How to Grow a SCOBY
If you are interested in science or want the thrill of making your own kombucha from start to finish, try growing your own SCOBY. It takes roughly 3 weeks, and depending on the temperature of your home, it may or may not grow. Here’s how to do it:
- Purchase a bottle of raw, unflavored kombucha from your local market.
- Brew 1 cup of either black or green tea, and add 1 to 2 tablespoons of white or unbleached sugar to the tea.
- Once the tea has cooled to room temperature, add the raw, unflavored kombucha, and pour into a half-gallon Mason jar, glass vessel, or brewing crock.
- Cover the jar with a dish cloth or coffee filter, securing the cover with twine, a rubber band, or the metal ring from a half-gallon Mason jar.
- Allow the mixture to ferment between 68-85 degrees Fahrenheit for 7 days.
- By day 7, a baby SCOBY should appear. If nothing is present after 3 weeks, discard the brew and begin again.
A baby SCOBY will look like a clear floating cloud on top of the fermented liquid. A lot of people mistake it for mold; don’t toss it! Allow it to grow until it is about 1/4-inch thick before using it to brew your first batch of kombucha. As it grows, you will notice that it will go from being transparent to almost cream in color.
If you use a wood stove to heat your house, you know the struggles to maintain a steady 68-85 degrees Fahrenheit in your house. Using LED lights wrapped around the vessel will help to keep the liquid warm. This is also how you can brew during the winter months.
Photo from Adobe Stock/Dewald
Sharing a part of your SCOBY is easy to do, and if done correctly, it will thrive in its new home. There are two ways to share your SCOBY: either remove the new growth when it is roughly 7 days old, or remove a piece from your existing SCOBY. To have more than one brewing vessel active at a time, divide an existing SCOBY. Here’s how:
- Wash your hands very well to protect the SCOBY from outside bacteria. Remember that a SCOBY is a live organism. Then sterilize your hands by washing them in white vinegar. Wearing food grade rubber gloves will work as well.
- Next, using kitchen shears sterilized in vinegar, cut the desired piece of SCOBY.
- Place the new SCOBY in a crock with starter tea. How much starter tea to use will depend on the vessel size being used. A one-gallon vessel will require one cup of starter tea.
If you are looking to share your SCOBY with friends and family:
- Follow steps 1 and 2 above.
- Place the cut SCOBY into a plastic zipper bag with 1 cup starter liquid.
- To help prevent leaking, vacuum-seal the bag or double bag it.
Photo from Adobe Stock/butenkow
Selecting the Right Tea
For fermented tea, you of course need tea, but what kind? Green, white, oolong, red, and black teas are the best to use when brewing kombucha, and all can provide enough nutrients to feed the SCOBY. These teas can even be mixed to create a unique flavor. When mixing teas, it is usually best to add a few bags of black tea to ensure enough nutrients are being provided to the SCOBY.
Herbal teas add amazing flavor to a brew but are generally low in nutrients. When using herbal teas, be sure black tea makes up 25 percent of the tea being used.
Teas that have been pan-fired (Earl Grey is the most common) should not be used. Pan-fired teas release an oily substance once they have been added to water. In addition to pan-fired teas, flavored teas should not be used. Ginger-peach tea is a good example of what not to use.
The teas listed here all contain caffeine. Black tea has the most, oolong is a close second, and green tea is third. Not into caffeine? That’s okay. Decaffeinated tea can be used as well for brewing kombucha!
Note: For those brewing kombucha with teas other than black, it is best to heavily feed your SCOBY after a month or more of brewing. This will ensure your SCOBY remains in good form and does the job it needs to do. To do this, brew a batch of kombucha using black tea instead of the typical tea you would normally use.
Photo from Adobe Stock/5ph
Feeding Your SCOBY
Brewing kombucha takes a lot of sugar, more than what some people are comfortable using. The most frequently asked question is whether a full cup of sugar is needed for a 1-gallon brew, and the answer is yes.
The sugar feeds the SCOBY, and without it, the living culture will starve and die (think of Audrey II, in the musical Little Shop of Horrors when she cries, “Feed me, Seymour!”). Though there are a variety of sugars available on the market, a SCOBY thrives on white cane sugar or unbleached sugar. Keep in mind that a large amount of the sugar is consumed by the SCOBY and will not remain in the fermented tea.
Brown, raw, or whole cane sugars can produce a yeasty brew that alters the overall flavor. Additionally, they can shorten the lifespan of the SCOBY. Honey (raw or filtered), agave, coconut, and palm sugars are hit or miss when it comes to feeding a SCOBY properly. Sugar substitutes such as stevia, xylitol, and artificial sweeteners contain no nutrients and will starve a SCOBY.
