The Ultimate Guide to Figuring Out if Your Kombucha SCOBY Has Mold (or NOT)

Probably the most popular question I’m getting in the comments, to my email box, and as as search time people are finding this site with, is ‘does my SCOBY have mold?’ or ‘Is my SCOBY bad?’

IF you’ve followed the brewing instructions correctly — you’ve made a sweet tea mix and adding about half a cup to two cups (roughly 10 percent of your mixture) with Kombucha Starter (kombucha from your previous mix) OR, if you don’t have Kombucha Starter, white vinegar, there is very little risk that MOLD will grow and little risk your Kombucha brew will turn bad.

Let me repeat, as long as you have some kind of sweet tea (caffeinated tea with some sugar with the whole mixture room temperature), Kombucha Starter, and a LIVING SCOBY), it’s very unlikely you’ll end up with a bad batch or mold of any sort.

Sometimes, your SCOBY can take on a discolored look. Instead of a white or whitish SCOBY, you can get a brown looking one or even a yellowish one. This is simply the SCOBY taking on the color of the tea. I find depending on the TYPE of tea used and HOW LONG you leave the SCOBY in the kombucha brew for, the color will change. The darker color the tea, the darker your SCOBY will be when you take it out, especially if you leave it in for more than a couple weeks.

For example:

Liptons tea tends to give my SCOBY a very brown dark look.

Green Tea tends to give my SCOBY a whiter look

Black/Red Tea tends to give my SCOBY a yellowish tinge.

Because people are naturally concerned about how their SCOBY is doing, I’ve decided to walk you through what some of the different SCOBYs look like and what MOLD on a SCOBY looks like.

How to Tell If a SCOBY has Mold

When your Kombucha has mold, it’s obvious and it’s not obvious. There are some situations where your Kombucha can look like it has mold growing on it, but doesn’t have it. So I’ve cooked up this article as a visual and written guide to figuring out if your scoby has mold.

I’ve addressed the SCOBY mold questions on some other articles, so do read those as well.

1) A Moldy Kombucha SCOBY Almost Always…

Is colored Green,Black, or Blue and covered with fuzz

Grows in circular patters with the edges often having a vein-ey look at the edges (see image)

Is Located on the TOP of the SCOBY in contact with the air. Mold won’t be under the mixture or inside a SCOBY layer.

If you’ve ever seen moldy bread, milk, fruit, or any other substance, mold on a SCOBY looks almost the same.

Look at the images below. THIS is what MOLD looks like on your Kombucha:

Note how the mold is green and fuzzy for some of these? In one case, it’s white but the edges have a vein-ey look and there’s fuzz on it. In every example, mold is growing on the surface.

2) Moldy SSCOBYs Smell Strange

So…make sure you Smell Check your Kombucha.

You can also tell a lot about the health of your Kombucha (and the SCOBY) by the smell of the brew. The mixture should smell faintly sweet and slightly vinegary (the older it is, the more sour and vinegary it smells).

If the brew smells off, stinks, smells moldy, or foul, absolutely do not drink it. Throw the brew and the SCOBY away and start over with a fresh SCOBY from your SCOBY Hotel.

3) Mold is only likely to form in the following situations:

Your Kombucha is sitting near garbage, moldy food, or plants — mold spores can migrate over into your Kombucha

You did not use Kombucha Starter

There is extreme humidity

It’s very cold

Kombucha brew exposed to cigarette smoke

How to Prevent Mold

Here’s how to prevent mold:

Use Kombucha Starter (from previous batch or your SCOBY hotel)

Sprinkle some white vinegar on top of your brew (1 or 2 table spoons is enough)

Keep your Kombucha in a warmer area — if the temperature is cold, use a heading pad or keep your buch somewhere warm

Do not place Kombucha anywhere near your garbage

Keep kombucha away from plants

Do not leave old food near Kombucha (fruits, bread, etc)

Keep cigarettes away from brew

Make sure you also read my How to Prevent Mold article for more info

What to Do If You Find Mold?

Throw it all away — both Kombucha AND SCOBY. Don’t try and salvage the scoby either — toss it all.

I’ve written a whole article on what to do if you find mold on your SCOBY.

