Learn about the worst homemade kombucha mistakes and how to avoid them. Plus get the kombucha brewing method that works best for me after years of practice.
Homemade kombucha is surprisingly easy to make.
I’ve been brewing kombucha at home pretty consistently for many years now. To get started making homemade kombucha, you need a few supplies (see below), you need to understand the process (I run through my tried and true kombucha brewing method below) and you need time to allow fermentation to take place.
But there are some rookie mistakes that can cause you to ruin the whole batch of kombucha, and worse, your entire scoby. Believe me, I know, because I’ve made them.
In light of that, I’d like to share two of the worst mistakes I’ve made brewing kombucha – and hopefully keep you from making them too!
Kombucha brews best between 70 and 80 degrees Fahrenheit. That might seem like no problem in a home where a comfortable temperature is maintained. But you need to be careful where you leave the container during the brewing process.
My mistake: Leaving my kombucha to brew in the basement, where it was much colder than I thought.
Guess what happens when your scoby gets too cold?
It grows mold and you have to toss the whole kit-and-caboodle. If you want to learn more and see some gross pictures, Kombucha Kamp has a whole page about moldy scobys. In general, warmer temperatures will speed up the brewing process, but if it gets too warm, the scoby may be damaged.
During the winter months, some people use a heating pad to maintain a consistent temperature. Also, never leave your brewing vessel in direct sunlight, as it may interfere with the brewing process.
The fix: I now set my glass brewing container on a top shelf in a cupboard or closet – where I know the temperature is consistent and there is no direct sun shining on it.
Fruit flies LOVE kombucha because of its sweet, vinegary flavor. In fact, kombucha makes a great fruit fly trap if you have a fruit fly problem in your home.
My mistake: Using cheesecloth as a cover for my kombucha.
Turns out that the holes in cheesecloth are small enough for fruit flies to enter. Unfortunately, cheesecloth is mentioned in many kombucha tutorials and even my very popular kombucha post includes a photo with a cheesecloth cover.
I learned this lesson the hard way this past summer, when I discovered a major fruit fly infestation in my scoby. It wasn’t just a few fruit flies, it was TONS, because they were breeding in there.
Grossest thing ever – you don’t even need to see pictures. Needless to say, the entire mess had to be tossed and I had to buy a new scoby and start over.
The fix: I now use a breathable, cotton dishtowel or napkin to cover my kombucha container. You can also buy covers from Kombucha Kamp if you prefer.
Do a secondary fermentation in bottles to increase carbonation – learn how to do a secondary fermentation and get my 5 Favorite Fruit Flavored Kombucha Recipes here!
Do you make homemade kombucha? What brewing method works best for you?
5 of the Best Fruit Flavored Kombucha Recipes + How to Get That Fizz!
I have never heard of kombucha before. I learn new things every day.
If I am making both kombucha and kefir, do I need to keep them separate? Will they cross contaminate each other?
Good question Kristie! I’ve heard that they do interfere with each other so we always keep them separate if we have both going at the same time.
When you do the secondary fermentation to increase carbonation, are the bottles still left out at room temperature? Do you then refrigerate the bottles when you’re happy with the level of carbonation and ready to drink? Thanks.
Hi Lorna – Yes, I do the secondary fermentation at room temperature for at least 2-3 days. Just remember to “burp” them once a day to keep the gas from building up too much. You don’t want an explosion!
I totally use cheesecloth myself when it comes to making Kombucha.. how scary! Is there different micron levels for cheesecloth? Maybe there is a hole size that doesn’t allow the flies to get in! I definitely don’t want to experience this when I’m making kombucha the next time! Thank you for sharing this!
Hi Billy – Not sure about different types of cheesecloth – once I had the fruit fly infestation, I never went back to cheesecloth again!
I use coffee filter. Works perfect.
I also use coffee filters. Never had a problem in the two years I’ve been making it.
I’ve been making both kombucha and kefir for a while now. I know most recipes say take the tea bags out after about 15 mins but on the whole I use loose oolong tea or green tea and just let the whole brew get to room temperature before straining it into my bit Kombucha 12 pint jar. I leave it for a week or so and then strain off about 6 pints. That goes into bottles for storage and is often flavoured. the last lot had 1 x plain grated ginger, 1 x grated ginger with allspice and 1 x grated ginger with lemon zest. The rest stays until it goes really vinegary and then I take that off and use for salads, pickling and whatever else one uses vinegar for. I leave about a couple of cups in the pot and then just add another 12 pints of tea/sugar brew and the whole process starts again. When there are so many scobies in the bottom of the jar that the exit tap is beginning to get blocked, I take out all the bottom ones along with the strings of yeast which are usually there as well. My aim is to touch the scobies and the brew as little as possible so there is less chance of contamination. It seems to work. Only snag is my other half dislikes the taste so I end up with far too much on the shelf but it lasts for several months and so far the bottles – flip top beer ones – have not burst.
