Written by Anthony Zunino, photographed by Philip Gunderson
There’s a gelatinous colony of yeast sitting on my desk doing crazy things. I like to think of it as a pet, similar to a humble goldfish or succulent. It’s a wrinkled beige blob, with strings dangling down into the jar of liquid on which it feeds. This is Stanley, my SCOBY. Stanley makes kombucha, a carbonated slurry of yeast tasting somewhere between sweet tea and vinegar, for which many people will pay upwards of five dollars a bottle at the grocery store.
Although unique in its own right, kombucha is part of a large family of fermented beverages containing live, active cultures. A great variety of things gain their unique flavor through fermentation, including pickles, beer, sriracha, mustard, sauerkraut and more. The sour funk of fermented food and drink has been utilized in cooking for millenia.
There are a huge variety of fermented beverages out there. Let’s first review the process of fermentation through the context of kombucha, before moving on to other types of cultured creations.
Once relegated to natural foods markets and the occasional home brewer, kombucha has since made its way into the mainstream, but for many this fermented beverage remains undrinkable. With strong notes of vinegar, floating chunks of yeast, and a general flavor far afield from conventional beverages, it makes sense that a modern palate accustomed to soda and beer might not enjoy it. If you’ve tried kombucha, you probably know what I mean.
I didn’t like kombucha at first. Now, I brew two gallons a week of it in my apartment. Being cheap, endlessly customizable and easy to make, brewing kombucha is a fun way to get creative in the kitchen, and to strengthen your gut bacteria.
The Fermentation Process
In many cases, fermentation acts as a form of preservation. In the case of kombucha, however, the chemical processes at work are constantly bringing the liquid closer to becoming vinegar. This tendency to become unbearably sour in a matter of days is part of what makes kombucha so expensive. For the home brewer, though, the only ingredients required are sugar, tea leaves, water and time.
Kombucha’s gradual souring is caused by a Symbiotic Community of Bacteria and Yeast, better known by the abbreviation SCOBY. The SCOBY is the alien-like formation which forms on top of the tea, breaking down sugar into alcohol, and then alcohol into acetic acid. Acetic acid is the active ingredient which gives vinegar its sour flavor, and it does the same for kombucha.
After anywhere from a week to a month of initial fermentation, kombucha can then be transferred into sealed glass bottles to undergo a secondary fermentation. By sealing the bottles, carbon dioxide produced by the fermentation process is trapped and dissolved into the liquid, creating carbonation. After just a few days in a sealed bottle, kombucha becomes explosively fizzy.
Sometimes I leave the kombucha to carbonate without any added ingredients, but usually I use this time to flavor the brew. Any combination of juices, fresh fruits and herbs can be used to flavor kombucha. Ingredients with a high sugar content, like fruit juices, will lead to a more rapid fermentation, and therefore a more aggressive carbonation. Simply add a few ounces to the bottle and leave it to ferment. My preferred kombucha brew is beet juice with cayenne pepper, lemon juice and a few chunks of ginger.
Cultured beverages like kombucha are also believed to provide a variety of health benefits. The fermentation process enables the growth of a variety of probiotic bacteria, microbes shown to promote good gut health by increasing the diversity of living organisms in the digestive system. Similar bacteria are found in things like yogurt, kimchi and miso.
Although probably the most well-known probiotic beverage on the market, kombucha is not the only cultured drink out there.
I personally have taken to brewing my own ginger beer, a drink rarely encountered in its live, cultured form. The fermentation power in this recipe comes from a ginger bug, a bacteria and yeast colony which takes about a week to grow using the cultures which exist naturally in the ginger root. This bug can be thought of similarly to a sourdough starter, kickstarting sweet ginger tea’s transformation into carbonated ginger beer. Ginger beer can be brewed so that it is much drier and healthier than the store-bought version, and the live cultures which it retains give the drink a tangy and yogurt-like flavor.
By far the easiest fermented beverage that I’ve brewed, however, is a Mexican recipe called tepache. Tepache does not require a SCOBY or starter of any form. Rather, yeast that is naturally present on pineapple skin powers the fermentation process. Ginger, cinnamon and habañero give this drink a spicy flavor, while piloncillo and pineapple act as the sugary fuel for the reaction. Try it yourself!
- 1 large pineapple
- 1 habañero pepper, sliced in half
- 8 ounces piloncillo (Mexican ingredient found near the sugar at Tropical Foods) or brown sugar
- 1 palm-sized piece of ginger, sliced
- 1 cinnamon stick, broken in half
- 3 cloves
- 1 gallon glass jar with airlock (the airlock is necessary to prevent gas build-up and explosion -> what does an airlock look like?)
- 6 fermentation-grade glass bottles (optional for carbonation)
- Leaving the rind on, cut the pineapple longways into fourths. Use a knife to remove about a half inch of the core from each \\piece. Cut the pineapple into chunks and add to the jar.
- Add habanero, piloncillo, ginger, cinnamon, cloves, and a splash of water. Muddle using a wooden spoon to release some juices from the pineapple.
- Top off the mixture with water, tightly screw on the lid with the airlock, and leave to ferment in a warm part of the house for 48 hours, 72 hours if choosing not to carbonate.
- After first fermentation is complete, strain all solids from the liquid. If carbonating, pour into fermentation bottles, leaving about an inch of head space at the top for gas buildup. Seal and leave to ferment for another 24-36 hours.
- Refrigerate immediately to halt the fermentation and prevent overcarbonation. Serve over ice by itself, or with a splash of good tequila.