Small batch kombucha typically goes through 2 fermentation processes before you drink it. During this transformation, the sweet tea you begin with turns into fizzy kombucha with a myriad of health benefits for the mind, body, and gut.
Only a couple of ingredients are needed to get the fermentation process going: black tea, sugar, a symbiotic culture of bacteria and yeast (a.k.a. a SCOBY), starter liquid and water. Kombucha fermentation is fueled by sugar and caffeine in your tea, and your final product will have only trace amounts by the time it reaches your glass.
The first fermentation (F1) is the process in which bacteria and yeast break down the added sugar and metabolize it into acids and carbon dioxide. The fermentation has aerobic and anaerobic processes, so the fermentation vessel needs to be covered for protection, but not sealed to allow air flow. The longer you allow the first fermentation to go, the more sour and vinegary the tea will become. We generally recommend allowing F1 to last between 7-10 days when batch brewing.
The second fermentation (F2) occurs after the SCOBY is removed and fruits, herbs & spices are added to flavor the kombucha. During this time fermentation happens again at a slower rate. The tea will continue to become less sweet as it absorbs the flavor profile and color of the flavoring agents and the yeast continues to feed off the remaining sugar & fruits. We recommend doing your F2 in a sealed bottle or jar, and placing in a dark space with little airflow for optimum flavor. To put an end to F2 and get that booch ready to drink, after 2-4 days of fermenting and absorbing flavor, move your brew to the refrigerator!
Brewing kombucha depends on a balanced, symbiotic relationship between the bacteria and yeast that leaves you with a sweet and tangy tea. High quality ingredients are the key to maintaining balance. Additionally, finding the optimum number of days for each ferment that pairs with your unique taste buds and preference of sweet and sour! A well rounded brew is fairly easy to come by, but may take some experimentation. If you haven’t found your perfect brew try out our 3 personal preferences:
Briana: 10 days is my magic number. Depending on how my week goes, I do a 7 or 8 F1 and 2 or 3 F2 for a grand total of 10 days of brewing from start to refrigeration. I live in a warmer climate and do not add days in cooler temps.
Brooke: I prefer a 12 day fermentation. I usually do a 7 or 8 day first ferment and I always do a 4 day second ferment. To me the different between 3 and 4 day F2 is significant! In the winter when my brew is in the low 70’s I do a 10 day F1.
Brittany: My ideal brew time is 11 days, I like to do an 8 day F1 & 3 day F2. It’s still slightly sweet, and perfectly bubbly. I don’t always have time to brew on day 8, so sometimes I go a little longer, but unless I am out of my stash, I always do a 3 day F2. In the colder months, I always extend both fermentations by 1-2 days for optimal bubbles.
Try your own experiments in fermentation. We always recommend to new brewers to stick one bottle in the fridge after day 2, 3 and 4 of F2 to see what you like best! When experimenting with kombucha in anyway, we also recommend keeping a SCOBY Hotel. SCOBY Hotels are an easy way to store your extra SCOBYs in case something goes awry in your brew. If you should ever need to start over, you’ll have a fresh SCOBY and starter liquid ready to go!