Photo: Sara Tane

Can't stop yourself from buying $5 bottles of kombucha at the health food store? Curious about just what goes into making it? Well, save yourself money and know exactly what's in your new favorite fizzy beverage by DIYing the fermented tea. These simple step-by-step instructions will walk you through everything from purchasing equipment to bottling your finished product. 

December 20, 2016

If you're riding the kombucha bandwagon, you're in good company. The trendy probiotic drink is exploding in popularity, with new brands and exciting flavors filling the refrigerated shelves at more and more stores. Along with classic fruity flavors like Gingerberry and Asian pear, you'll also find more adventurous offerings like turmeric-beet, mango-habanero, and verbena rose.

What is Kombucha?

If you're not familiar with kombucha, let me back up just a minute and explain what it is. Kombucha is basically a probiotic-rich fermented tea beverage. It's fizzy, with a lightly sweet, tart flavor that is just irresistible. It has risen to fame mostly because folks are becoming more and more interested in gut health, and with that an interest in gut-healthy probiotics. And guess what kombucha is full of? That's right—gut-friendly probiotics (aka good bacteria).

Now, while you can certainly buy kombucha almost anywhere these days, here's the catch with that: It's pretty dang expensive. By the time you add tax, each bottle (typically 16 ounces) will run you about four dollars. If you like to drink a bottle a day (as I and many, many others do), that'll run you $28 per week, or $112 per month. And that, my friends, is why I started brewing my own; it was too expensive of a habit to maintain.

And I'd love to encourage you to do the same. Aside from saving money, brewing your own kombucha puts you in touch with and teaches you first-hand about the magic of fermentation. You get the privilege of watching (and tasting) your concoction change as bacteria and yeast eat the sugar in your tea mix (more on this in a minute), and the flavor changes from sweet to tangy, with just the right hint of yeasty, beer-like funk in the aftertaste. It's incredibly easy to make, only requiring a little initial investment in equipment and the patience to allow the fermentation to happen. And you can use our recipes to create your own fun flavors. Here's what you need to know to get started:

The Equipment

  • A large glass jar or two for fermenting. For safety reasons, do not use ceramic. I go for gallon-sized, but you can try smaller sizes for petite batches, especially if you're just starting.
  • Bottles for portioning and further fermenting. You either buy some (I like and use 16-oz. swing-top bottles), or save and wash your purchased kombucha bottles or sturdy BPA-free plastic drink bottles (I use Gatorade bottles). Bottling at least one portion in plastic is particularly helpful for reasons I explain below.
  • A funnel
  • A bottle brush (here's a set that contains bottles, funnel, and bottle brush)
  • Some standard coffee filters or paper towels
  • A rubber band
  • Dish soap that's NOT antibacterial—for cleaning your jar and bottles each time

The Ingredients

  • Tea: Plain ol' black tea (like for making iced tea) works great, as does green tea.
  • Granulated Sugar: Honey and other sweeteners don't do the trick; regular sugar is what you need. Don't worry—the bacteria eat much of the sugar during fermentation, so you end up with not much residual sugar in the end product. (That's why the finished kombucha doesn't taste very sweet.)
  • Water: I use tap water; if you don't trust your municipal water, use filtered.
  • SCOBY: This guy needs a little explanation. SCOBY is an acronym that stands for symbiotic culture of bacteria and yeast. It's the "mother" that you use for every batch of kombucha you make, and it looks like a round, flat, opaque-beige piece of agar agar (like what was in those Petri dishes in chemistry class). You can order a SCOBY, or you can make your own; directions for making below. But you have to have one in order to brew kombucha. Whenever you brew a new batch, a new layer grows onto the SCOBY; it's easy to peel off, so you can use it to start another batch for yourself, or you can give away 'baby' SCOBYs to friends who want to get started.
  • Unflavored Kombucha: You only need a little bit, 2 cups for a gallon-sized batch.

 Photo: Kelsey Hansen

To Make Your Own SCOBY

If you want the full-on DIY experience, you can make your own "mother." I'm giving directions for a gallon-sized jar, but you can cut the ingredients in half for a half-gallon jar.

Ingredients:

  • 8 cups water
  • 1 cup granulated sugar
  • 8 regular-sized tea bags (black tea or green tea)
  • 2 cups unflavored kombucha (such as this one)

Directions:

  1. Bring water to a boil in a large saucepan. Add sugar, and stir until sugar completely dissolves. Turn off heat. Add tea bags, and allow mixture to come to room temperature (add ice to speed this process if you're in a hurry).
  2. Pour kombucha into a 1-gallon-sized jar. Add room-temperature tea; do not add hot tea, as it will kill the good bacteria. Add cool water to fill jar to the top, just where the mouth starts to narrow. Cover jar with two coffee filters or a double layer of paper towels, and secure with a rubber band. Place jar in a place, at room temperature, where it won't get jostled and it's out of direct sunlight; it does not need to go in a dark place, just out of direct sun.
  3. Wait. It will probably take 2 to 4 weeks for your SCOBY to form. You can lift the covering to see what's happening—just try not to slosh the liquid at all. At first, nothing will happen; then, after a few days, you'll see some bubbles forming on the surface. Then you'll see more and more bubbles, and maybe a thin, clear jellyfish-looking blob on the surface. Once the blob covers the surface, is opaque, and is roughly ¼-inch thick, you have a viable SCOBY. Congratulations!

 Photo: Kelsey Hansen

The Basic Steps of Making Kombucha

First Fermentation: For this initial step, you're working with a big batch of tea, in your big jar. Follow the tea brewing instructions as listed in the making a SCOBY recipe above, allow to cool, and add the 2 cups (if you're making a gallon-sized batch) of unflavored kombucha. Fill jar with cool water to just where the mouth starts to narrow. Float your SCOBY on top. If your SCOBY sinks, don't panic. Give it a day or two; it should rise to the top. Cover jar with 2 coffee filters or a double layer of paper towels, and secure with a rubber band. Allow to ferment at room temperature, out of direct sunlight, for 7 to 14 days, until it tastes pleasantly tart and not too sweet. (Think of the store-bought kombucha you've enjoyed; try to match the way it tastes. The longer the tea ferments, the more sour it will become.) The amount of time it takes for this first fermentation depends on the warmth of your "room temperature."

Second Fermentation: For this step, you'll be bottling individual portions of kombucha and resting those for a few days; this is when carbonation happens. Get your large jar of tea, remove the covering, and (with clean hands) gently remove the SCOBY to a plate. Set aside 2 cups of this kombucha (for a gallon-sized batch) to serve as the starter for your next batch. Pour remaining kombucha through a funnel into your bottles. Add flavorings as you like; see our specific recipes.

TIP: Pour at least one portion of kombucha into a sturdy plastic bottle; this will help you gauge carbonation. Once you've dispensed all the kombucha into bottles (including one plastic bottle), allow these to sit at room temperature, out of direct sunlight, for anywhere from 3 to 10 days. Initially squeeze the plastic bottle; it will have a lot of give. Keep squeezing the bottle every day or so; when it has little give left, when it's nearly rock-hard, you know that you've achieved carbonation. At this point, get all your bottles in the fridge; the cooler temps will practically stop any further carbonation from happening.

For lots more on the science, safety, and everything else regarding fermentation, I highly recommend checking out The Art of Fermentation by Sandor Katz.