Home Plate: Making your own kombucha
Last fall, I gave a talk on feeding the good bacteria in your gut by eating probiotic foods, like yogurt. Afterward, a woman in the audience introduced herself to me and asked if I would like to learn how to make the probiotic beverage kombucha.
As it happened, making my own kombucha was on my list of DIYs I ought to try. If you haven’t had this yummy, refreshing beverage, it tastes like a cross between iced tea and citrusy ginger beer – a slightly sweet, tart, bubbly thirst-quencher that is absolutely addictive.
Making kombucha is a little like making beer, though the finished product has only a tiny amount of alcohol in it – not enough to get tipsy by a long shot. A strong brew of tea and sugar is cooled then mixed with a sweet tea-loving “symbiotic colony of bacteria and yeast” – SCOBY for short.
Left at room temperature for a week or two, the SCOBY, which looks like a raft of whitish jello, chows down on the sweet tea, converting it into something that tastes nothing like tea, and is filled with good-for-you substances, among them five different B vitamins and the powerful antioxidant gluconic acid.
But store-bought kombucha is pricey. And to make it, you need a SCOBY. These can be ordered online from several reputable operations that sell kombucha start-up kits, but again these are expensive. The best way to get started is to find a friend who has a SCOBY going and take home a piece of it. And so I found myself driving to Concord, for some hand-me-down SCOBY, provided by that generous, helpful kombucha maker who had attended my talk, Tatiana Lassonde.
Lassonde handed me a jar with something that looked like The Blob in it floating in an amber liquid. She even gave me a recycled one gallon glass jar for a fermentation vessel. And of course, she gave me her recipe.
Since then, I’ve brewed many batches of kombucha, handed SCOBYs off to friends, and even converted my skeptical husband into a kombucha lover.
All sorts of health claims are made for kombucha – it’s reputed to be a great hangover cure for one – but I love it for its flavor. That said, it is known to be a diuretic and is full of probiotic microbes, so it’s best to drink it in moderation, or at least to drink lots of plain water, too.
And do keep in mind that you will need to be careful about cleanliness when brewing kombucha. Boil your water first, to make sure there are no contaminants in it. And be very sure to use only glass or other lead-free, non-reactive vessels for fermentation – the finished product is acidic, and could leach heavy metals from inappropriate materials.
12 to 14 cups filtered water (chlorine-free, use the larger amount of water if you don’t have any kombucha to use as a starter)
1 SCOBY, stored in kombucha (either purchased or from a friend)
1 to 2 cups leftover kombucha (from the stored SCOBY or your last batch of kombucha; optional, but helpful)
5 to 6 tea bags or about 1/4 cup tea; choose from unflavored, caffeinated black, green, or white teas (black is supposed to work best – about half the caffeine will be lost during fermentation)
3/4 to 1 cup sugar (I like to use organic sugar; don’t substitute other sweeteners, at least until you have some experience making kombucha – most of this will disappear during fermentation)
You will also need:
a strainer (if using loose tea)
a tea pot
a 1 gallon glass jar, or 2 half gallon glass jars, very clean
rubber bands, paper towels or cheesecloth for covering, also very clean
Brewing the Sweet Tea Starter: Bring half of the water to a boil. Meanwhile, put the tea bags or loose tea into a tea pot; cover with the water when it has boiled. Let the mixture steep until it becomes a pot of very strong tea.
Pour the tea into a large, heat proof bowl – using the strainer if you steeped loose tea – and stir the sugar into the hot tea. Don’t discard the tea, but return it to the tea pot.
(Note: The larger amount of sugar usually makes the kombucha ferment faster and creates more bubbles. Most of the sugar will be metabolized by the SCOBY during fermentation, so more sugar doesn’t necessarily mean that the kombucha will wind up sweeter, unless you choose to begin drinking it while it is still sweet.)