Sounds like you have quite the production going! I’ve never tried lemon zest in my kombucha – I’ll be trying that soon!
I usually leave it out on the counter for a few days to help in the carbonation process, but then put it in the refrigerator because I don’t want the bottles to explode!
I tend to put in a “cool” place. I have an unheated storage area/barn where I keep it. I use swing top strong bottles and, so far, have had no explosions and sometimes they are there for four months or more. I do tend to go to 2nd fermentation when the sugar has gone so only the added ginger, handful of blackcurrants or whatever are giving sugar to work the ferment. But to answer your question I do not see the need to actually put them in a refrigerator.
Once the scoby is out, I would guess they would remain the same – although kombucha does vary batch by batch so it’s impossible to predict!
Couple questions 1. Can I use coconut sugar? 2. Can I use organic green tea bags flavored with mango?
Hi Machel – Very good questions! I really don’t know about the coconut sugar – I would recommend checking with an established kombucha company like Kombucha Kamp – I bet they’ve had that question before. As for the green tea bags, I’ve heard that they don’t work very well and that you really should stick to black tea for kombucha. Let me know if you hear otherwise!
I use green tea bags exclusively, and I love the light, fruity flavor. My kombucha seems to be less tart than that made with black tea. I use one gallon of purified water, one cup of organic sugar, and five green tea bags. I have used both organic and non-organic tea with satisfactory results. There is a huge variety in recipes when it comes to length of time for boiling the water (if at all), number of tea bags, the length of the steep, etc. If you want to experiment, keep a baby SCOBY stored in a cup of kombucha just in case your experiement fails.
Someone asked about green tea flavored with mango. Don’t use flavored green tea; it gets moldy and kills your SCOBY. I read that you shouldn’t use it, but I tried it anyway. I then had to grow my own SCOBY, (thanks Pinterest) which worked just fine, although it took longer and the SCOBY was lumpy and uneven.
Thanks for sharing your tips and mistakes Marty. Kombucha making is definitely a combination of art + science!
Hi there I found my cloth left some particulates in my brew… (pre Scoby formation) I have since changed the cover to a coffee filter… should I be worried ???
I wouldn’t worry about it too much – you can always strain it out if you prefer.
I use coffee filters. They actually work really well. Not to mention, they cam be changed easily if they get splashed. I feel they keep the brew much cleaner. Yes, they are breathable. ..I cover my kambucha jug with a coffee filte then a pretty cloth napkin. I always use a rubber band,then a nice satin ribbon to keep it pretty. I have a very small kitchen without cupboards, so I really want to make sure it stays clean.
I like the coffee filter idea!
Just now learning so sorry if this is a stupid question but what does ‘second fermentation’ mean or how do you do it? Also, what causes an ‘explosion’ and how do you avoid it? Thanks.
Hi Linda – A second fermentation happens when you put the kombucha into smaller bottles and add either dried fruit or some fruit juice (without the scoby). The sugars from the fruit allow the kombucha to continue to ferment and I find it helps to make the kombucha more fizzy. An explosion would only happen if the pressure in the bottle became too great. You can “burp” your kombucha bottles every few days to release the pressure. Hope that helps!
Hi there, i’m very new to this i haven’t started yet, but i have a scoby in the fridge waiting for me. Due to health reasons i am unable to consume caffeine, other than herbal tea which i’m told you shouldn’t use, is there any other tea i could use that has no caffeine in it?
Good question Lily! I have heard that only regular black tea works well – however I have never tried decafinated tea in a batch so I am not sure.
We use decaf black tea and it works fine.
I am wondering if a Coffee filter would work over the jars? I am just starting out and they are such nice lint free filters, that it seems like they’d be perfect.
I sure would think so Helen. Let me know how it works for you!
The coffee filters have been working great… and as someone else said- when they get splashed or I make a new batch I change it.
I do have a question. 15 cups of water to 4 tea bags? Are these individual tea bags or family size?
Those are individual tea bags. Lately I’ve been bumping it up to 6 tea bags per batch. It depends on how strong you like it!
I’ve made my first batch of Kombucha. It took so long for the new SCOBY to form (and it’s still really thin) that the whole thing took me longer than expected. I now have a gallon of it but I’m leaving at the end of the week for a weeks vacation. Is it okay to leave the SCOBYs in some of the tea without using it right away? In the fridge or out? How long will the refrigerated tea last?
