What is kombucha?

Kombucha (kahm-BOO-chuh) is a fermented tea drink that probably originated in ancient China over two thousand years ago. The active culture which transforms the tea into kombucha is a complex Symbiotic Culture (or Colony) of Bacteria and Yeast which is held together in a thick, gelatinous polysaccharide matrix biofilm. That’s a mouthful, so it’s commonly referred to by its acronym– SCOBY (SKOH-bee). It is rubbery and slippery, resembling the texture of a squid. It may also be called a kombucha mother, pellicle, zoogleal mat (impress your friends!), biofilm, or mushroom (although that is not quite accurate, because even though the yeast that comprises the colony are in the fungus family, they are not mushrooms).

Fermenting Containers

When looking for a fermentation vessel in which to make kombucha, select a non-porous, non-metallic material. Glass or ceramic work best. Plastic is okay (I occasionally use large beer brewing buckets), but some people prefer to avoid all plastic when fermenting. The SCOBY organisms need air. The wider the container, the bigger the SCOBY can grow. When considering the diameter of a vessel, think Texas, not Manhattan.

Brewing Safely and pH

pH, is one (but not the only) measure of the acidity of a substance. Beverages such as kombucha need to have a pH of 4.6 or lower (determined by the U.S. FDA) in order to be safe to consume (i.e., keeping pathogenic microbes out of the brew). When you start your brew, sweet tea has a pH of about 5. In order to make the brew safe (that is, less prone to pathogenic microbes), you need to decrease the pH (that is, make it MORE acidic) to at least 4.6 at the beginning of the fermentation. That’s why it’s important to add mature kombucha to the starting tea. Once fermentation starts, the pH will continue to lower.

The pH of finished kombucha should be around 3 to 3.5. The longer you let it ferment, the lower the pH. At some point, when all the sugars are converted to organic acids, and it tastes like vinegar, kombucha usually settles on a pH of around 2.7. If you’re brewing at home, you can use pH strips to measure pH. It’s not super precise– if you’re brewing commercially or want more accuracy, you will need a pH meter. pH meters  come in all price and quality points. I opt for a handheld unit that also measures temperature (and adjusts pH automatically based on temperature). That’s not to say that you need to measure each batch. As long as you are adding your cup of mature kombucha or so per gallon of sweet tea, you should be in the correct pH range.

Technique and Recipe

Secondary fermentation (aka “Flavor Time”)

After the primary fermentation, flavoring and bottling (aka the secondary fermentation) is when you can really get creative with your ‘booch! You can use any combination of fresh fruit, fruit juice, veggies, ginger or other herbs and spices. Remember: a little goes a long way, but you should still play around with the quantities needed to achieve the desired level of sweetness or strength. Some ingredients will lend more carbonation. To maximize carbonation, keep the bottles within the range of 76-80F. An [amazon_textlink asin=’B00P7U259C’ text=’inexpensive seedling mat’ template=’ProductLink’ store=’fermeclub-20′ marketplace=’US’ link_id=’63b8163f-3f6a-4b89-a825-ff38c35ffb29′] works great– it’s waterproof and can give you the few extra degrees you need when it’s cold in your room.

Kombucha Flavor Gallery

Also check out our 72 Seasonal flavors for inspiration!

Maintenance

Keeping Flies away

You can craft a simple fly trap to lure vinegar flies away from the good stuff.

Read more about flies and kombucha here.

Where to get a SCOBY

• Us! We now sell kombucha SCOBY’s, shipping within the United States
• Online: I got my original culture from Kombucha Kamp and love it! It has made dozens of babies. They ship nationwide, too (Disclosure: I am an affiliate for Kombucha Kamp, meaning I get a small percentage of sales made if you click these links and buy from them).
• Craigslist or local classified ads- People are often giving them away
• Ask for one on our Facebook page (indicating where you are located). Chances are other Fermenters in your area will be happy to give you one.

Storing SCOBY babies/Taking a Break

If you decide to take a break from making kombucha, or you have extras (because a new SCOBY is made each time you make a batch), you can store your SCOBY (always at room temperature– never in the refrigerator!) in a little of the reserved liquid from the last batch you make. It doesn’t need much to survive, just enough to keep it wet. You can even build a SCOBY hotel by adding multiple cultures to a single container into a “hotel”, like so:

How much should you drink?

Kombucha, like any other fermented food, should be taken in moderation. While it is good for us (being a much healthier alternative to soda drinks), it is acidic, which can upset your stomach. It also contains sugar and caffeine (although it is believed the SCOBY consumes most of the caffeine, leaving about 1/4 the amount in an equivalent portion of brewed tea). There can be “too much of a good thing.” I’ve read that 4 to 8 ounces, twice a day (for a max daily intake of 16 ounces/2 cups/500 ml) is a safe limit. Personally, I only drink max 8 ounces/250 ml a day (and not every single day). You’ll have to experiment and pay attention to your own body, and as always, Trust your Senses.

Ready to learn more? Take one of our classes!

Here’s a preview of the self-paced Kombucha Master Class through Fermenters Club Academy. It’s the next best thing to being at our live workshops!