Tea Fungus: Fermenting Kombucha

I feel like a bacterial nanny some times.  I move from room to room, tending to my little fermenting pots, trying to keep everyone happy and cozy.  The vinegar gets a shake to introduce more oxygen, or a move to a warmer spot in the house to help the acetic bacteria ferment faster.  The kefir gets a fresh splash of milk, the kimchi gets its gases let out, and the kraut pot needs regular topping up to keep its airlock sealed.
Last week Carla brought home a jellyfish to add to our collection.  Well, not so much a jellyfish, as a kombucha scoby.  Kombucha is fermented tea - like turning tea into yogurt or kefir.  But since it's tea, and not milk, the kombucha drink is light and refreshing, but still a bit tart and effervescent.  Plus, its chock full of healthy bacteria and a low pH.  I think of it as the Eastern equivalent of the old Yankee drink of raw honey and vinegar mixed with water.  A little tart, a little sweet, but all-in-all a refreshing tonic.
Although "kombucha" is the best-known name for this drink, I do prefer the Russian term for it: "tea fungus."  This seems particularly fitting after seeing the kombucha scoby.  To me, the scoby looks like a firmer, jellier version of a vinegar mother.  But reading about it, I found scoby is actually S.C.O.B.Y, for Symbiotic Colony Of Bacteria and Yeast.

It's actually quite clever: as the scoby ferments the sugars in your tea, it increases the acidity as it produces acetic acid.  To protect the more sensitive yeasts and bacteria from the rising acidity, the scoby produces a biofilm to protect itself.  The scoby produces cellulose to shield itself, while allowing it to still ferment the tea!

The great thing about kombucha is you can use almost any tea (food fermenting author Sandor Ellix Katz actually had a friend use his scoby to make kombucha Mt. Dew).  Right now Carla and I are using it to ferment red tea, so we can drink it at night without worrying about adding excess caffeine.  But like other acetic acid producing bacteria (like vinegar mothers) the scoby needs warm temperatures of 70-85 F, which are hard to come by in our house in the autumn and winter.  But our baby scoby seems to be pretty happy on top of the stove where it can soak up the radiant heat.

I still need to do more research to see if you can eat the scoby itself, so more to come!