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Kombucha Troubleshooting

Kombucha Troubleshooting: What to do when things go wrong | Wellnesting

I have a confession to make: My first batch of kombucha turned out less than stellar.

And that’s the understatement of the century.

Roughly two weeks into brewing I started running into trouble. At first it was just a few white specks on my SCOBY, but then it started taking on a blue-ish tint and growing like gangbusters. And in a matter of days my SCOBY was completely covered in a blue-green fuzz like something straight out of a horror movie. Although I’m not usually the squeamish type, I’ll be the first to admit it was by far one of the grossest things I’ve ever grown.

And I’ve grown a lot of gross things.

It was so bad that (and here comes confession #2…) I refused to toss it. Instead I just pretended it wasn’t happening and let it continue fermenting for, oh, another couple weeks. I even took a picture to show you guys but I can’t even bring myself to look at it again. Consider yourselves spared.

So when my husband met Brett Nobile, the owner of Ninja Kombucha, a few weeks ago, I knew it was fate. Ninja Kombucha is a local kombucha company here in Richmond that makes some of the best kombucha we’ve ever had (and I’m not being paid to write that – it’s just that good), and Brett was nice enough to let me pick his brain and ask all those embarrassing newbie questions that everyone thinks but hates to ask out loud.

So if you’re running into brewing problems of your own or just want to make sure you’re doing it right the first time, follow along to read Brett's advice on how to troubleshoot your brew.

Kombucha FAQs

My SCOBY doesn’t seem to be doing anything, how do I know if my culture is fermenting properly?

There are several things you can look for and measure to check in on the ferment. pH is number one. It should start higher and drop over time. You can use a pH meter to get an exact reading or just taste. As the pH drops it will taste more acidic and vinegary.

You also want to look for growth of the SCOBY. It should get thicker over time and develop brown yeasty strands that hang down from the bottom. It may not grow an entire new disk every batch but there should be some growth on it. Generally the new growth is the purest white, translucent part and the older SCOBY will be a little more dark and tan from being in the tea. There should be some yeast sediment forming at the bottom of the jar.

Also, look for bubbles. Bubbles are good, that means it’s fermenting. 

It’s been a couple weeks and my kombucha still tastes way too sweet, is this a problem?

It just depends on your taste preference. Some people really want that sour profile and some people like it a little sweeter. How quickly the kombucha turns from sweet tea to vinegar is dependent mostly on temperature and the amount of starter you use.

You want to keep the kombucha warm (70F-80F). The yeast and bacteria are more active in a warm environment and they will be able to ferment faster. There are a lot of ways to do this: put it by a hot water pipe, seedling heater mats, and heating elements made specifically for fermenting are all good options. Also if you just put it in the highest place in the room it typically tends to be a few degrees warmer up there. It is amazing how active kombucha is when it’s warm.

Most recipes call for about 2 cups of starter fluid per gallon. The starter fluid acidifies the batch and creates an environment where the bacteria and yeast are going to thrive and out-compete other organisms. You can use more starter fluid if you want, it’s not going to hurt anything. It gives the yeast and bacteria even more of an advantage and will make the whole fermentation process a little shorter. If you’re having trouble getting the taste you want in a reasonable amount of time double the starter fluid to 4 cups per gallons.

My SCOBY isn’t big enough to create a seal at the top of my jar, should I be concerned about mold or bad bacteria getting into my brew?

It’s not a problem if the SCOBY doesn’t cover the whole surface of the tea at first. You should be protecting the brew by acidifying the batch either with older fully femented kombucha or pasteurized/distilled vinegar. The scoby should grow to cover the surface of the jar in a couple of weeks.

This is my first batch of kombucha and there’s clearly mold growing on my SCOBY, what might I have done wrong?

If you got mold on your first batch don’t worry just throw it out, clean everything and start again. I recommend cleaning with OneStep or StarSan which are both home brewing sanitizers but you can also use warm soapy water (just make sure you rinse well) or distilled vinegar. For the next batch increase the starter and make sure your kombucha stays warm.

It could have been from the type of tea you used. You don’t want to use Earl Grey because the bergamot oil in it weakens the SCOBY. Stick with straight black or green tea. It should be pure Camellia sinensis with no other ingredients. Once you have a strong SCOBY and some backups you can start to experiment more with other tea blends and tisanes if you want.

There may be environmental factors. If you’re fermenting right by the trash can or compost bin you will probably want to change locations. It also doesn’t hurt to dunk your scoby every now and then or just take a straw and drizzle some kombucha over it.  You just want to let that acidic solution cover the top of the SCOBY where it’s exposed to the air.

My SCOBY is growing but it’s very thin and won’t stay intact. Is this normal?

It depends what you started with. If you are growing your own SCOBY from scratch it is normal for it to start out thin and get thicker over time. If you started with a SCOBY from a commercial source it should be at least a quarter of an inch thick. Kombucha Kamp is a great resource for home brewers. Their cultures are super strong and active. I would discourage starting with a dehydrated culture.

I’m having a problem with fruit flies being attracted to my brew, what’s the best way to keep them away from my SCOBY?

Cover the jar with a breathable fabric with no holes or openings for the flies to get through and secure with a rubber band. You can cut up an old t-shirt, sheet, or pillow case and that will work well. A lot of people use coffee filters as well.

Are there any other tips you might have for beginners? Things you wish you had known when you first started brewing?

Never use unpasteurized or raw apple cider vinegar for starter fluid or to clean your vessels. There is a species of nematode, Turbatrix aceti, that feeds off the mother of vinegar that can be present in these products. They are harmless and have been a part of vinegar production for hundreds of years but you do not want to find these things in your brew. It’s just gross.

I think taking care of a SCOBY is pretty analogous to taking care of a plant. You just need to nurture them for them to grow. The more attentive and caring you are with how you nurture them the better your results will be. Plants need water and light. SCOBYs need air, sweet tea, and warmth.

Just don’t give up! Kombucha is such an awesome home ferment and it can make you feel really good. If you’re having problems ask around. Usually people who brew kombucha are willing to help. It’s a great community to be a part of and exchange ideas in. If you’re having problems keeping up with your batches check out the continuos brew method. It is super low maintenance and really forgiving.

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And a big thanks to Brett for doing this!

If you're in the Richmond area and you'd like to try Ninja Kombucha for yourself, stop by Growler's to Go to get a pour or consider getting a monthly Ninja Kombucha membership.