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.
I am making kombucha for the first time. The lady I got the SCOBY from said it, and the starter it was in was enough for 5 litres. I could only find a glasjar 3.6 l, so I made strong tea, put in organic raw sugar, let it cool and put in the SCOBY and starter and now after 11 days I think it is too vinegary. Also slightly alcoholic as I thought I had a mild buzz after just tasting it (yes I’m a light weight :)). Anyway, what was the problem? It is supposed to take three weeks so why is it done already?
It totally depends on your environment (heat will speed it up). But 11 days is very normal, I’ve never done 3 weeks.
3 weeks to ferment? My problem is it becomes too vinegary in 7 days. I got my organic scobie on Amazon and now it grew to be quite large. Maybe I need to rinse off all the brown stuff like the article says. I could try letting it sit for only 5 days? I use one cup of sugar and 8 tea bags like this other article instructed.
All of those things would likely help! And reducing the fermentation time 🙂
My kombucha was accidentally left in F1 for 2 weeks… Is it still ok to use as a starter for new kombucha and scoby hotels?
I would give it a taste! If it’s too sour to drink then go ahead and user it as starter. If it tastes good, bottle it up! 😀
Hi Sarah, I just made my first scobies (!) By the time they were done, the resulting liquid tasted sour, vinegary, and musky. I’ve had this musk pop up for me when doing first fermentations before, but have been unable to figure out what it is… any thoughts? I’m fairly certain I didn’t have mold, I’ve looked at as many moldy scoby pics as I can.
(Btw the scobies brewed over 3.5 weeks, at 70-73F, in open air.) thank you!!
It sounds like it could be an unbalance of yeast in your brew! Perhaps try adding a bit of kombucha from another fermentation (or store bought) to help bring the balance back?
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!
Hi Sarah, for all the newbie’s like me. I had my third batch of kombucha and been the proudest dad ever as my family didnt drink my friends kombucha but they loved mine. I use “rooibos” tea(translated as redbush tea) a south african tea and like a said, kids loved it. Yet this morning, tasted my kombucha and ohh my, as sour as vinegar, yet its been 5 days as all my other batches was left for at least 10 days. came here, read about sour kombucha and went back to see if i can “save” it-however, after taking my scoby out and stir my kombucha, I tasted it once more, to try and figure out how much water or tea to add, and to my surprise not sour even a bit! I came to the conclusion that the vinegary parts stay afloat and in the upper level of your brew, thus, just dipping a spoon in and tasted it, produced the “sourest” part of the mix, yet, after stirring, it was completely balanced out. Note to self: when you read stir before tasting it, you should maybe stir before tasting it and saving you from throwing a perfect batch down the drain. Love your site!
You are completely right Rubin! The pellicle is the cellulose disc that grows on top of your kombucha which is made by certain bacteria, and those bacteria are responsible for producing acetic acid which is the organic acid that gives the vinegary flavor.
My mom bcuz 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 so I can gave my good flavored mom urge?
Can I drain some off and add sweet tea and let it go for a couple if days the flavor it. My sister us allergic to smell of vinegar so I can’t use it for vinegar. But I do not want to toss it out because it us too vinegar to drink. How do I temper it down so I can continue to make drinkable mom urge?
Thanks
You can temper it down with some tea or juice (or even soda water). Or instead of tossing it, just use it as a starter kombucha for your future batches 😀
I just want to say how much I love, love, love making kombucha. I have “purchased” Sara’s guide to making kick ass kombucha and have been very successful with it. I hope that you all contribute to her cause!
My 3 yr. old granddaughter waits anxiously for me to bring her kombucha when I visit. First question when I walk in the door is did you bring me kombucha? So adorable! She loves it! Can’t wait to make it with her. What a fun project for little ones:)
Aw I’m so happy to read this, Penny! I love when it becomes a whole family affair 😀 Happy brewing!
Its my first time making kombucha and started brewing. It’s on its 5th day of brewing and noticed the scoby is still at the bottom and there’s a lot of bubbles on top. Is that normal?
Yep this is normal! SCOBYs may sink or float around, doesn’t matter where they decide to hang out 😀
Oh my goodness! I should have read this area before throwing out my second batch! Oh well, now I know. Thanks!!! :0)
Mine got a bit sour and I thought it might be because I added a heat source since my jar collection increased and it is cooling down for winter. Seemed that my 6-7 days to F1 became 5 days and a bit sour. Now I’m moving things along faster. I do F2 in gallon jars for flavor then strain and bottle for F3. But I have a baby scoby in every bottle and have to strain (I don’t like jelly bits in my drink). How can I slow the baby scoby production? I F3 for 4 days on heat at 80F.
I’m afraid you can’t really slow down SCOBY production – it’s a sign of healthy kombucha!
Thank you for all your great advise on this. I’m still learning and developing my brew techniques. Hey. Maybe I’ll start making wine or beer. =) hehehe
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. I have tried filtering for 2nd fermentation. But within a week I have either a baby Scoby in my bottle or again loads of sediment. Help
Kind Regards and many thanks
Rob
The cloudiness (and sour taste) are from over active yeast. Try removing the brown stringy bits and adding a new bottle of unflavored kombucha (from the store) to help balance out the bacteria and yeast! 😀
Sarah, I do continuous brew with a tap, and I always leave a little of the old brew in the jar, with the scoby (after I remove a layer of the scoby, and add the new tea. I also have this problem with cloudy brew (though didn’t know this is a problem), and new baby scoby in each bottle during 2nd ferment. When you say to add a bottle of store-bought, would that be in addition to the leftover brew, or should I completely empty my jar and start fresh with the store-bought in my next batch?
I’d probably empty it completely so you can reintroduce a totally new colony of bacteria and yeast!
HI Sarah,
I really appreciate all the work you put into your website, and I always love reading the interesting information you provide. I have used your site for over a year and I love it . keep up the great work!
cheers
ron
So happy to hear it, Ron! 😀
The other cause can be too many scobies/ pellicle mats. It seems to speed up the process
How many is too many?