How To Divide A SCOBY (Remove Baby from Mother)
As long as it has the right environment, a kombucha SCOBY (Symbiotic Colony Of Bacteria and Yeast) will continue growing. This living cluster of microorganisms will keep getting larger, first by expanding to cover the surface area of the liquid it’s in, and then by continuing to increase in thickness by adding new layers to the top of the colony. These new layers are the SCOBY “babies” and you’ll get one new “baby” each time you brew a batch of kombucha with a SCOBY “mother.” If you don’t remove the baby layer from the top of the container, it will eventually merge with the mother underneath it and become part of the larger SCOBY.
Why to Divide a SCOBY
If the SCOBY just keeps getting thicker, doesn’t that just mean that you’re getting a better, healthier SCOBY as time goes by? Well, yes and no. Here are several reasons why it’s a good idea to divide your SCOBY regularly:
The Mother is Aging
Although the SCOBY microorganisms are reproducing, they’re also aging and dying off. Over time, the average age of the colony goes up. Just as with human beings, older SCOBYs can remain in good health, as long as they’ve got a healthy environment, and if you’re storing your SCOBYs in a well-run SCOBY hotel and they’re getting regular doses of fresh sweetened tea to the kombucha concentrate they’re floating in, then your SCOBYs will keep happily growing for months, and even years.
Eventually, however, your SCOBY will probably get too old to effectively ferment the sweetened tea, and you’ll need to throw it away and start using a younger SCOBY.
The Kombucha Flavor is Changing
Changing not in a good way, that is.
This could be due to the overall health and age of the SCOBY, or because it has picked up a new variety of microorganism, or because there is no longer a balance between the number of yeasts and the number of bacteria in the colony. Separating the older segments of the colony and discarding them will usually solve problems due to age and yeast/bacteria balance.
However, if your SCOBY has picked up some non-beneficial bacteria somewhere, even the newer parts of the colony may be infected. If you think that your SCOBY does not look healthy then it may be safest to discard the entire colony.
The SCOBY-to-Liquid Ratio is Skewed
Because the SCOBY keeps growing, it will eventually fill up whatever container you’ve got it in. However, since the SCOBY needs to have a constant source of nutrition (the fresh sweet tea) and stay in a protective acid environment (the low-pH kombucha concentrate), if the SCOBY gets too large then there won’t be room for enough liquid to keep it moist and healthy. In this case, you run the risk that the microorganisms will start to die off, and find that the SCOBY has gotten moldy.
When to Divide a SCOBY
In general, you should divide your SCOBY when:
- You run into any of the three situations described above.
- The SCOBY has been used for more than 4 batches of kombucha.
- The SCOBY is more than an inch thick.
- You want to experiment with new tea blends or other ingredients.
- A friend asks you for a SCOBY so they can make home-brewed kombucha.
A newborn SCOBY baby is often quite thin, so it’s a good idea to wait until you’ve gone through three or four brewing cycles to add more layers before dividing the SCOBY. Each layer forms on the top of the mother SCOBY, so the youngest (and healthiest, if all is going well) colonies will almost always be above the older layers.
NOTE: Sometimes the mother SCOBY will “roll over” in the container, putting the newer layers on the bottom, and then float back up to the surface. To avoid mixing up the new layers and the old layers, you can place a small weight on the mother SCOBY, like a clean glass saucer, to hold it below the surface of the liquid and to keep it from rolling over.
How to Divide a SCOBY
The easiest way to divide a SCOBY is to separate the horizontal layers (peel the baby, which is on the top, from the mother, which is on the bottom) Most of the time these layers will peel apart without a problem, especially if you’re dividing the SCOBY regularly (before the layers grow together completely). You’ll probably have a good-sized “baby” after the 4th batch of kombucha, when the four “babies” form a layer that’s about 1/4 inch thick.
Note, there is an alternative method of diving a SCOBY buy just directly cutting it in half (both the mother and baby in one cut vertically), rather then peeling the baby from the mother in a horizontal fashion. However, for this article we are talking about the standard removing the baby from the mother, not cutting the whole SCOBY in half.
Wash your hands and rinse them well before handling the SCOBY. Avoid using anti-bacterial soap or sanitizer. It’s a good idea to rinse your hands in distilled white vinegar before touching the SCOBY.
If your SCOBY is fairly old, the bottom (oldest) layers may be losing their resilience. A SCOBY will turn darker as it ages. You should regularly discard the oldest layers of your SCOBY, or at least not use them for brewing kombucha. There are several ways to use an old SCOBY in your kitchen, in your bathroom, and even in your garden.
As long as the mother SCOBY is healthy, you can use it for your next batch of kombucha, and store the baby in your SCOBY hotel. You can also temporarily “retire” the mother to the SCOBY hotel, and use the newer baby SCOBY for your new batch of brew. If you need to take a break from brewing then you’ll want to store both the mother and the baby. Since they’ll start growing together while they’re in storage, you can wait to separate the layers until you’re ready to begin brewing again, though you may have to cut the SCOBY in half instead of peeling it apart.
Cutting a SCOBY in half is a perfectly (and alternative method) of dividing your SCOBY.
Remember, SCOBYs are a mix of yeast and bacteria and not a mushroom. This means they can really be any shape — cutting it in pieces won’t damage it, other than change the shape and (if you remove some of the cut off pieces) reduce the surface area that comes in contact with the air. Do remember than you can grow a new SCOBY even without any SCOBY in the kombucha brew from store bought — during this process you will see tiny pieces of yeast and bacteria floating around in the brew, rising to the top to form a SCOBY. There is no form or shape of SCOBY yet there is still ‘SCOBYs’ in the mix, just really small undefined peices of it at this time.
The advantage of cutting your SCOBY in half (vertically) like the way you cut a piece of toast in half is that you don’t have to wait for the full baby to form which can take a few weeks to a month. The disadvantage is that your main SCOBY ends up in half (with smaller surface area). You basically end up with two small SCOBY’s which won’t be as horizontally big, which means they won’t have as much contact with the air.
It can take a few brewing cycles for your SCOBY and the piece you cut off to return to it’s origional shape — often only the actually new baby that forms on the surface will look like the proper ’round’ SCBOBY while the cut off piece will hang below.
Don’t worry if the layers don’t separate evenly. Because the newer layers are thin and can be fragile, sometimes the layers will end up with small rips or holes in them. When you put the separated SCOBY into the SCOBY hotel or use it to start another batch of kombucha, the microorganisms will use the nutrients in the sweetened tea and concentrated kombucha starter to quickly reproduce, and the rips and holes will disappear.