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.
“I have had this acid problem every time I Brew. Scobies seem to generate at a great rate and I can never seem to get a clean brew. It’s always cloudy or has a great deal of sediment. Help!”
The cloudiness (and sour taste) are from over active yeast. Try removing the…
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.
“AWhen you say, “wash the scoby to remove brown stringy bits”, how do I do that and what should it be washed with?”
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.
“Mine got too vinegar to use for a second ferment and I can’t bottle it as it is too vinegar. How can I get it back so I can use it to do a second ferment?”
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.
This is very helpful thanks. My first batch is very vinegary and little – no bubbles. So I’ve left my second batch brewing for approx 3 weeks. I still have noticed little – no bubbles and I guess this too will be vinegar now. ????????
Hi Jackie! The bubble don’t usually form until the second fermentation, but it sounds like you may still be on the first fermentation? Try bottling it (second fermentation) before it gets too vinegary, then let the bubble form in F2.
When you say, “wash the scoby to remove brown stringy bits”, how do I do that and what should it be washed with? Thanks for all the info on your site!
Just run it under tap water! 😀
I’ve been baffled by my kombucha getting vinegary so quickly. It’ll taste great at the end of F1 but be too sour to drink by the time its done favoring and carbonating. I’ve been asking in FB groups I belong in but no one has suggested that the yeast balance may be off. I will try straining my starter and rinsing/removing the mat… and probably start a new starter too.
I’m a newbie. I have made my first batch and bottled it. What should I do with the scoby? Can I let it sit in the bottle immersed in some kombucha, and just add tea and sugar next time? Or I should take it out and somehow store it (but how?) and wash the bottle thoroughly before making the next batch? Thanks
Yep it can just sit in there! I’d use it to start your next batch right away, but here are ways to store it in case you want to take a break.
Also, I used a recipe with 1/2C sugar + 1/4tsp sea salt per 6C tea +1C starter. At 7 days it was too sweet but at 10 days it was very sour yet also still pretty sweet.
Does that mean I used too much sugar?
As it gets more sour it should become less sweet, but your ratios seem okay. I’ve never heard of using salt in kombucha – maybe omit that?
Great site. Just did my second batch @ 10 days but it is pretty sour, yet very tasty, so I will cut back to 8 or 9 days.
What can I do to get the fizzy effect? Mine is flat . A second fermentation with a fruit puree? Regards.
Yep exactly, a second fermentation in sealed bottles with fruit or sugar. Here are some tips for fizzier buch!
I reawakened a scoby that had been stored in the fridge over winter. I added brewed tea, sugar and let sit …It seemed ok. I did do a second ferment but it isn’t great tasting.
I have a batch on my counter. Its been about a month. Tasted fantastic for a while. Now its so sour my face puckers.
Im not looking to do a second fruit infused fermentation. Is it safe to keep allowing the same batch to ferment on my counter? and feed it sweetened tea water every few days?
Thanks Sarah!
Yep it should still be safe!
I usually let my kombucha ferment too long to be used on its own. Then I mix it 2/1 with unsweetened tea and some fruit pieces for carbonation. Works wonders for me.
I found lightly pasteurized mango juice in the store searching for something to kick-start fermentation again on some kombuchas that got a little too vinegary for me.
I put 1/4 cup of this juice in a 1.4 l bottle about a week ago and there is no fermentation action going on at all. It’s been a little cool around the house lately and I had some kombucha to mix with the mango juice so I just poured the kombucha into the juice plastic bottle and kept it off and put it in my pocket to create some heat to see if I could get some fermentation going on but sadly to say nothing happened as far as fermentation goes. This was my first batch of kombucha that went sour on me. Is the lightly pasteurized juice no good for this application? Or should I use more juice? I can stand the taste of the booch but others probably wouldn’t care for it.
The mango juice shouldn’t be the problem, you might just need to add a bit more!