Is your kombucha too vinegary and sour? Or does it ferment more quickly than it’s supposed to? Here’s how to prevent and fix over-fermented kombucha!
This is a question I’ve seen popping up more and more in our Kickass Kombucha Brewers Facebook Group, so today we’re deep diving into the what’s, why’s, and how-to-fix-it’s of vinegary kombucha!
Why kombucha becomes vinegary
In order to troubleshoot over-vinegary kombucha, it’s important to understand why kombucha becomes sour in the first place.
When kombucha ferments for longer, it becomes more acidic. This is because the yeast in the SCOBY eat the sugars and tannins in your kombucha, transforming them into ethanol. The bacteria feed on this ethanol, turning it into acidity and giving kombucha its distinctively tart taste. Finished kombucha usually has a pH between 2.5 and 3.5 (the lower the pH, the more sour it is).
But sometimes the process becomes off balanced or goes to far, and when that happens you get extremely tart, vinegar-tasting kombucha. While tart kombucha is not unsafe (it’s actually filled with even more probiotics), the taste can be too intense for some people.
How to prevent vinegary kombucha
Brewing kombucha is all about the taste balance between sweet and tart. Here are a few ways to prevent your kombucha from becoming too sour:
Don’t let it ferment for too long. The longer your kombucha ferments, the more sour it will become, so your first step in preventing vinegary kombucha is simply to reduce the amount of days in the first fermentation. If you’re doing a second fermentation, end the first fermentation while the kombucha is still slightly sweet because the kombucha will continue to acidify in the second fermentation.
Move it to a cooler spot. Fermentation will go quicker in warmer areas, so you may need to move your fermentation station to a cooler spot. Kombucha should be fermented between 60-85°F (16-29°C).
Fix the balance of yeast. If you’ve tried both of these and your kombucha continues to ferment much faster than it’s supposed to, you may need to adjust the balance of yeast in your brew.
- Remove your SCOBY from the vessel and wash off the brown stringy bits (these are yeast!).
- Steep your tea for less time. The yeasts feed on the tannins in the tea, and reducing these could help control overactive yeast.
- Use a different start kombucha (such as a bottle of store bought) to reintroduce a more balanced colony of bacteria and yeast.
How to fix vinegary kombucha
Let’s say you’ve already let your kombucha go sour and now you’re left with tart kombucha. What can you do to fix it?
Neutralize the flavor with something sweet. You can mix the kombucha with fruit juice, honey/sugar, or pureed fruit (and drink straight from the first fermentation or move to a second fermentation). Sweetness acts as a counterbalance to sourness.
Water it down with carbonated water, a soft drink, or even plain tap water. This helps make the tartness more palatable without the addition of sugars.
Ways to use sour kombucha
Worst case, your kombucha is way too vinegary to drink. What can you do with over-fermented kombucha?
Use it as a strong starter kombucha for your next batch. I like to keep a bottle of starter in the fridge as a backup (in the event of mold, or if I want to share some starter with a friend).
Make vinegar by letting the kombucha continue fermenting to the point that it tastes like vinegar. Use kombucha vinegar anywhere you would normal vinegar (like in salad dressings, mayonnaise, as a pickling brine, or even as a household cleaner).
Use it as a marinade for proteins or veggies.
Soak grains to make them more digestible.