Bacteria and yeast (the SCOBY) need sugar and tea for proper fermentation – the sugar acts as food, providing energy, while the tea is a natural multivitamin.
Only tea that comes from the plant Camellia senensis provides the necessary nutrients for your SCOBY. Green, black, white, oolong, and pu-erh (fermented black) teas come from the Camellia senensis plant and are all good choices for brewing kombucha. This means no herbal teas or red teas. Teas with added oils (Earl Grey, Chai) or flavors should be avoided. Oils will collect and remain at the top of the brew, interfering with your SCOBY’s growth and fermentation.
Black Tea provides the highest concentration of purines, which aid in the metabolism of microorganisms. The higher the purine level, the more active your culture. Therefore, black tea tends to be present in most kombucha tea blends. Black tea is Camellia senensis leaves that have been picked, withered, rolled, and allowed to completely oxidize. It is known to create a strong apple-cider flavor in kombucha, with earthier tones, and a dark, golden color.
Green tea leaves are picked, lightly steamed (to prevent oxidization) and then dried. These tea leaves give a milder and softer flavor profile than that of black tea. Though you could brew with green tea alone, it seems a safer move to integrate some black tea to allow for higher purines and more thorough fermentation.
White tea is the tiny, young buds of the tea plant. They are picked and slightly toasted before drying. This young tea makes a much milder-tasting kombucha, even lighter than green tea.
Oolong tea falls somewhere between green and black tea. Oolong leaves are picked and withered, but only partially oxidized. This tea leaf will give you a delicate, complex flavor that is lighter than black tea, but bolder than green.
Pu-erh tea is black tea that has been pressed into a brick or ball, then allowed to ferment in underground caves. Its flavor is mild, but very fragrant. Some say this tea brings a pleasant sweetness to their kombucha.
Putting together your kombucha blend
Our Kombucha Kit uses a blend of green and black tea, about 60:40. This blend allows for thorough fermentation, but a much lighter flavor than an all-black starter sweet tea would provide. Purchasing organic, loose-leaf tea as we do for our kits is crucial to avoid tea leaves which have been chemically treated.
If you choose to create a custom sweet tea blend for your kombucha, follow this standard recipe:
- 4-6 tea bags or 4-6 teaspoons loose-leaf tea
- 1 gallon cool, chlorine-free water
- 1 cup sugar
While choosing teas for your blend, do attempt to choose teas that have a similar steep temperature and time. Steeping teas too hot or for too long can completely alter their flavor, leaving you with grassy or bitter sweet tea and later, kombucha.
Caffeine in your kombucha
If you feel concerned about the caffeine levels in your kombucha, don’t be. The caffeine levels in kombucha decrease during fermentation by as much as a third within 24 hours, and between 50 and 65 percent after seven days.
Although caffeine levels will vary depending upon the quality of tea, tea type, steep time, and fermentation, kombucha brew contains very little caffeine.
If you were hoping to brew with a decaf tea blend, we would not recommend it. Most decaf tea blends, even “natural” ones, have been chemically treated.
You now have all the tools to begin experimenting with your own sweet tea starter for your SCOBY. Find the right flavor by blending different tea ratios with each batch.