Note from Shannon: Please welcome Julie Feickert, Cultures for Health Founder and Cultured-Kitchen Keeper.
I tend to crave fermented foods in phases. I’ll go months where I can’t seem to drink enough water kefir. Fast forward a bit it’s kombucha, or sauerkraut, or Greek yogurt. A while back I started to crave kombucha again. I dutifully bottled up four dozen bottles of freshly fermented kombucha and organic juice, drank a few bottles and promptly lost my craving. Leaving the bottles to hang out in the increasingly warm garage.
A few months later I found them. Whoops! I grabbed a bottle I placed a towel over the top, applied downward pressure and opened each bottle. Let’s just say the towel and the pressure kept me from having to clean the ceiling multiple times. Four months of fermentation with added juice yielded a few interesting results…
First, I noticed that while all the bottles had developed significant levels of carbonation, whether they were bubbling out (resulting in losing half the contents in many cases) or whether they just had a nice carbonated texture really depended on the juice I’d used.
More specifically, juice with relatively high sugar content produces a lot more bubbles. Not surprising of course since the sugar is consumed by the still active yeast and bacteria (even after the scoby has been removed) and creates carbon dioxide. In particular, the bottles containing 100% cranberry juice (very little sugar) to flavor the kombucha fared the best in terms of not spilling most of their contents into the sink. My favorite flavoring, pineapple juice, didn’t do so well.
Second, I noticed that the bottles with more sugary juice (such as my beloved pineapple) had over-fermented. Apparently I have developed a skill for making something that tastes a whole lot like beer—and not the more pleasant varieties! So down the sink went quite a few bottles.
Now you may be asking yourself why over fermented kombucha in this case tastes like nasty yeasty beer instead of, say, vinegar.
If you leave kombucha on the counter with the scoby too long, you get something that taste like vinegar and can be used to replace vinegar in recipes. But the addition of the juice in this case fed the active yeast and bacteria in the kombucha. Combined with the warm environment, the yeast and bacteria continued to grow out of control with plenty of new sugar to keep them fed and happy. These bottles all contained a ratio of around 1 part juice to 3 parts kombucha.
Juice has a very high concentration of sugar (with the exception of the pure cranberry juice) and that much sugar actually has the ability to form a fairly significant level of alcohol. Frankly though, even if you want to create alcohol, this isn’t the way to do it. Not pleasant tasting at all! Remember, adding juice for a second fermentation won’t produce any significant amount of alcohol if you are consuming them in a reasonable amount of time. In this case I was thinking Eric and I would each drink a bottle a day meaning the four dozen bottles would have been consumed in just a few weeks. Four months in a warm garage is what did us in.
So what should you do if you ever find yourself in this position with bottles of over fermented kombucha?
First, open with care using a towel over the top and downward pressure. Let them bubble over in the sink until they stop. Second, smell them. If they smell like kombucha, great, odds are good they can be consumed. If they smell like yeast or beer, might as well dump them out and get a head start on washing bottles.
We all have a batch of something here and there fail for one reason or another not taste good. It’s okay! These learning experiences only help us figure out better ways to do it next time.