What To Do If My SCOBY Sinks
My SCOBY Sinks To The Bottom – Is It OK?
Usually the culture of the kombucha, often called a SCOBY, sits at or close to the surface of the kombucha brew. Normally extending itself to the edges of the brewing container, and from there increasing in thickness, the SCOBY is like a skin on top of the fermenting kombucha tea.
However, sometimes the SCOBY culture starts sinking down the vessel, and even lies on the bottom. This can be a little alarming, especially the first time. Most people think that their SCOBY must have a problem, or could be dying – and are uncertain whether they should drink the brew or not.
Not to worry, all is well.
Everything Is Alright
SCOBY cultures do sometimes sink, to one degree or another, and this does not indicate any problems present within the SCOBY or kombucha brew. The tea is perfectly safe to drink, and there should be no problems with the fermentation process due directly to the SCOBY sinking to the bottom.
What can happen, is that the SCOBY does not have as much oxygen available to it as if it were on the surface. This might cause a slight slow in fermentation. A slower fermentation is not a problem, and is thought to actually produce a better quality of fermented kombucha, with higher levels of nutrients and the health giving organic acids which kombucha is acclaimed for.
If you see your SCOBY sinking down, just leave it be, and do some taste checks to see how the fermentation process is going. If the brew is still a little bit sweet for your liking at the time when you would usually cease the fermentation and either bottle or start a second fermentation, then leave it for a little bit longer to let the fermentation continue and mature fully. If you have not heard of second fermentation, and want to know more, have a look at How To Make Second Ferment Kombucha (And Why You Absolutely Should).
What Are The Possible Causes Of A Sinking SCOBY
Though not detrimental to the brew, and not necessarily an indication of a problem within the SCOBY, there are a few causes for SCOBYs sinking.
One of these causes can be reduced yeast activity. Often if the SCOBY culture has been in a dormant state, such as stored in the dark with infrequent additions of nutrient rich tea, or kept in the refrigerator, the yeasts will be in a ‘sleepy’ state. This means that their activity will be a bit muted.
The yeasts are responsible for the production of carbon dioxide (that is what makes your kombucha tea fizzy). The carbon dioxide which is produced by the yeasts keeps the SCOBY culture suspended on the surface of the ferment. Some carbon dioxide is captured between the layers cellulose in the SCOBY itself. This can hold it up at the surface.
Temperature Of Ferment
This cause is actually also an linked to the yeast activity within the SCOBY. There have been reports saying that SCOBYs seem to sometimes sink when the temperature drops, and when warmed next to a heater, fridge etc, then slowly rise once more.
This is most probably linked to the yeast activity within the SCOBY, because the yeasts become more vigorous in warm temperatures, and less vigorous in when the temperature drops. If the yeasts are in muted state due to the cold, then this will affect carbon dioxide production.
What To Do
It is not necessarily vital to spring into action if you see your SCOBY culture pulling a sink on you. ‘Sinkers’, as they are fondly termed, sometimes produce some of the best ferments. Some SCOBYs will sink and rise easily, and others just might not want to float at all. This is most probably because they are more dense in consistency than the average SCOBY, meaning that there is less room in amongst the layers for carbon dioxide to lodge, resulting in the SCOBY being less buoyant.
So don’t rush off and buy an electric blanket, or do anything else drastic before you have considered what’s going on with the SCOBY overall. If you think that the temperature is a bit low for fermentation to easily take place, providing the ferment with warmer conditions might be a good option, but not necessarily to make the SCOBY rise, as that is neither here nor there. Your SCOBY sinking might just be the alert you need to warm up the brew slightly. If you are experiencing really slow ferments (above 4 weeks) then it is a good chance that the temperature is quite low for the SCOBY. There are also other causes for ferments taking abnormally long times, so if you are experiencing this, first read What To Do If My Kombucha Brewing Is Too Slow. However, if the temperature is definitely too low – less than 64o Fahrenheit (18o Celsius) then you can also go straight to Cool Weather SCOBY Care: Brewing Kombucha in Cold Weather for good advice and extra information on brewing kombucha in low temperatures
If your SCOBY has come out of a state of dormancy, such as your SCOBY hotel or out of the fridge, then it will probably take a few brews to get it up to speed. In this scenario, you can use extra starter in each new batch, to make sure that you are providing the SCOBY with the optimum environment to get going.
Starter liquid has a low ph level, which provides the acidic environment that the SCOBY needs to operate. If you want to encourage the yeasts, which could be the case if the SCOBY is sinking, then take starter from the bottom of your SCOBY hotel. This liquid will contain a higher amount of free floating yeasts.
SCOBY Health Know-How
SCOBY cultures are pretty hardy. Sinking SCOBYs are really not a problem, and the ferments they produce are safe to consume. The main thing to watch out for regarding overall SCOBY health, are imbalances between the yeasts and bacteria within the colony. If you want to find out more with regards to the SCOBY yeast/bacteria balance, check out these two articles What to Do If There is No Fizz in My Kombucha (No Fizz) and What to Do If There is Too Much Fizz in My Kombucha (Too Much Fizz).