Friday, June 10, 2005

kombucha after mold

After the kombucha mold issue, I did some research to see what I could do about that.

It turns out that trying to keep things really clean (or even sterile!) isn't going to help much. There's a lot of mold spores everywhere, all the time. Not much chance of keeping it away.

However, you can do a lot to make things unfriendly for molds. They don't grow on really acidic stuff. So the trick with kombucha is to drop the pH as quickly as possible.

Remember that when you make kombucha, it goes like this:
1. Brew strong, sweet tea
2. Cool to body temperature
3. Add a peice of a kombucha "mushroom" and 10-20% fresh kombucha from a previous batch.

The "mushroom" (pancake, sponge, SCOBY, whatever) has the most cultures in it. The previous kombucha is primarily to lower the pH.

I like my kombucha a little sweet. After 5 days, I find it very yummy. I am trying to limit my sugar intake, so I'm more sensitive to sugar than most people (who drink a lot of cola). That also means I want to let it go a little longer, so the culture removes more sugar. I aim for about 7 days.

(I really should taste it every day until it reaches the tartness I like.)

Anyway, one of the tricks for preventing mold is to use a very acidic starter. Let a batch brew for 15 days and it will be very acidic. Hard for most people to drink, but a good substitue for vinegar on a salad.

So I started up 2 batches:
  • A large batch (3qts of kombucha in a 4qt bowl). Used distilled vinegar to help lower the pH. After 7 days, drank it & started a new batch.
  • A small batch (1qt in a 2qt bowl). Let it go a long time to lower the pH. Will use this for starters only, not for drinking.
Last night I harvested the 2nd batch from the large bowl, and was getting ready to use the small bowl to start a new large batch. All was going according to my sinister plan, until the hot water cracked the bowl. It was ruined.

Hopefully I'll find a replacement at the thrifts store. Even better, I'll find 2-3 good bowls, and be able to make enough kombucha to share with friends.


todd said...

Myself I like it strong :). I'll let it brew for at least 10 days, longer if I can stand it.

I use jars for sun tea; sometimes you can find them at the grocery pretty cheap.

Jay Bazuzi said...

I've read repeatedly about Kombucha pulling toxins out of the container it's brewed in. I only use glass. I worry that the sun tea jars, with their plastic or metal spigot, will react with the Kombucha.

Happy Herbalist said...

Mold is a fungus, and the SCOBY (Symbiotic Colony Of Bacteria and Yeast) contains fungus; yeast is a type of fungus, but the microorganisms in the SCOBY are single-celled creatures living and working together (that’s what “symbiotic” means), while a mold is one single organism made up of connected filaments, or branches. When you see a spot of mold, that’s a cluster of filaments from many different mold organisms. When you’re first starting a batch of kombucha tea, it’s important to make sure the starting pH is acid enough to fight mold. The sugar and other sweeteners that you’re putting into the brewed tea that the SCOBY “eats” are also food for mold spores, and until the SCOBY transforms enough of the sugars into acids, there is a risk that your kombucha tea could develop mold. Always use the right ratio of ingredients for brewing kombucha to avoid this problem.

Source: Is it Mold

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