Homemade Kombucha: A Fizzy Fermented Beverage

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You can’t talk about fun homemade fermentation projects without giving kombucha at least an honorable mention!

More than just a silly fad or passing trend, kombucha and its characteristically sweet-and-sour taste is here to stay.

This fizzy, fermented beverage already holds prime real estate at many grocery stores – you might stroll past a large refrigerated wall dedicated to showcasing different brands, with a brilliant rainbow of colors and flavors shining bright underneath the fluorescent lights.

While you can pay for the convenience of plopping a few bottles in your cart, I challenge you to brew this refreshing carbonated drink completely from scratch.

Creating homemade kombucha is a realistic project to undertake when you’re craving a new at-home culinary experiment that caters to your individual taste preferences and creativity.

And unlike babysitting and meticulously tending to a sourdough starter, preparing homemade kombucha is a far more forgiving, playful, and laidback process.

But you do still need to understand and follow the proper fermenting techniques for safe and successful final results.

So, let’s chat about kombucha! What is it exactly, and how do you make it?

I’ll provide a brief explanation to begin, but you’ll find a more in-depth discussion in the detailed Cooking by the Numbers section below – so keep reading!

Here’s a quick preview of everything to come, up ahead:

What Is Kombucha?

Kombucha is a fermented sweet tea drink made with a simple combination of plain water, tea leaves, granulated sugar, and assorted flavorings.

The carbonation level is controlled by two separate stages of fermentation at room temperature.

The natural yeasts, bacteria, and sugar combined in the liquid form a safe environment for natural fermentation to occur, creating a carbonated beverage with potential probiotic benefits.

How Do You Make It?

The first step of making kombucha is to brew a large batch of tea. Once brewed, you then sweeten it with sugar and allow this liquid to ferment at room temperature.

For the strongest and most successful fermentation, unflavored organic black tea is often used, but there can be variations depending on the recipe you choose to use.

Similar to making sourdough bread, in which every batch of dough relies upon a mother or starter from a previous batch, making kombucha requires a few additional ingredients to catalyze fermentation.

First Fermentation

In order to jumpstart the first fermentation, which may last anywhere from one to three weeks, the freshly brewed tea depends on the addition of two important ingredients: a starter tea and a SCOBY.

Starter Tea

The starter tea is often a previously made plain kombucha base that has gone through the first fermentation successfully. It has no added flavors, and has not gone through a second fermentation.

However, you can also use a plain, unflavored store-bought kombucha in a pinch, especially if this is your first time brewing and you don’t have any starter tea on hand.

SCOBY

SCOBY is an acronym that stands for “Symbiotic Culture Of Bacteria And Yeast.” It may also be referred to as a kombucha culture.

You add one to start, and these solid, gelatinous discs naturally form and float on the surface of the liquid each time you make a new batch of kombucha. They contain healthy cultures of bacteria and yeast.

They will take the shape of the container in which you brew the kombucha.

A healthy SCOBY will usually start out light cream or tan in color, and it will darken over time.

A darker color and thin, limp texture are clear indicators that your SCOBY is past its prime. If you notice these signs, or after you have used the same SCOBY for 2 to 3 different rounds of making kombucha, you can dispose of it.

Don’t worry – you’ll have plenty of fresh SCOBY after making each new kombucha recipe!

Second Fermentation

The second fermentation occurs after you have flavored, bottled, and sealed your  kombucha in smaller containers to hold individual servings.

The flavors you use are completely up to your personal taste preferences. Ideally, you would use a liquid option for the flavoring component, such as a fruit or sugar syrup, juice, or puree.

With this additional sugar, the microbes in the kombucha continue to convert the sugar into a trace amount of alcohol at this stage, and develop more carbonation.

This sealed fermentation step only lasts for a few days at room temperature, before refrigerating and serving.

Once the bottled kombucha has chilled long enough to halt fermentation, it’s ready to drink and enjoy!

The Recipe

Now that you understand these kombucha basics and the lingo surrounding the process of making it, are you ready to make your own batch?

The recipe is all yours! Go forth, and ferment!

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Cooking by the Numbers…

Step 1 – Prep

First, prepare yourself for an adventure that may last for weeks – though most of this time will be passive, are you ready for that commitment?

Yes? Good!

Now, let’s break down the tools and ingredients that you will need for the first and second fermentation.

First Fermentation Ingredients and Tools:

There are some very important ingredients and tools that you will need to start the recipe. Make sure you have them all ready before you begin.

Tools and Utensils:

• Liquid and dry measuring cups
• Whisk or mixing spoon
• Kitchen or paper towels
• Lint-free, tight-weave cloth
• Rubber bands
• 1 4-quart pot
• 1 1-gallon glass jar
• Straw or small ladle
• Disposable gloves
• Thermometer

Ingredients:

• 12 cups water
• 1 cup organic granulated sugar
• 8 bags unflavored organic black tea or 3 tablespoons loose-leaf organic black tea
• 2 cups starter tea
• 1 SCOBY

For the fermentation process, it’s best to store the kombucha in a glass jar, rather than a reactive metal material or porous plastic. The nonporous and nonreactive glass will not absorb any smells or stains from the liquid, and it will be easy to clean.

