feels firm, you know your glass bottles are sufficiently carbonated.

Storing Bottles Properly

Proper storage is crucial for hard kombucha to maintain its flavor and quality over time. Follow these guidelines for optimal storage:

1. After the carbonation process is complete, store the bottles in a refrigerator. This will slow down fermentation and maintain kombucha’s taste and carbonation.

2. Keep bottles away from direct sunlight, as exposure to light can affect the quality and flavor of the kombucha.

3. Store bottles in an upright position to minimize the risk of leaks and prevent sediment from collecting in the neck of the bottle.

Troubleshooting and Tips

Common Issues

1. Yeasty smell in Kombucha

To reduce the yeasty smell in kombucha, simply lower the temperature of the brew to below 74ºF (68-70 should be perfect). This will reduce the growth of yeast cells. Alternatively, one can filter the brew with a coffee filter and take it through a second ferment.

2. Inconsistent alcohol content

The alcohol content of hard kombucha can vary depending on factors like the fermentation time and temperature. To ensure a consistent alcohol content, maintain a constant temperature between 70-73ºF and follow the recommended fermentation times: 6 to 10 days for the first fermentation and 7 to 14 days for the second fermentation.

Improving Flavor

One can experiment with different amounts of priming sugar during the second fermentation for a better flavor. Adding various fruits or herbs can also enhance the taste of hard kombucha. When adding flavors, use only 10% to 20% per bottle during the optional third fermentation (3 to 10 days) to prevent overpowering the natural kombucha taste.


To increase carbonation in the final product, follow these steps:

1. Transfer the kombucha to airtight bottles (swing-top bottles work well) to make it fizzy. Leave only about 1 inch or less difference between the mouth of the bottle and the surface of the kombucha.

2. If carbonation is still lacking, add a small amount of sugar during the third fermentation (optional) to help produce more CO2.

P.S. If you want to brew your own beer, grab your gift of Big Robb’s top 5 favorite beer recipes from his brewpub; details are on the side of the blog or at the bottom if you are on your phone.  Enjoy!

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