Technically you are not supposed to refrigerate your scoby because it could get too cold and produce mold. That said, I have refrigerated mine when I’ve been out of town and it has been just fine. I can’t tell you how long the refrigerated tea will last – sometimes you just have to experiment and see what works for you and your particular environment.
Wendy, I would take off half the tea and bottle it in strong bottles and keep these reasonably cool and they will be fine for a week or two. When you return, if they are still too sweet you can reintroduce them to the scoby. You can then leave your thin scoby sitting in the remaining tea or even give it more tea and sugar where it will make you some more kombucha for when you come back. This you can keep at room temperature – not too warm unless you want vinegar when you return – or too cold or the scoby might get unhappy and grow mould. you might find you have a much thicker scoby or even a new one on top of the old one. I have kept scobies in kombucha for many weeks with no problems.
I would like to give it a try to your recipe but if I live in a area were the regular temperature is 33c• should I leave it for such a long time? (3 weeks); what I remember on the first batch I made is the I try it at the 6th day and it was good, the 7th day it was a little strong for my taste, so I decide to take it to the fridge and stopped the fermentation, but I don’t know if your recipe works best with those times because of the quantity of tea bags you use.
Another thing, I try to keep to the minimum sugar consumption, how can I make this work without that much sugar? Can I mix some other natural sweetener like stevia leaves?
Thanks in advance for any hint you can give me!
Hi Alejandra – In terms of time and temperature you will have to experiment with what works best in your environment and for your particular taste. As far as the sugar goes, the scoby needs that sugar in order to ferment the tea. The resulting kombucha does not have much sugar content although I can not tell you exactly how much. Stevia or other sweeteners will not work to ferment the tea. Hope that helps!
What do you mean by add “1 cup of finished kombucha”? I feel a little dumb but we don’t have finished kombucha yet as we are in the process?
Hey Beth – Since this is your first time making kombucha you will need to use a cup of store-bought kombucha as your starter!
No reason to worry – it’s another scoby forming on the top. This is quite common in fact it happens almost every time! You can keep extra scobys in some kombucha as a backup, or give one to a friend, or just compost it. Enjoy your kombucha!
My bottles with fruit look like they’re making a SCOBY. They have been out on the counter for 2 weeks. Is this bad? Do I need to filter them and refrigerate, or dump?
That’s totally natural Lisa! You’ll probably want to filter the little scoby out to avoid drinking it (it’s not bad for you – just slimy!).
Hi Bonnie – good question! I have never made my own scoby but I’m sure you can find out how somewhere on the Internet!
Which diseases can Kombucha heal?
Hi Emily – I wouldn’t say that kombucha heals any diseases – but it is very good for gut health and boosting your immune system.
Thanks for all the great information. Complete beginner here. I’m trying to take it all in before I dive in. So 2 questions. 1. If I don’t have my own Kombucha already what would I use as the”1 cup finished Kombucha”?
2. How do you do the secondary fermentation in the bottles?
I’m sorry if these are obvious, dumb questions.
No dumb questions here! 1. Use kombucha that you purchase at the store the first time around. 2. I add dried fruit and a squirt of honey to individual bottles, then use a funnel to pour kombucha from the gallon jug into the small bottles. I leave the out at room temperature so they will get fizzy!
Hi Micaela, a question about my Kombucha….I had been right on top of each batch until this past week when I was only able to bottle 1/2 of my batch. Today I realize the rest is vinegar tasting…. I have poured off almost all of that and kept the 1 1/2-2 cups starter but am unsure whether this will taint every batch following. Can you advise me?
I’ve had similar things happen but I find that a new batch ends up being fine! My batches seem to vary some over time and conditions like temperature and length of time – but it always seems to be OK in the end!
I went ahead and completed my batch…. fingers crossed. thanks for your response.
Pity to ‘pour off’ the vinegar tasting Kombucha as it becomes just that; vinegar. Very useful not only in salads but brilliant in a spray bottle to squirt at any insect bite. It stops the itch and is also good for pickles or indeed any place one might use cider vinegar or indeed any other vinegar. When I’ve been away and a whole gallon has gone too vinegary I have used it for cleaning windows, rinsing my hair, soaking my feet and all the other things vinegar is useful for. And certainly your next brew will be fine.
How does the secondary fermentation work? All tutorials stop at the 1st! Not explaining how long to ferment and then how to stop it!
I presume it needs putting in the fridge?
Thank you. Will be buying items down the line.
I’ve been brewing for a few years now and have made almost every mistake possible haha it took a bit to get my grove but now I have a system! I don’t use a cloth cover though I use a coffee filter- I may have to try your idea!
Glad to hear you pushed through the mistakes and found a kombucha brewing system that works for you!