Answered: All Your Questions About Fermentation and the SCOBY

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What is a SCOBY and what does it do?

The name SCOBY is an acronym that stands for Symbiotic Culture Of Bacteria & Yeast. It is used to brew kombucha and is looks like a large, pale, mushroom.

Physically, it is a mat made up of cellulose in which live organisms, principally bacteria and yeast live. It is these organisms that eat tea and sugar and turn the brew into raw kombucha.

When should I replace my SCOBY?

The SCOBY, along with the starter fluid is what ferments the tea and sugar that results in kombucha. It can be used over and over, if it is handled properly. Each time the kombucha brew ferments, it will produce a baby SCOBY that could be used to ferment another batch of kombucha. In practice, you want strong stater and a SCOBY that is at least 1/4 inch thick to brew your kombucha so that it finishes fermenting the brew in about a week or so.

You will need to replace the SCOBY if it develops mold or dries out. You may also want to replace it if the SCOBY and starter fluid become too weak, which can happen if you don’t leave some of the starter fluid in the brewer when you bottle.


Related: Learn all the ways to obtain a SCOBY and start brewing

Which SCOBY is the baby?

While a batch of kombucha is brewing, a thin layer of bacteria and yeast forms on the surface of the brewing container. This is often referred to as a baby SCOBY. Often the baby is attached to the “mother” SCOBY, which results in making the mother thicker.

The baby SCOBY could be used to ferment another batch of kombucha. In practice, you want strong stater and a SCOBY that is at least 1/4 inch thick to brew your kombucha so that it finishes fermenting the brew in about a week or so.

Are SCOBY and mother the same?

The SCOBY, an acronym for Symbiotic Culture Of Bacteria & Yeast, is a cellulose mat infused with the bacteria and yeast that together ferment the sugar and tea and create kombucha. The SCOBY is often referred to as a Mother.

This term is also used in bread baking when referring to the original sourdough starter, and also in the making of vinegar which starts with a different but similar looking organism.

Can a SCOBY go bad?

A SCOBY, when handled properly, should not go bad. It should be covered at all times with liquid, so it doesn’t dry out. The air around it should be protected with a cover to prevent flying insects from landing on it and laying eggs, which would be disgusting.

If the pH of the brew becomes too alkaline, the SCOBY will be less protected and could develop mold. Mold looks like a furry growth, usually green. In any of these situations, the SCOBY would probably have a bad odor. If any of these events do occur, it is necessary to throw out the SCOBY and the entire batch of kombucha, as it could become unsafe to drink.

Is a SCOBY vegan?

Yes, a SCOBY should be vegan, since it is composed of cellulose, bacteria and yeast which are not animal products. Kombucha should also be considered vegan. That said, some brands of kombucha use refined sugar in the brewing process, and some sugar is refined using animal byproducts. We always recommend using organic sugar when making kombucha at home.

Is a SCOBY a pellicle?

The short answer is yes. The term pellicle refers to the SCOBY, which is in actuality, a cellulose mat infused with bacteria and yeast. It is this combination of microorganisms that ferment the tea and sugar producing kombucha.

Technically, the starter tea contains these same microorganisms and can make kombucha without the pellicle, but when most people refer to SCOBY, they mean the pellicle and the microorganism simbionte.

Can I cut my SCOBY in half?

You can cut your SCOBY into as many pieces as you want–it will not be hurt. Use a sharp scissors or blade that is clean and dry. We usually go the additional step of dipping the cutting tool into some distilled white vinegar or kombucha starter, since anti bacterial agents could harm the SCOBY.

Pieces of the SCOBY, along with strong starter liquid can brew kombucha from a solution of sugar and tea.

Should I push my SCOBY down?

Sometimes, during the brewing process, the SCOBY will rise up in the brew and start to push up out of the brewing jar. It is better if the SCOBY does not get dry, so you should push the SCOBY gently back down into the brewing kombucha. Make sure that your hands are clean and dry to prevent contamination.

Are SCOBYs animals?

No, the SCOBY is not an animal. It is composed of a cellulose mat, inhabited by bacteria and yeast. Yeast and bacteria are neither plants nor animals. They are both unique types of single cell organisms and are classified separately from the plant and animal kingdoms.

Can humans eat SCOBY?

SCOBYs are certainly unusual looking, reminding some folks of mushrooms. You may wonder whether the organism that creates delicious kombucha can be eaten. “Can you eat a SCOBY?” you might wonder. The answer is yes. SCOBYs can be eaten in various ways and it is suggested that they are good for the body.

This article, includes some interesting SCOBY recipes, such as SCOBY Jerky, SCOBY Smoothie, SCOBY Fruit Leather and more. 

Should SCOBY be refrigerated?
One of the most common questions about Fermentation and the SCOBY is, “Should a SCOBY be refrigerated?” The answer is definitely not! You may have found different answers to this question during web research. However, the long time kombucha brewing experts and folks that brew kombucha commercially never refrigerate their SCOBYs.

Here are the reasons why. One of the biggest problem you will encounter in kombucha brewing is mold. A moldy SCOBY can be dangerous. Mold can cause many adverse health effects. People with asthma or who are allergic to mold may have severe reactions. For others, mold can cause a stuffy nose, sore throat, coughing or wheezing, burning eyes, or skin rash.

The best way to insure that your SCOBY never gets mold is to keep it actively brewing, which keeps the pH in your brew in the correct range. A SCOBY living in a low temperature environment, like a refrigerator or a very cold room, will become dormant and susceptible to mold. It will also not make good kombucha if you ever try to brew with it again!

The same reasoning answers the questions, “Can I freeze my SCOBY?” and “How long does a SCOBY last in the fridge?” Don’t do it.

In any case, it is very easy to keep your SCOBY healthy without refrigerating or freezing it. Just keep it in a jar filled with tea and sugar and let some air in. It will brew kombucha and the resultant brew will keep the SCOBY healthy, even if the liquid becomes too sour to drink. The SCOBY can live like that for 2-6 months without problems.

Related: Learn clever ways to obtain your first SCOBY and start brewing.

Related: How to keep your SCOBY safe and warm

Have a question about fermentation or SCOBYs? Leave your question below.

1 Comment

  1. Bonnie shipman

    I had to interrupt my first brew( I’ve made kombucha for years). But never had to stop because of an unplanned trip. So I bottled them up and refrigerated them until I got backk.

    Now, how do I proceed, as I like to add fruit, but not sure if I need to continue to do the first time over. Also, do you use the testing strips or go just by taste?


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