ACK! Attack of the Killer Mold

So just writing about my Kombucha angst yesterday inspired me to get up and brew some fresh Kombucha. I reduced the number of jars I’m brewing from 4 to 2 and put the month old stuff into my vinegar bottle.

And then I opened up my jar with my Betsey Pryor SCOBY and look what I saw.

A very bad case of mold on top of a kombucha culture appears in large green circles and black coloring. The mold is dry and dusty, and completely foreign to the culture.

YIKES! I have NEVER had mold on any of my SCOBYs ever. So I guess I’ll just have to say goodbye to Betsey’s SCOBY for now. I threw the whole thing away. The SCOBY was covered with mold and very thin. The original mother stayed on the bottom the whole time.

Truthfully, I did not follow Betsey’s directions to the letter. I used filtered water like in all my other Kombucha and organic tea and evaporated cane juice. None of which is recommended by her.

Oh well.


If you encounter mold, it is imperative that you throw everything away. DO NOT wash off the SCOBY and try to reuse it. DO NOT save any of the liquid that had mold.  The spores persist despite rising in vinegar.  Mold, while not deadly, is not to be consumed.  It is fuzzy, blue or black, grow on top of the SCOBY and is immediately identifiable.  If you’ve seen mold on bread, then you know exactly what it looks like.

This is one of the reason why you have got to have a SCOBY HOTEL.

If you are unsure if your culture is growing mold or not, send me multiple photos from different angles and I will help you figure out what is going on.

This is still the only time I’ve ever encountered mold – it is quite rare.

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Responses to ACK! Attack of the Killer Mold

  1. Hi Hannah:
    Wow…the more info I read, the more discouraged I get by all the conflicting information. I’m especially confused by all the refrigerate/don’t refrigerate info I’m reading. I was excited to discover that a reputable health store in town was carrying scobys – but they were kept in the cooler/refrigerated section. I was disappointed when I read that you really think using refrigerated scobys is a BAD idea, especially as the scoby I first ordered and had shipped to me resulted in mold in my very first batch. If I order one from you, how long do you think it would take to get to me? I’m in Canada.

    Thanks very much,

    • Sorry to hear you are feeling discouraged. The problem with refrigeration isn’t that it could NEVER replicate but it does not create an environment in which the culture will thrive. With all ferments, you will yield the best results when you have the ideal brewing conditions.

      We ship cultures all over the world including Canada. You choose the ship method, either First Class (takes up to 2-3 weeks) or Priority (3-7 days). The SCOBY is a hardy organism and travels well the way we pack them.

  2. Could you email me? I would like to send you a picture of my kombucha. I’m not sure whether I have mold growing or if green particles from the tea mixture are just stuck to the edges of the baby SCOBY. There is a green/black ring around the top, but it doesn’t look spotty anywhere in the middle.

  3. My first attempt at brewing kombucha went moldy too. I threw out the baby and the tea, but I was wondering if I can try again with the same mother? The baby had mold on the surface and the mother was mold free, roughly the same color as when I got her and sitting in the bottom of the container. I put her in some vinegar for now. I know you said to throw it all out, but I’m reluctant as I spent ten bucks for a starter kit.. Do you think I could try another batch with the same mother?

  4. My kombucha got moldy, this is the first time i’ve tried brewing kombucha, and i want to know what i did wrong that let mold grow. i know i need to use sterile glass jars to brew it in, like, just out of the dishwasher, right? what about the cloth i cover it with?
    i have 1 more starter scoby i can try with, but if i get this one moldy too, i’m out of luck and have no more scobies to keep trying again, so i want to get it right this time. help?

    • Mold generally comes from a contaminant in the environment and usually enters the brew within the first 3 days of brewing. If you would like to discuss the specifics of your brewing process, I’m available for phone consulatations. Send me a message via the feedback form tab on the left hand side of the screen for more details.

  5. Hi Jesse,

    Mold is caused by different factors. Before the Kombucha has a chance to come to a sterile pH (usually takes about 3 days for a gallon sized vessel), the liquid is susceptible to being invaded by other types of bacteria or yeast.

    If you have mold, you HAVE TO THROW YOUR ENTIRE SCOBY and KOMBUCHA AWAY! Mold is deadly and not to be messed with.

    It can be caused by being your brew being too close to plants (the pollen can mess with the culture), or being placed in an unideal location (under the sink) or by not having a good amount of starter liquid (which is already at the proper pH).

    Drop me a line at and I’ll help you troubleshoot your situation.

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