SCOBY — What Is That?

Is it really necessary to kickstart the fermentation process?

5/16/20236 min read

WHAT IS SCOBY?

SCOBY stands for a Symbiotic Culture of Bacteria and Yeast. Bound together by cellulose nanofibers, they form a gelatinous shell — so called pellicle that resembles a mushroom. Hence it is often described as a kombucha tea fungus.

Technically speaking, Symbiotic Culture of Bacteria and Yeast is actually what is in the kombucha liquid, not the tea mushroom itself (although it contains some of the bacteria and yeast too).

The latter is a cellulose mat that is a byproduct of fermentation and takes the form of a membrane. Given the right conditions, the membrane forms spontaneously to separate the ecosystem of bacteria and yeast from the outside world during the fermentation process.

The membrane, which forms on top, provides a kind of protection that prevents anything from getting into the kombucha, and prevents water from evaporating from it. Hence, the newly forming mushroom acts as a "sealant" so that fewer bubbles escape and the kombucha becomes slightly more carbonated during the first fermentation.

In the kombucha industry it has become accepted to refer to the kombucha mushroom as SCOBY, so let's stay with that nomenclature. Although to make things clear, I'll throw in a small summary of these terms below:

SCOBY (Symbiotic Culture of Bacteria and Yeast) — tea mushroom / tea fungus / jellyfish / cellulose mat / pellicle,
Starter — mature kombucha containing cultures of bacteria and yeast, necessary to start fermentation.

HOW DOES SCOBY LOOK LIKE?

Healthy SCOBYs come in different shapes, sizes and colors, depending on the vessel, environment and ingredients used during fermentation.

New tea mushrooms are usually creamy white in color. The ones that have already been used to make kombucha become stained from the tea and turn brown over time. However, if you make fermented tea on hibiscus flowers, the medusa will turn a beautiful pink color.

Often with SCOBY you can see brown threads floating. These are yeasts that convert sugar into ethanol and carbon dioxide. They look super bad, but contain a lot of B vitamins and help kombucha produce more bubbles.

IS A TEA MUSHROOM NECESSARY TO MAKE YOUR OWN KOMBUCHA?

You don't need to buy the pellicle to perform your first fermentation.

What is necessary to make your own kombucha is a starter — that is, mature (at least two weeks old, preferably six weeks old) unpasteurized kombucha, made from plain tea, and containing active bacteria and yeast.

When brewing kombucha, you will notice SCOBY forming over time. It is a great indicator of whether fermentation is going well.

So if you see a thin jellyfish forming at the top, it's a sign that the bacteria and yeast are actively working to produce your delicious beverage!

WHAT IF MY SCOBY DOESN'T WANT TO GROW?

I often get the question "why my SCOBY doesn't grow?". It almost always turns out that the mushroom hasn't had a chance to form because (as corny as it sounds), it didn't get enough REST.

If you move the jar every day to see what's going on with your kombucha, the cellulose nanofibers pull away from each other, making it impossible for the pellicle to form.

So if you're really motivated to grow a tea fungus in your kombucha, it's best to set it aside for 7 days and DON'T MOVE THE JAR.

If you are motivated to grow a thicker SCOBY (it may still be very thin after 7 days of the first fermentation), pour some kombucha from the setting (200-500 ml), add a couple of tablespoons of cane (or white) sugar — the more, the more nourishment the bacteria and yeast will have. Set the jar aside (protected from the top with a breathable cloth) for a month (or even more time) in a warm and dark place.

After a long time of REST, check if the pellicle has formed. Now, you can repurpose the jar to create a SCOBY hotel.

WHAT IF MOLD HAS APPEARED ON MY SCOBY?

Before you take measures to neutralize the unwanted guest (pouring out the kombucha, throwing out the SCOBY and scalding the jar with hot water), make sure that what you see is indeed mold.

Often mold is mistaken for a strong tea deposit, yeast or for a strange appearance of a forming SCOBY. I've pasted photos below that illustrate various scenarios:

TEA FUNGUS NAMES

In America, the tea mushroom is most often called SCOBY or pellicle (meaning thin skin / membrane). Internationally, the mushroom is also referred to as kombucha sponge (Germany), tea mold (Denmark), miracle mushroom (France) and medicinal mushroom (Bulgaria).

HOW IS SCOBY DIFFERENT FROM VINEGAR MOTHER?

SCOBY contains a much lower percentage of acetic acid (0.5% to 1%) than vinegar mother (5% to 20%). In addition, SCOBY consists of acetic acid bacteria (Acetobacter) as well as yeast (mainly Saccharomyces). In vinegar there are not as much yeast as in SCOBY.

Making kombucha on vinegar mother (or on vinegar starter), you would just produce a sweet vinegar resembling kombucha's taste.

MY SCOBY SANK - DOES THAT MEAN IT DIED?

If your tea mushroom sank to the bottom of the vessel, don't worry! SCOBY is alive and ready to ferment!

HOW TO GROW SCOBY FROM COMMERCIAL KOMBUCHA?

To grow SCOBY from commercial kombucha, buy unpasteurized kombucha made with tea alone (without any fruits/flavour additives).

Then pour the drink into a half-liter jar, add 10 tablespoons of cane (or white) sugar, stir it decently, secure the jar from the top with an air-permeable cloth and set it aside in a warm and dark place for 3-4 weeks.

After this time you should grow a SCOBY about a 1-centimeter wide.

If you want to grow SCOBY with a larger diameter, you can pour the drink right away into a larger 4-liter jar. In this case, the tea mushroom will need more time to form, so it's a good idea to give it at least 6 weeks of rest.

HOW LONG DOES A SCOBY LIVE?

SCOBYs do not have an expiration date and can live virtually forever (as long as they are fed and dipped in kombucha liquid).

HOW TO FEED YOUR SCOBY?

You can feed it by regularly adding cooled sweet tea (black, green without additives).

WHY YOU SHOULDN'T STORE YOUR SCOBY IN THE REFRIGERATOR?

Low temperatures hibernate bacteria and yeast that are necessary to protect kombucha (as well as tea fungus) from various pathogens.

When SCOBY that has been stored in the refrigerator is reused to make kombucha, the first batch or two may (or may not) turn out fine, but eventually mold may appear in the brew.

IS THE TEA MUSHROOM EDIBLE?

Pellicle mainly consists of cellulose, an insoluble fiber that is beneficial to the health of our intestines.

Eating SCOBY raw can seem very daunting, so you can experiment with it in the kitchen!

My favorite way of eating tea fungus is SCOBY SNACK (aka SCOBY Fruit Leather), which I make in a very easy way by blending SCOBY with fruit and drying its thin layers in the oven.