What To Do If My SCOBY Is Too Thin
My SCOBY Is Really Thin – What’s Going On?
Half an inch (1.25 cm) is a considered a good thickness when selecting a new SCOBY from your SCOBY storage container – often called a SCOBY hotel (for more on how to make and manage a SCOBY hotel have a look at How to Create a Kombucha SCOBY Hotel).
But — having an extremely thick SCOBY is not really the most advantageous thing. If the thick SCOBY in question is quite mature, then the bottom layers will contain dead material, which can float off into your brew (not dangerous to drink, but who wants dead matter floating around in their health tonic and some people may be grossed out by this). An overly thick SCOBY can block oxygen from reaching the kombucha beneath the SCOBY, which can affect the fermentation process. In addition, SCOBYs can get so thick that there is more SCOBY culture than kombucha in your vessel, and the whole point is to produce lots of nice kombucha right?
If you SCOBY is getting out-of-hand thick, then you can either replace it with a new fresh one, if you have any stored, or peel/trim the younger top layers off. For guidelines on the best way to do this, have a look at How To Divide A SCOBY (Remove Baby from Mother) and How To Cut A SCOBY In Half.
However, if your SCOBY is not increasing in thickness, this is an indication that something is out of whack with the culture. This could be caused by a variety of things, such as a contaminant, low temperatures, tea type etc. Read through the list below, and analyse what conditions could possibly be affecting your SCOBY culture.
Keep in mind that if you have a new SCOBY, the SCOBY has been in stasis (say it’s been in the fridge for a while) or you are trying to reactivate a dehydrated SCOBY or you are trying to grow a brand new SCOBY from store bought kombucha, your SCOBY may be thin for a few brewing cycles — this is natural and nothing to be concerned about UNLESS the SCOBY remains very thin over multiple brew cycles.
The good news is that if your SCOBY is persistently thin, you can, by adjusting the factors which you think might be causing the inhibited SCOBY growth, you should be able to get the SCOBY back into balance and it will start growing again. SCOBYs are tough cultures, they just need the right environment to really thrive.
Possible Influences Which Can Cause Thin SCOBYs
There are quite a few potential factors which could cause a SCOBY to not grow and remain very thin. You should probably be able to pinpoint if any of the obvious ones are affecting your SCOBY (eg. tea type). I will list the factors in order of likelihood.
1. Temperature is too hot or too cold
Low temperatures are a common cause of retarded SCOBY growth. SCOBY cultures do best in temperatures between 95o Fahrenheit (35o Celsius) and 49o Fahrenheit (18o Celsius). Any hotter and fermentation will not be that viable as the bacteria will die. Any cooler, and fermentation and SCOBY growth will slow dramatically. Cold temperatures causes the yeasts and bacteria to “go to sleep”, meaning that they are in a state of dormancy. This is why some people store SCOBYs in the fridge.
If your fermentation is taking place in conditions below 49o Fahrenheit (18o Celsius), then this is probably the cause of your thin SCOBY. There a many ways of creating a warmer temperature for your brew, and sometimes merely placing it in close proximity to something in your house that is continuously running, such as the back of the fridge, a desk top which is always on, on top of a heated fish tank etc, will do the trick.
For ideas on how warm your brew, you can also read Cool Weather SCOBY Care: Brewing Kombucha in Cold Weather.
Just be aware that slow fermentation in cooler temperatures are preferable to very fast ones, which happen in warm to hot environments. Slower fermentation produce a better quality of kombucha, which is said to contain higher amounts of the health giving organic acids and enzymes. So just be careful not to go in the opposite direction by overheating your ferment. This can bring along its own set of problems, such as over activity of the yeasts.
2. Wrong Tea Type
Brewing with the wrong types of tea for your sweat tea base can cause a slow in SCOBY growth. The yeasts and bacteria feed on nutrients present within the leaves of Camellia sinensis, which is the tea plant from which black tea, white tea, green tea and oolong tea are obtained. These four teas are the best for brewing kombucha. Alternative herbal teas can also contain natural oils, which may damage the SCOBY. Flavored teas are definitely not advisable to use for kombucha making, as the chemicals present are not good for the SCOBY. For more info on tea types, check out What is the Best Tea For Brewing Kombucha.