You should also choose a jar that has a wide, open mouth – this will be best for allowing proper airflow, and it will be easier to pour the liquid into and out of the opening.

Steep the tea for 25 minutes – the liquid will darken and it will be very aromatic. You are creating a tea concentrate in this step before adding the remaining liquid. And there’s no need to keep it warm so don’t place a lid on top of the pot.

After infusing, remove and dispose of the tea bags. Whisk in the remaining 6 cups of water.

At this point, you want to cool the water down to room temperature. Adding the starter tea and SCOBY to hot liquid may negatively impact the fermentation process, killing the live bacteria and yeasts.

Cool the liquid to room temperature, until it’s no warmer than 75°F. Whisk the base occasionally to promote even cooling.

Once cooled to the right temperature, add the two cups of starter tea and whisk to combine.

Step 3 – Transfer Base to Jar

Make sure your 1-gallon glass jar is clean and free of any debris. Remove the lid from the jar and store it elsewhere.

Pour the room temperature base liquid into the glass jar. Use a ladle or liquid measuring cup with a spout to help cleanly transfer the liquid from the pot to the jar.

With clean hands, or while wearing gloves, gently place the SCOBY into the liquid. The SCOBY may float or sink – this does not determine its quality.

With a paper or kitchen towel, wipe away any excess liquid droplets around the rim and outside of the glass jar.

Cover the top opening of the jar with a clean, lint-free, tight-weave cloth. You can use various types of cloth such as a tea towel, bandana, or t-shirt.

Do not use cheesecloth for the covering! The loose construction of the thread is not a safe storage option, as the openings will be large enough for flies, other insects, or other contaminants to enter.

Tightly secure the cloth around the top of the jar with one or two rubber bands. The cloth should be taut and it should cover the opening of the jar completely.

Step 4 – First Ferment

Without shaking or moving the jar excessively, carefully transfer it to a location of the house that stays between 65 and 75°F.

You want the liquid to be stored away from direct sunlight. Not only will the warmth from direct sunlight cause the temperature of the room in which you are storing your kombucha to fluctuate, sunlight can also impair fermentation, as the ultraviolet rays have antimicrobial properties.

You also want the liquid to not be stifled during this first fermentation – allow enough airflow by keeping the jar in an open location, not a tight, dusty, or enclosed cabinet or closet.

The jar should also be placed on a stable and flat surface.

Allow the jar to sit undisturbed for 1 week before testing. Take note of the timeframe so you know when to check – you can label the jar, or you can write a note in a calendar.

The contents in the jar may start to emit a subtle vinegary smell, and the original SCOBY may float or sink.

During this time, you should start to see a new SCOBY developing on top of the liquid – this is a visual sign that your liquid is healthy and properly fermenting – yay!

The SCOBY will start out as a thin, slightly see-through, gelatinous film on top, and will continue to grow, thicken, and darken in color.

You may notice some excess growth on the SCOBY, like brown strand-like pieces attached to it. This is not a concern, and is another sign of healthy growth.

However…

If the SCOBY looks like there is fuzzy mold growth on it in a blue, white, green, or black color – like the nasty kind you might find on old bread or cheese – this is a telltale sign that your base has become contaminated and is no longer safe to consume.

You will need to dispose of everything – everything! – in the jar and restart the entire process with a new SCOBY.

Don’t be discouraged! Mistakes happen in the kitchen! The second time around, make sure all of your products and equipment are clean, and that you are following the recipe and proper storage protocols closely.

Step 5 – Taste Test

After the first week of fermenting, the base is ready for the first taste test to check its status. Carefully transfer the jar to a clean work surface for testing.

Remove the rubber bands and towel from the opening, and insert a clean straw or ladle into the liquid. Pull out some of the liquid, and taste it.

How does it taste? Take note of its flavor and texture.

At this point the liquid should have a subtly acidic taste, like vinegar. It should not be overpoweringly sour. You’re looking for an approachable sour taste here, but it should still be slightly sweet.

As for the texture, there may or may not be some effervescence – that will continue to develop during the second fermentation.

If you’re happy with the taste, you’re free to move on to the second fermentation!

However, if you prefer a stronger sour taste, the base needs more time to ferment. Re-secure the opening of the jar with the towel and rubber bands and allow it to sit for 5 additional days.

Continue retesting in 5-day increments to achieve your preferred level of acidity. Depending on how strong you want the kombucha to taste, this can range anywhere from a total of 1 week to 3 weeks.

Step 6 – Prepare the Flavorings

As you are nearing the end of the first fermentation, now is the time to prepare your flavorings.

Flavorings for kombucha will vary from recipe to recipe – you will see recipes using whole pieces of fruit, fruit juice, fruit syrup, fruit puree, or an unflavored or flavored simple syrup.

I highly encourage you to research and try different methods!

