Why You Should Never Store Your SCOBY Cultures in the Fridge
This post is all about the correct storage of kombucha SCOBY cultures, and why they should never be stored in a refrigerator.
This is quite a controversial topic as far as kombucha facts go, so we are going to go into exactly what can happen when a culture is refrigerated, and briefly outline the best and easiest alternative SCOBY storage option.
While kombucha brewing is easy to keep going once one is in the rhythm, there will usually come a time – eg going on holiday – when one will need to halt brewing and store your culture until you can get fermenting again. Then there are also all of the additional baby SCOBYs which will start to accumulate! If you wish to keep some of them, and our advice is that you definitely should, they will also need a nice SCOBY-friendly storage spot.
What Not to DO
There is a widespread and popular set of guidelines for kombucha SCOBY storage which will tell you that if you wish to store your SCOBY or SCOBYs, then you should place them in the fridge in some sweet tea. The logic behind this is usually ‘that the culture will go to sleep’ and in some cases even ‘so that it will not rot’.
You should not do this. Very low temperatures such as those in the fridge do put kombucha cultures to sleep — so much so, that when taken out of the fridge they are not able to carry out good fermentation or if they do, you have a high chance of mold forming.
For long term storage in the fridge, mold may grow in your Kombucha after a few weeks even (yes, this happened to me!).
Here are couple of the things which can happen when SCOBYs come out of the fridge.
1. Flat Ferments
Once a culture comes out of the fridge, it is at half strength. Fermenting power will be weak, and your first brews with probably be flat and only semi fermented. Getting the culture back to its usual vitality could take up to 6 brewing cycles, depending on the climate in which you live, that is a long time!
2. Mold May Form in Brews
The #1 cause of moldy SCOBYs is refrigeration. Don’t do it!
Probably every brewer’s nightmare, an attack by mold is another common repercussion which happens to SCOBYs which have been stored in the fridge. The reason for this is that the low temperatures cause the whole culture’s population to slow down and become inactive.
The science of the process of fermentation is that of harnessing bacteria and yeast species to work on a stored food or drink substance. The result is that instead of the substance decomposing and ‘going off’ it is turned into a living food, which is protected by the microbes which are working on it.
This way the substance does not decompose, but is rather turned into a product which mold and other bacteria find very hard to take hold in. Naturally the culture itself is also protected from these organisms when in a strong and healthy state.
However, if a culture becomes very dormant, these protective microbes are not active enough to do anything, and the culture is just a sleepy bit of cellulose, until it has been exposed to warm temps for long enough for all of them to get going again. During this time, there is a very high likely hood that the SCOBY culture and new ferment will be invaded by mold or foreign bacteria.
Can You Store Your Fermenting Kombucha in the Fridge for a Short Time?
In short, yes, likely. But for long term storage, no.
You won’t damage your fermenting Kombucha brew in the fridge for a few days. But long term storage will cause problems. You can place your SCOBYs in a plastic bag with some starter liquid for temporary storage of a few days if you wish. I’ve done this for three weeks even and had no issues.
If you place a jar of already fermented Kombucha with some SCOBYs in it, you may be able to store such for a week or two, but you may have issues with fermentation and / or mold once you try brewing again.
However, do NOT try brewing a new batch of Kombucha in the fridge. If you try to brew a new batch of Kombucha by placing it in the fridge, you drastically increase the chance of mold forming because the tea won’t properly ferment in the fridge temperature.
Keep in mind that you can store your SCOBY in a regular container outside of the fridge for a few days or weeks without issue (the tea will ferment, but you won’t have culture damage or mold issues).
Do not brew a new batch of Kombucha in the fridge, nor place a new SCOBY hotel inside — mold may form.
How to Easily Store SCOBYs – Out of the Fridge!
Considering how easy and effortless it is to store kombucha SCOBYs outside of the refrigerator, it is a bit bizarre that anyone would have thought of refrigeration in the first place! Let’s walk through the basics.
When storing SCOBY cultures, one does want them to go into a slight state of dormancy. While the extreme level of dormancy brought on by refrigeration is obviously NOT desirable, if the cultures naturally slow down a little, this can be to your advantage. In storage, cultures will continue to grow and feed on whatever sugar there is available for them. If they are in a slowed down state, this means that they need less feeding, and grow a bit slower. Cultures growing while in storage is not really a problem, but it can get out of hand, particularly in warm climates.
However, you do not need to resort drastically low temps to achieve this. Instead of using the fridge, the best way to make your stored cultures a bit sleepy is to place them in a dark place. So, before anything else, you will need to find a nice dark cupboard, which is free from excessive dust and dirt.
We can now finally introduce, the SCOBY Hotel! SCOBY accommodation at its best, unparalleled by cold storage or dehydration. Super simple to setup and maintain, here is what you do – it is basically very much the same as setting up a new ferment of kombucha:
- Select a nice big glass jar.
- Set aside some mature kombucha from what you have made already. This mature kombucha is a very important ingredient as it will turn the storage liquid acidic in order to keep out mold and foreign bacteria.
- Filled this jar approximately 3/4 full of ordinary sweet tea and mature kombucha, exactly the same as what you do for the kombucha itself. The ratio between the sweet tea and mature kombucha, or starter liquid, should be about 2:1.
- Insert the SCOBY(s) which you want to store.
- Secure a cloth covering over the opening, taking care to not leave any small gaps where fruits flies could crawl in.
- Store in a dark and cool cupboard. The best temperature is between 70-80 o Fahrenheit (21-27 o Celsius).
That is roughly it. After a couple of weeks you can screw on a lid as the cultures will no longer need the oxygen supply. If you about to go ahead and set up a SCOBY Hotel, I would advise you to read our in depth guide on SCOBY Hotel setting up and maintenance, How to Make and Maintain the Perfect SCOBY Hotel.
Storing SCOBYs in this way is hassle free, doesn’t take up space in your fridge, and won’t damage your cultures in any way. Depending on the temperature and how often you feed them, the stored SCOBYs will be in a state of dormancy, but not so extreme that they are unable to protect themselves and their ferments from pathogens when brought out to brew with once more. After the first or second ferment, your SCOBY should be fully revived.