Boil the rest of the water and pour it over the once-brewed bags or loose tea to brew a second pot. When it has steeped for several minutes, add the tea to the bowl of cooling sweetened tea and set aside to cool. It is essential that the tea be no warmer than around 95 degrees when poured over the SCOBY or the heat may kill it.
Adding the SCOBY and fermentation: Put the SCOBY into the clean gallon jar along with the 1 to 2 cups of starter kombucha. If using two jars, cut the SCOBY in half (use a pair of sharp, clean scissors – the SCOBY is surprisingly tough and can’t be easily torn) and place half the SCOBY and half the starter kombucha in each jar.
Pour the cooled, sweetened tea into the jar(s), swirl it around a little, and then cover the jar(s) with a piece of paper towel or cheesecloth held on with a rubber band.
Store the fermenting kombucha in a warm place out of direct sunlight. The SCOBY will begin to grow, looking like a white gelatinous raft floating on top of or in the middle of the kombucha. Stringy pieces of brown yeast will hang from the SCOBY – this is perfectly normal – and bubbles will form.
The kombucha will be ready to drink, depending on ambient temperature and how much sugar was used, in 1 to 2 weeks, more or less. You can begin tasting it during the first week, and bottle it when it suits your taste.
Bottling and Storing Kombucha: When you like the way the kombucha tastes, remove the SCOBY, put it into a clean jar, pour some kombucha over it, cover it with a lid and refrigerate it until the next kombucha brew. When using the SCOBY again to make more kombucha, peel the newly-formed, white top off of the brownish older SCOBY. Discard the older SCOBY (a compost pile is a terrific place for it) and use the newer SCOBY for the new batch.
Strain the remaining kombucha through a clean, fine sieve to remove any strands of yeast, then pour it into clean glass bottles, leaving a bit of room for bubbles at the top.
I think the safest way to close the bottles is with corks, as these will pop out should too much carbonation build up. You may also use growlers with swing-top lids, the kind purchased for refilling at breweries. Some people use plastic soda bottles with screw top lids, as these can hold a considerable amount of carbonation.
If desired, leave the filled, sealed bottles at room temperature for another day to build up carbonation, then refrigerate, which will slow fermentation almost completely. Cold kombucha will keep for a few months.
Flavoring Kombucha: Kombucha may be mixed with all sorts of flavorings once it has fermented. Try flavoring yours with fruit juice, for example, or fresh ginger. Store refrigerated.
Cooking with Kombucha: Kombucha can be used in the same way you’d use a tart citrus juice, in a mixed drink, say, or as a cold soup base. Kombucha that has soured to vinegar can be used just like any other vinegar.
Keep in mind that used cold kombucha will maintain its probitotic properties. If it is heated, though, many of the beneficial microbes it contains will be killed.
Below is a recipe for an Asian flavored tart-sweet slaw that uses raw kombucha; it’s especially delicious paired with rich meats, such as pork belly, duck or ribs.
Kombucha, Mango and Cabbage Salad
1 small green cabbage, cored and thinly slice
1 slightly under-ripe mango, peeled and cut into matchsticks
2 or 3 scallions, trimmed and finely chopped, both green and white parts
1 small knob of ginger, peeled and grated (about 2 teaspoons; use more or less to taste)
3 tablespoons or so of chopped fresh herbs; a mixture of mint, cilantro and basil is good, plus a few nice herb leaves for garnish
1/2 cup kombucha (use 1/4 cup or less if your kombucha has become vinegary)
juice of a small lime (about 1 tablespoon) 1 tablespoon rice wine vinegar (add more or less to taste)
1 tablespoon fish or soy sauce
1 tablespoon sugar
1 teaspoon toasted sesame oil (more or less to taste)
1/2 teaspoon ground hot red pepper or a squirt of sriracha (more or less to taste)
1/2 teaspoon of salt (or to taste)
Toss all ingredients together. Taste and adjust seasonings, if desired. Serve immediately, or chill to allow the flavors to meld for an hour or two. Garnish with herb leaves and an additional sprinkle of red pepper, if desired.
Makes 6 to 8 side servings.