Friday, February 2, 2007

Kombucha 101

I realize that many people have never heard of kombucha, I certainly hadn't until I spent a couple of weeks in Denver (where the local Whole Foods carried 5 brands of it) awhile back. It originated in China and can best be described as a slightly sweetened tea that is soured by a jelly fish like cluster of microbes.

Kombucha appeals to me because it is much faster and easier to make than funky beers, in addition it has almost no sugar and less than .5% abv, so I can feel good drinking it whenever I want. I grew my culture (left) from a bottle of what I felt to be the best kombucha I had in Denver (Tea Chi), but there are commercially available cultures that require less work if you are so inclined or if you can't get a bottle locally.

The finished product can vary greatly depending on your culture. Some are clean and sharply acidic, but it should come as no surprise that my favorite brand had plenty of funk (in particular our old friend Brettanomyces). The tea doesn't have too much impact on the finished drink, it serves primarily as a nutrient source for the culture (and as such it can't be left out in favor of other flavorings).

Here is my basic recipe:

  1. Bring 1 qrt of water to a boil

  2. Take it off the heat and soak 2 tea bags or 2 tsp of the tea of your choice for 15 minutes (the longer brew time extracts more nitrogen and nutrients),

  3. Dissolve 2.5 oz of white sugar into the tea

  4. Cool to 70 degrees

  5. Pitch your culture and about 10% of the previous batch to lower the acidity.

  6. The culture needs oxygen, so just put a paper towel over your container and hold it in place with a rubber band.

  7. After two weeks of fermenting in the high 60's the kombucha is ready to bottle

  8. I generally put it into old plastic soda bottles with a 1/2 tsp of sugar, screw the cap on and wait for the bottle to feel pressurized (normally about 4 days)

  9. At that point I put the bottles into the fridge and they are ready to go

Sanitation is not as important as it is with beer fermentation because with kombucha not only do you already have multiple microbes working together in the culture but also it is open to the air so some microbes are going to get in there regardless of your sanitation.

The next step in my process is to build up a big enough mother culture so that I can start splitting off daughter cultures to begin playing with. In particular I hope to find out if the culture is able to do its thing in the presence of hops...

5 comments:

Rick said...

I may have just overlooked this, but where did you get the culture?

Heard of this on Basic Brewing - fyi - sounds like a good thing as my wife goes nuts for the stuff.

Kristy said...

I was glad to learn of your brewing technique! I've recently gotten into brewing myself and was wondering if you know anything about the legalities of selling your own kombucha brew.

The Mad Fermentationist (Mike) said...

I am no legal expert, but I would imagine that selling Kombucha would be much easier than selling beer/wine, provided that your alcohol stays below .5% (and it is thus technically non-alcoholic). I would try to find a local Kombucha producer and ask them what laws are applicable. If there isn’t one I assume similar laws would apply to trying to sell any non-alcoholic beverage, so try talking to a small producer of soda, ice tea, or fruit juice.

Best of luck, every time I go into my local Whole Foods there seems to be a new Kombucha, certainly seems like a growing industry.

Alicia said...

Hi. I was wondering if you tried to brew kombucha with hops? Don't hops have antibacterial properties? I'm wondering if that would damage the SCOBY?

Michael said...

I recently got an email about using hops in kombucha, I had similar thoughts about the anti-microbial properties. Here was my response:

Haven't tried it.

Two thoughts:

1st are you thinking of boiling the hops to get some bitterness, or just steeping some for aroma? Generally sourness and bitterness don't blend too well, so I would probably avoid that, but some hop aroma could do very nicely.

Hops were originally added to beer to fend off bacteria (or at least slow it down). I would bet that if you added the hops before fermentation it would effect the ratio of the various microbes. Maybe try adding a few cones to each bottle at bottling, that should give you some aroma and keep the hops from effecting your culture.

Sounds like an interesting idea, if you give hoppy kombucha a try please let me know how it turns out.