Thin SCOBY – Why is My Kombucha SCOBY Thin?

Today we are going to explore some potential causes of a thin SCOBY.  Before you panic, you should know that kombucha SCOBY thickness is NOT necessarily a direct indication or reflection of the health of your SCOBY.  There are many factors that contribute to the thickness, shape, and size of your SCOBY.  However, a larger/thicker SCOBY generally does mean a faster, more efficient fermentation.

If you are consistently ending up with thin SCOBYs or simply want thicker SCOBYs to make it easier to start multiple batches of kombucha or share your SCOBY with others, there are steps you can take to thicken your kombucha SCOBYs!  Many of these steps are best practices for home-brewing kombucha in general, so get ready to learn and improve your practice!

What might harm my SCOBY or inhibit growth?

There are a number of things you should look out for (and protect your SCOBY from) in order to get the best results from your kombucha brews.  Let’s take a look at some of the risk factors leading to thin SCOBYs:

Light: Natural OR Artificial

Keeping your brewing vessel in the dark is NOT for fun— both natural and artificial light can significantly inhibit SCOBY growth and fermentation!  If your SCOBY is out in the open, move it to a dark closet with the door cracked open.  You will probably be amazed at the difference in your kombucha’s fermentation and SCOBY growth.

Movement – Patience is Key

We understand how difficult it can be to truly leave your kombucha alone for fermentation, but it makes a difference!  Every time you move your kombucha jar, forming baby SCOBY particles may sink to the bottom of your jar and the new SCOBY’s growth can be inhibited.

If you are very eager to check on your SCOBY, try to check without moving your jar. Briefly shine a light on the jar and take a peek.  At a minimum, you should leave your jar undisturbed for the first 7 days.  If you are not yet happy with the SCOBY thickness at this point, we recommend gently returning the jar to its fermentation space and leaving it for another 3 days before checking again. 

Temperature of Sweet Tea

When you start each new batch of kombucha, you will want to make sure that your sweet tea is cooled to 86 degrees F or below prior to adding your SCOBY(s) and starter tea.  If your brewed sweet tea is warmer than this when you add SCOBYs and starter tea, you risk damaging or even killing SCOBY matter in your brew.

Soap

When sanitizing your brewing vessels and equipment, you will want to make sure you always thoroughly rinse out all soap with hot water.  Soap can harm your SCOBY.

Use dish soap and avoid antibacterial soap.  If handling your SCOBYs with your hands, you will want to make sure you thoroughly rinse soap off of your hands after washing them as well.  For extra peace of mind, you can rinse equipment and your hands with distilled white vinegar after washing. 

What does my SCOBY need to grow thicker?

If you are ending up with a thin SCOBY and don’t believe any of the above risk factors apply, odds are there are some pretty quick wins waiting for your kombucha brewing practice!  Here are some slight changes and process improvements that are likely to boost your SCOBY size and thickness:

Time

If you are avoiding all risk factors, time is the most important variable involved in your SCOBY growth.  We KNOW how tempting it is to check on your kombucha every day, but leaving your SCOBY undisturbed can make a BIG difference!

If you are concerned that leaving your kombucha/SCOBY to ferment for longer will make it too tart for your taste, start small.  Try leaving your brew undisturbed for 10 days.  A few extra days can make a BIG difference in the size of your SCOBY! A normal fermentation time actually spans 7-21 days.   

If your brew is too tart for your liking after 10 days, try 9 days next time around.  If your SCOBY isn’t as thick as you were hoping, try 12 days next brew.  You can play around with the brewing time to optimize your SCOBY growth and maintain the flavor you want from your brew.  You may even end up discovering that you like a tart brew more than you had expected!

Temperature

If the ambient temperature around your brew is less than 70 degrees F, odds are the SCOBY will end up on the thin side.  This is not a problem if you don’t mind it—some people actually swear by a preference to the taste of a slower brew.  However, it will be difficult to grow a thick SCOBY below 70 degrees F.

How can you solve this?  Well, you can place your SCOBY in a warmer part of your home if possible.  Up to 86 degrees F is great for kombucha brewing.  If you like your home on the cool side, you can look into purchasing a heat mat for your kombucha.  Some mats can be set to an exact temperature and wrapped around your jar for even distribution of heat.  A heat mat is generally not necessary above 65 degrees, but it may help you to grow thicker SCOBYs if the temperature of your brew is otherwise below 70 degrees F. 

SCOBY Fuel

Another way to optimize SCOBY growth is to make sure you are setting your brews up with the ideal ratio of starter tea to fresh sweet tea.  Check out our kombucha recipe if you aren’t sure about this.  Try using a full 2 cups of strong starter tea in your next gallon batch.  Do not cut back the amounts of sugar and tea called for.  You want to make sure that you provide adequate fuel for your SCOBY, while also ensuring that you have plenty of yeast and bacteria (SCOBY matter) to consume and convert that fuel. 

Brew Some Thick SCOBYs!

We know this is a lot of information, and it can be overwhelming if you are a new brewer.  However, you will learn all of these things and more firsthand over time!  Just be patient and keep on brewing! All that’s left now is to put this new information to good use and brew some tasty kombucha with thicker SCOBYs : )