How To Care For Your Kombucha SCOBY So It Lives For Years
How long does a SCOBY live? In theory, it can live forever. That’s because the microorganisms in the symbiotic colony of bacteria and yeasts (the SCOBY) mostly reproduce by splitting into two, making identical copies of themselves. As the SCOBY thickens and adds layers, it’s “cloning” itself, and – theoretically – with a steady supply of oxygen and nutrients this process will never end. Any of the yeasts and bacteria that die off are leaving little copies of themselves behind.
In practice, a SCOBY usually isn’t immortal. Although many people have maintained the same “mother” for several years, most people eventually end up switching to a newer “baby” (although since that baby came from the mother, it’s also a clone …) for several reasons:
- the SCOBY is contaminated because of mold, dirt, or dust
- the yeast/bacteria ratio in the SCOBY is unbalanced
- the SCOBY is “flavored” by contact with a strong tea or other ingredient
- the SCOBY weakens during experiments with herbal tea or other non-standard ingredients
However, with the proper care, you can keep your SCOBY family in good health indefinitely, by taking care of the mothers, treating the babies carefully, and following the guidelines below.
Active vs. Dormant SCOBYs
One reason that a SCOBY can live such a long time is that it can go “dormant” when the conditions for growth and reproduction aren’t exactly right. Yeast and bacteria are hardy microorganisms, and can survive long periods without any food or oxygen. In fact, recent studies using the resources at the International Space Station and an attached science lab, the European Technology Exposure Facility (EuTEF), proved that bacteria can even withstand the super-cold and radiation-bombarded environment of space. Obviously, the kitchen in your apartment is a safer place than that!
An active SCOBY is one that is taking the nutrients from the liquid it’s in and the air above that liquid, and using those nutrients and the oxygen from the air to reproduce. The byproducts of this process are what do the work of fermenting the tea and filling it with the probiotics, vitamins, and organic acids that make kombucha a healthy drink. When there are no more nutrients, the SCOBY becomes dormant.
A dormant SCOBY is “sleeping” while it waits for more nutrients and oxygen to be provided. However, even if there is plenty of food for the SCOBY, it will still go dormant if the temperature has gotten too low for the microorganisms to function. That’s why one of the ways that you can take a break from brewing without damaging your SCOBY is by putting it into the refrigerator.
If the SCOBY goes for too long without food and oxygen, or if the temperature gets too cold, the SCOBY will start to die. Since it’s a collection of microorganisms and not one single creature, how long this takes will depend on how big the SCOBY is, how healthy it was to start with, and how bad the environment is. For example, putting your SCOBY in the freezer will probably kill it completely, but leaving your SCOBY in a batch of kombucha tea and putting it in a dark cupboard for six months might just give you a SCOBY whose outer layers have died off, but whose inner colony is still relatively healthy.
Care and Feeding of the SCOBY
Whether you’re working with an active SCOBY or a dormant one, it’s important that you provide the right environment for it. That means the right pH level, the right amount of food, the right kind of food, and a place that is protected from extreme temperature, contamination, and invasive creatures like insects and mold spores.
The organic acids (acetic acid, malic acid, and gluconic acid, among others) produced by the SCOBY are part of what naturally protects the colony from harm. The low-pH environment prevents mold from forming, and also fights off bacteria like E. coli that often cause problems with other food and drink products. In order to help your SCOBY in this fight, you need to give it an acid boost.
Always add acidic starter to your tea. When you mix up a batch of sweetened tea to start brewing kombucha, you need to add some sort of acidic liquid to lower the pH. Although the SCOBY will immediately start working on the sugars in the tea to create its own acids, the natural acids will take a few days before they lower the pH enough for safety. During this initial period, the SCOBY is vulnerable, especially if it’s a “baby” SCOBY that is thinner, and has fewer microorganisms to produces the acids. If you don’t have an old batch of kombucha tea, or any liquid at the bottom of a SCOBY hotel, you will need to add an equivalent amount of distilled white vinegar. Always use the correct ratios for brewing kombucha tea to keep your SCOBY protected.
Always keep the acid level balanced when storing SCOBYs. If you’re setting up a SCOBY hotel (more on that below) you also need to provide an acid environment, even when you’re storing a batch of older, healthy mothers.
Always monitor your pH levels. The correct pH for a batch of plain, unflavored kombucha tea is between 2.5 and 4.5, but it’s a good idea to keep the pH on the lower end of the scale. While the three main bacteria that cause food poisoning (E. coli, Listeria monocytogenes, and Salmonella) generally do not survive at pH levels lower than 4.6, keeping the pH level at 3.5 or lower will help ensure that you keep your kombucha safe to drink.
NOTE: Test strips and monitors that show you the pH level of your brew are two items of useful kombucha brewing equipment that will help you be a better brewer.
The SCOBY isn’t picky – it only wants the best! To make sure you have a thriving, healthy colony, be sure to give your kombucha SCOBY what it needs.
Tea. The essential nutrients that are found in the leaves of the Camellia sinensis plant are what the SCOBY needs to survive. This includes caffeine. While there are ways to make caffeine-free kombucha you’ll need to refresh the colony with a strong batch of regular tea to keep it going. There are many different types of tea for kombucha brewing that give you a wide range of flavors. If you want to experiment with herb teas, it’s a good idea to wait until you have several backup SCOBYs to test your recipes with.
Sugar. Just as you can try out different tea blends, you can also experiment with different types of sugar when brewing kombucha. Stay away from artificial sweeteners; the chemicals may harm the SCOBY, and the SCOBY will starve because there are no true sugars for it to use for food.
Other ingredients. While it’s best to use filtered water when brewing kombucha, any type of non-chlorinated tap water will probably not harm your SCOBY in the short term. For long-term storage, be sure to use filtered water. It’s a good idea to keep your flavoring ingredients away from the SCOBY and only use them when you bottle the tea when making second ferment kombucha. The SCOBY could use the sugars in fresh fruit, for example, but the fruit will also attract mold and insects, increasing the chances for contamination.
Create a SCOBY Hotel to Store Extra SCOBYs
If you brew more than a few batches, you are going to be left with extra SCOBYs. Now you can throw these away if you wish (keeping only the baby scoby), but then you are left with a situation where if your main SCOBY dies, you are out of SCOBYs and won’t be able to brew any more Kombucha. Or it could be you want to experiment with brews that may damage or kill your SCOBY — such as Kombucha Coffee or using brown sugar or molasses instead of white or cane sugar.
Or maybe you just want to take a break from Kombucha brewing for month or two.
Whatever the case is, you need to create a scoby hotel — a place to put and store extra backup scobys. When you need an extra scoby, you can simply retrieve one from the hotel.
Setting Up a SCOBY Hotel
We’ve given a complete guide to creating (and caring for) a SCOBY Hotel — so make sure you check that article out.