Take malted grain, add hot water, wait, drain it off, and you’ll have wort. Add yeast, and fermentation will occur as the yeast consume sugar and produce alcohol and CO2. Distill that and you’ll have whiskey. Instead, wait for carbonation to build up and you’ll have beer. Instead of adding yeast, leave the fermenter open and allow wild yeasts and bacteria from the air in a certain area of Belgium to do their thing, and you’ll have lambic beer. Make that with raspberries and you’ll have framboise.

That pretty much covers alcohol. The fun is of course in the details of grain/sugar choice (e.g., agave for tequila), its preparation (e.g., peat), flavoring elements (e.g., hops), distilling & aging practices (e.g., barley plus corn might become a beer, or a bourbon), etc.

But the Boing Boing post was actually about Kombucha, another form of fermented beverage, involving a symbiotic organism of unknown origin, “a polyculture of at least two yeasts and two bacteria, living synergistically.” So says Paul Stamets’ Kombucha page, where he warns of the risk of contamination in home production, saying, “Making Kombucha under non-sterile conditions becomes, in a sense, a biological form of Russian Roulette. For those who are ill, drinking Kombucha prepared at home could be one of the worst things they could do!” However, this was written in 1995, and Wikipedia suggests the homebrew contamination rate is low, while still advising good sanitation and storage practices and suggesting that those who are ill should be careful.

The risk of contamination was my first thought upon reading how it’s made, either at that Boing Boing Kombucha post, or at any other number of sites, like this Seeds of Health one. As someone who’s brewed beer, it’s astonishingly similar. Basically, put sugar in water, and add microorganisms. With Kombucha, you use brewed tea water. The yeast in your culture turn the sugar into alcohol, which the bacteria in turn ferments to acetic acid (vinegar), so you aren’t going to get drunk. The bacteria also compete for sugar with the yeast, producing some other acids like gluconic acid. You drink it before all the sugar is fermented, so you’re not drinking something as acidic as, say, apple cider vinegar.

Now, with beer, you need stricter sanitation, and airlocking, to eliminate bacterial contamination and oxygen addition. Your yeast need oxygen to grow and multiply at first, but can live and ferment without it, and its presence oxidizes the alcohol and makes your brew taste stale, so you aerate the wort before adding yeast, but then avoid aeration henceforth.

With kombucha, on the other hand, the culture requires oxygen, or else the bacteria will die and you’ll just get alcohol. There’s nothing wrong with kombucha wine, or so I read, but it’s not the typical goal. Most instructions say to cover your container with a cloth to reduce contamination, and obviously many people get great results following simple instructions, but I feel, why not just use some kind of sanitary filter such as is sometime used in other fermentation projects, in addition to using sanitized glass containers for fermentation and storage? There’s always a risk, but why not reduce it if you can?

I will likely try to make kombucha sometime, as it’s a tasty probiotic beverage, and I’m interested in the process. But, having read up on its components, the process, and health & scientific claims, it seems that in general, a healthy person is most likely just enjoying the benefits that any sweet, caffeinated, hydrating beverage provides, and would probably get more probiotic GI-tract benefit from a serving of good yogurt or kefir. Hmm… caffeine and yogurt, my favorite morning routine!

Incidentally, I’d like to add to this post that knowing the makeup of kombucha just makes it more interesting to me. I have a soft spot in my heart for symbiotic microorganisms, my favorite being lichens due to their resilience to extreme conditions. I should also note that lichens are very different from limpets. Alex? [John Hodgman] You’re welcome. [/John Hodgman]

Further incidentally, as to the question of whether one could ferment popcorn, my internet research suggests you could, but it probably wouldn’t differ greatly from pre-popped corn, and be more difficult to manage what with it taking up so much more volume. It might at least be an interesting adjunct in beer (regular corn is very common). Clearly, I’m not the first to think of it.