Sorsa Kombucha Blog

Is my Kombucha Mouldy?

Is my Kombucha Mouldy?

SCOBYs, Mould, and how to tell if my booch is healthy

Kombucha is one of the easiest ferments to master. Believe me when I tell you, anyone with any confidence level, can easily master kombucha brewing within a few tries. 

SCOBYs are hardy, difficult to kill and incredibly determined to grow. There are a few basic rules to live by when making kombucha but even if you make a few mistakes while brewing, your SCOBY is likely to pick up the slack and keep on keepin' on.

With that being said, SCOBYs are funky to look at and can be very deceiving to first-time brewers. SCOBYs will quite easily trick you into thinking your batch is mouldy and question yourself...but don't fret!  This is likely just the yeast & bacteria mingling - creating the classic SCOBY disguise.

What to expect from your brew

Fermenting is a process that continuously changes and evolves. When you start a new batch of kombucha, the SCOBY will begin to form a new layer of SCOBY across the top of your batch. This new growth, we call a 'baby SCOBY' usually starts out mostly transparent with whiter and darker areas dispersed throughout.

The lighter and darker areas are caused by yeast that has connected and collected within the layers of the SCOBY. It can turn the surface lumpy and look blue, black, green and cause a bubbly surface - but it’s all very normal. SCOBYs can be strange and are a bit weird to look at, but that's just the way they are.

The blobby bits, bumps and bubbles are all signs that your brew is happily fermenting along! :) 

The following photos all show HEALTHY kombucha batches. 

checking for mould - Healthy Kombucha batchDark yeast spots inside a new SCOBY layerNew SCOBY growth with white bumpsNew SCOBY looks weird but is healthyyeast attached to a SCOBY inside a kombucha jar

What causes kombucha to actually mould (what you don't want) 

When/if kombucha gets mouldy it will appear on the top surface of your SCOBY and it will look just like the fuzzy mould you see on bread and cheese. THIS IS VERY VERY UNLIKELY!!
In the rare case, fuzzy mould does appear. Discard the whole batch. It's not worth trying to salvage any of it. Toss the brew out and start over with a saved SCOBYs from your SCOBY hotel, or order a new one if you don't have any extra backups. 
There are essentially three main cases that cause a kombucha brew to mould:

Using the wrong type of sugar. 

  1. Kombucha cultures have evolved feeding on granulated cane sugar. So, it is important that you feed your cultures using plain white sugar. You will stress your SCOBY culture if you try to introduce an alternative sweetener such as: brown, turbidity, Demerara, stevia, honey etc.. Using an alternative sweetener will be too difficult for your SCOBY to breakdown and process and will ultimately result in mouldy brews.

Using the wrong type of tea. 

  1. Kombucha should be brewed with a base of green, black or oolong tea.
  2. If you use herbal tea or a tea with flavourings &/or essential oils, it can harm your SCOBY. 

Using a refrigerated or dehydrated SCOBY

  1. If you don't have a good quality SCOBY to start with, your brew is likely to fail. 
  2. When you use a refrigerated or dehydrated SCOBY the bacteria can be sluggish or dead and when you put it into the sweet tea, it may not be strong enough to take a foothold in your brew. It may be lethargic, allowing external bacteria resulting in mould.

The following photos show what mould on kombucha looks like.

Fuzzy mould growing on kombuchagreen, fuzzy mould growing on Kombucha Scoby 

If you're still unsure, send us an email and include photos of your brew. We can help ease your worries!

May 24, 2020

I have received my orders of 2 x gallon jars and 2 x scobys, they arrived quickly and I got started few days later. I am grateful for the complimentary saschets of tea to try
(Giving me the options) as I am new to measures and mixes.
The note attached was a very pleasant surprise and touch as if it was a friend speaking to me.
I will be reading through sorsas guidelines and tips.
Thank you very much
Kind regards

William henry
May 10, 2020

Честито Софи много се радвам за вас. Кога е датата на щастливото събитие.

Daniela Petrova

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