3. Flavors Added During First Ferment
Adding flavoring to your kombucha tea while the SCOBY is still present, it is not recommended, and is often the reason for SCOBY problems, such as retarded growth. For a detailed guide on safely flavoring kombucha tea, not to mention some tempting recipes, check out How To Flavor Your Kombucha To Awesomeness and Top 15 Best Kombucha Flavors: Recipes Guaranteed To Blow Your Tastebuds.
4. You’ve Used Antibacterial Soap to Wash
Do not use antibacterial soap! Using antibacterial soap to wash the kombucha vessel, your hands, or anything that will come into contact with your brew or culture is not all at advisable. People tend to want to wash their jars and hands with antibacterial soap for hygiene purposes, but the effect that this has is that any residue from the soap will kill bacteria within the SCOBY, which will compromise its health and growth.
5. The SCOBY In A State of Dormancy
Cultures which are in a dormant state will take awhile to get going and growing. If a culture is newly purchased, has been stored in the fridge, or rehydrated, then one will probably have to be patient for a few brews, until the SCOBY has ‘woken up’ fully, to experience normal brewing times, good carbonation, and fast SCOBY growth.
The Yeast/Bacteria Balance Within Your SCOBY
The SCOBY is made up of two societies of organisms. The yeasts and the bacteria. They support each other, and live happily together within the SCOBY. However, they have to remain in balance, because if one dominates then the health of the other is compromised. This affects the overall SCOBY health, which can lead to a SCOBY which is not growing, producing more babies or getting any thicker.
An overabundance of yeasts within the SCOBY can cause a slow of growth and leave you watching your thin SCOBY wondering what’s going on. There will most probably be other signs, such as fast ferments which go tart quickly with high levels of carbonation. You should then also be able to see a lot of brown material hanging off of the bottom of the SCOBY, and or suspended at the bottom of the ferment.
To quickly and easily help the bacteria get going – you can do the following:
- Ensure that you take starter liquid from the top of the vessel in which it is sitting, as this contains fewer of the free floating yeasts.
- Try and make sure that the fermentation is not getting too warm. Bacteria will start to die off above
temperatures of 95o Fahrenheit (35o Celsius).
- Replace a portion of your sugar for the sweat tea base with glucose. Corn syrup is ideal.
If you want more information on the causes of a case of underactive bacteria and what to do to remedy it, have a look at What to Do If There is Too Much Fizz in My Kombucha.
Less likely to occur, but also entirely possible, is dominance of the bacteria population. In this situation besides slowed SCOBY growth, you will probably also encounter slow ferments with very little carbonation. A situation of suppressed yeasts and active bacteria is most common within during the first few ferments when starting with a purchased culture, or one which has been taken out of storage.
To quickly and easily help the yeasts get going – you can do the following:
- Ensure that you take starter liquid from the bottom of the vessel in which it is sitting, as this will contain a higher concentration of free floating yeasts.
- Keep the brew in a warm place. The yeasts are happier in slightly warmer temperatures than the bacteria, so this will encourage their activity. However, as yeast dominance is more likely to occur over time, be careful not to make the temperature change too extreme, and swing the balance too far in the other direction. One other caution – do not place the brew in direct sunlight as this can damage the culture as well.
If you want more information on the causes of a case of underactive yeasts and what to do to remedy it, have a look at What to Do If There is No Carbonation (Fizz) in My Kombucha.
There are other things which can damage to or inhibit a SCOBY, such as chemicals within the air (such as insect repellent or air fresheners), contact with metal, exposure to cigarette or tobacco smoke, too much direct sunlight etc, mold contaminating your SCOBY, old (dying) SCOBY, or an insect infestation.
Think about what might be present in the air or environment around your ferment, you might realize that there is something which the culture is exposed to on a continual basis which is adversely affecting it.
For more reading material on SCOBY care, you can go to How To Care For Your Kombucha SCOBY So It Lives For Years.