Photo from Adobe Stock/??????? ????
Bottling Your Brew
You will learn more about how to brew your first batch of kombucha in the pages to follow, but I first want to talk about bottling a brew once it’s completed fermenting.
Upon the completion of a ferment, the fermented tea will need to be transferred from the brewing vessel into bottles. Swing-top bottles work best for this, though Mason jars with plastic lids can be used in a pinch. The swing-top bottles allow for a tight seal that enables the natural fizz in the kombucha to stick around longer. For those interested in a second ferment, swing-top bottles are needed since carbonation is part of this process.
Using a funnel designed for swing-top bottles, ladle the fermented tea from the brewing vessel into the bottles, and leave a one-inch headspace. The headspace allows for the fermented tea to carbonate. Any less than one inch can cause an excessive amount of carbonation, which could cause the bottles to explode due to the buildup of gas within the bottle. An exploding bottle can be avoided by burping the bottle every few days.
If you are seeking more than a little fizz in your fermented tea, allow the swing-top bottles to sit at room temperature for 3 to 7 days. Bottles in temperatures cooler than 68°F may take 7 days to carbonate. If this is the case, I would strongly advise burping the bottles every 2 to 3 days.
Once the desired carbonation is reached, store the individual kombucha bottles in the refrigerator to slow the fermenting process.
Note: Burping a bottle is easy. You simply open the top slowly to release any pressure and then quickly shut it. Do this over a sink, as carbonation buildup is unpredictable. Ask me how I know this.
Photo from Adobe Stock/miket
Flavoring the Ferment
I would be lying if I said my children love kombucha, especially in its original form. It is a battle to get them to drink a small shot glass a day unless I have a flavored kombucha readily available. In truth, many adults also do not like traditional kombucha and prefer it flavored.
For those who like unflavored kombucha but seek more carbonation, a teaspoon of sugar or honey can be added to each 8-ounce swing-top bottle to help increase carbonation.
The method of flavoring a completed kombucha brew is known as a second ferment, or an F2, as you will often see it referred to. A second ferment not only lets you add flavor to the fermented tea, it also helps to create carbonation, which makes it easier to consume for many people who do not like a vinegar-flavored drink.
A second ferment begins as you are bottling a completed batch. Fresh, dried, or frozen fruit such as apples, peaches, and pineapple add amazing flavor to fermented tea. There are certain fruits that help to ensure carbonation is met. Pineapple and oranges are great options for this. In addition to fruit fresh, herbs such as mint or ginger can be added. Spices, dried herbs, and even extracts can create a more intense flavor.
Ingredients such as bee pollen, aloe vera, avocado, astragalus, ginger, and black pepper can be added for their immune-boosting properties. There are master brewers in the world of kombucha who can take beets, bacon, tomatoes, and even mushrooms to create something fantastic. I do enjoy a nice beet and thyme brew, but that’s about as daring as I get.
The options on how to flavor your home-brewed kombucha are endless! Make sure to use fresh ingredients that are not bruised or rotted in any way.
Note: The general rule of thumb to adding ingredients to kombucha is 10 to 30 percent fruit, 10 to 20 percent juice per bottle of fermented tea, 1/4 teaspoon extract per cup of kombucha, and herbs and spices to your liking.
Also from The Farm Girl’s Guide to Preserving the Harvest:
More on SCOBYs and kombucha:
- PODCAST: Kefir and Kombucha: Brewing with Bacteria
- The Benefits of Kombucha
- VIDEO: SCOBY Snacks: Kombucha Fruit Leather
- Kombucha for Health and Happiness
- Home Brewing Kombucha
- Browse kombucha starter kits and books in our online store
- Browse basic fermenting tools in our online store
Reprinted with permission from The Farm Girl’s Guide to Preserving the Harvest: How to Can, Freeze, Dehydrate, and Ferment Your Garden’s Goodness by Ann Accetta-Scott and published by Lyons Press, 2019.
Simple Fermented Bok Choy Recipe
Use this pickle on a veggie burger or make it using cabbage, radish, daikon, kohl rabi or other leafy Asian greens.
The Fabric of Fermentation: Kombucha Couture
Think kombucha is just for drinking? Check out how one fashion designer is using SCOBYs to craft sustainable, environmentally friendly fabric.
The 3 Steps of Distilling Alcohol
All about the 3 major steps in the alcohol distillation process.