All of these are acceptable to use, but they will yield different results. As you continue to experiment with each new kombucha batch, your own personal experiences and preferences will eventually guide you to what you like the most.

In my own experience, I prefer to use natural fruit-flavored syrup recipes. A concentrated, liquid syrup will more easily blend with the base, and you’re able to control the sugar content better than you might with a plain piece of fresh fruit, whose sweetness level can vary depending on the season or level of ripeness when it was harvested.

Also, the bottles are far easier to clean when you’re done if you’re using an all-liquid mixture, rather than having to fish out chunks of mushy, unappetizing fruit pieces!

I have used homemade fruit syrups with great success throughout the past few years of making my homemade kombucha.

Try any of our berry syrup recipes, and play around with any additional flavorings as you are cooking the fruit and sugar together. For example, add a few slices of fresh ginger, dried lavender, or other spices.

Just be sure to strain out any ingredients you might be using for infusing before you start filling the bottles in the next step.

When using juice, puree, or syrup, stay within the range of 1/8 to 1/4 cup per 16-ounce bottle.

I would advise against adding any more than 1/4 cup – you don’t want to add an excessive amount of additional sugar, or else the liquid may over-ferment and over-carbonate in the bottle, causing a forceful explosion of the contents inside when you release the cap for the first time.

Step 7 – Assemble in Grolsch Bottles

When you’re ready to assemble, set out 6 16-ounce Grolsch bottles with airtight swing-top caps on a clean work surface. Set out the flavorings you have chosen to use.

Set out the jar with the kombucha base, and remove the rubber bands and towel. With clean hands, wearing gloves if you choose, remove the SCOBY and set it aside for storage – more on that soon.

Whisk the liquid thoroughly.

Using a funnel, pour 1/8 to 1/4 cup of fruit puree, fruit juice, fruit syrup, or simple syrup into each bottle. The amount that you should add will depend on how sweet you want the kombucha to be.

Next, pour the kombucha into each bottle, using a funnel and ladle. There will still be about 2 cups remaining to set aside for storage – more on that soon, as well!

Leave about 3/4 inch of headspace at the top of each bottle – you want to leave some space for the carbonation to develop.

Wipe off any excess liquid from the lip of each bottle with a clean towel. Seal each bottle with the swing cap.

Please do not shake!

After filling the bottles, you will have some starter tea from your first ferment left over.

Step 8 – Store the SCOBY and Starter Tea

You now have doubled your SCOBY stash for future use – you still have the first SCOBY you used for the base, and now you have a completely new one that formed on top.

Save them both!

SCOBY has a significant shelf-life – even after multiple use, it can last for months when stored properly. And it doesn’t need much TLC!

Start a “SCOBY Hotel,” what the storage area for the SCOBY is popularly called.

The setup is similar to the jar assembly in the first fermentation – place the SCOBYs on top of one another in a glass jar, pour the 2 cups of starter tea you have on reserve over them, and secure a clean cloth and rubber band over the opening.

Store them in the same location that you store your jar during the first fermentation step.

The jar for this can be a much smaller size than a gallon – start with a quart-size jar. Depending on how many you want to save at a time, you may need to upgrade to a bigger size eventually.

As long as each SCOBY is fully submerged in the starter liquid, they can keep for months.

For general maintenance, if you haven’t made a new batch of kombucha recently, check on them every 2 to 3 months – remove each SCOBY, dispose of the older SCOBYs, clean and dry the jar, replace the used cloth with a clean cloth, and refill the jar with the SCOBYs and fresh starter tea to keep them submerged.

If you continue making kombucha on a regular basis, you will have a consistent cycle of new SCOBYs and starter tea available.

Step 9 – Second Ferment

When the bottles are all assembled and sealed, store them in the same location where you completed the first ferment at room temperature, or preferably in a closed cabinet in case of potential carbonation explosions – it’s better to be safe than sorry! This may happen if the lids are not secure enough, or if you’ve added too much sugar. Airflow isn’t important during this step.

Allow the bottles to ferment undisturbed for 1 to 3 days, but no more than that! Keep note of the length of time on the jar, or in your calendar.

If you prefer less carbonation, one day is all you need. If you prefer more carbonation, allow it to ferment for up to 3 days total.

Again, to prevent a potential explosion, don’t try to bottle-ferment for longer than 3 days. Or you may be cleaning up a big mess…

Step 10 – Chill and Serve

After the set time is complete, immediately transfer all of the bottles to the refrigerator. The cold temperature will stop the fermentation process.

Chill for at least 24 hours – kombucha is best served cold and crisp, and 24 hours of chilling is required to slow fermentation.

As an added precaution, open each bottle over your kitchen sink when you’re ready to enjoy your homemade brew – just in case the pressure that is released is strong enough to discharge some liquid.

Enjoy every refreshing sip – you’ve earned it!

Store sealed bottles in the refrigerator for up to 3 months. Open bottles will immediately start to lose their effervescence, but they are still safe to drink if stored in the fridge for up to 3 days.