The Different SCOBY Looks

You really should not even CHECK your Kombucha for 5 to 7 days. If you do, you may freak out and think the newly-forming SCOBY is mold. If you do check your kombucha within a couple days of first creating the brew, you may notice the following cases below. Relax, it’s not mold.

Little White Circles On TOP Surface

When a brand new SCOBY is forming at the TOP of your mix, and the old SCOBY is at the bottom of your bottle, the SCOBY formation at the top can look to people NEW to brewing Kombucha just like it’s mold.

But it’s NOT mold on top of your brew — it’s simply the formation of miniature SCOBYs on the top surface that will eventually link together forming a single SCOBY.

The above case happens WHEN the SCOBY sinks to the bottom of your brew mixture leaving the top surface to form a brand new SCOBY that’s not attached to your main SCOBY. In time, the main SCOBY at the bottom may float to the top and merge with the new forming SCOBY, which will end up as the BABY SCOBY eventually. Or in some cases, the mother/main SCOBY may stay at the bottom and you’ll end up with the BABY scoby at the top, not attached to the MOTHER.

Here are pictures from my OWN kombucha brew. These little white spots are simply mini SCOBY’s forming on the top surface. They are simply white and soft, NOT FUZZY (mold is fuzzy). These little white circles will eventually merge into a single one.

Big White Circles on the Top Surface

Translucent Slime on the Top Surface

This is simply when the little SCOBYs have all emerged together. You get slimy coating on the very top layer of your brew. This is natural and normal. If you wait a few more days, this thin slime will turn into the actual SCOBY shape you are expecting, though it will be thin.

Dangling brown/white bites from UNDERNEATH your SCOBY

Another worry people often have is brown, yellow, or white strands hanging from beneath the SCOBY down into the brew. They frankly look pretty scary, like some sort of spinal cord floating in liquid, attached the head of an alien.

Relax, these strands are simply the Yeast that’s coagulating. They are part of the Kombucha. In fact when you drink Kombucha, you will be drinking these yeasty bits anyways. Even if you don’t see them, they will still be there, very small. If these floating pieces bother you, simply strain your kombucha after it’s finished to remove them.

Brown, Black, or Yellow streaks, lines, or splotches on the Kombucha SCOBY or parts of it.

There is nothing wrong with black, or brown lines, streaks, splotches or goo on your SCOBY.

Very often you’ll often get dark slimy streaks on your SCOBY. This is simply part of the culture — likely the yeast (remember SCOBYs are a combination of YEAST and Bacteria) which often takes on a different color. It could be parts of the OLD SCOBY too, if you’ve been reusing both the mother and the baby, rather than removing the baby and tossing the mother.

When you take the SCOBY out after the batch is done, simply with your fingers peel off the slimy discoloration and throw it away. Often the new BABY on the top will be a white color with less streaks, you can just peel this off and use this and toss away the Mother. Or you can re use the whole thing without issue.

Wet, slimy black stuff on your SCOBY is not mold and it’s not a sign that your SCOBY is decaying. I get this all the time on my SCOBYs.

I recently had Sarah, one of the readers on this site, send me the following email:

Hi there, I found your email on your website. Would you mind possibly telling my whether my scoby is ok or not please? I’m attaching photos. I was away for about three months and came back to find about double the amount of scoby in the jar! The top one and the baby look ok to me but I’m concerned about the brown mess that’s developed below the top one. I’d massively appreciate a helping hand as to whether it’s ok or not! Thanks so much Sarah

And here are the pictures Sarah sent me:

The above pictures are perfectly normal, healthy SCOBYs. If you keep on reusing the same scoby, eventually the older parts star to discolor (presumably die) which doesn’t effect anything but just looks kind of nasty. you can simply peel them off with your fingers. The discoloration can also just be the tea color staining the surface of the SCOBY — which happens the longer you leave your SCOBY in a brew or if your tea is particularly dark.

Or, always peel away the mother, toss it, and keep the baby. The baby will usually always be a bit whiter and fresher looking.

Yellow, Brown, White, Orange Colored SCOBYs

Healthy SCOBYs come in a variety of colors. Don’t freak out if your SCOBY is NOT white.

WHITE scobys are the typical color BUT a number of things can affect the color as well:

how old your SCOBY is

is it the baby or the mother

has it been re-used over and over

Is the SCOBY from your SCOBY hotel (and been sitting there for a long while?)

Has the SCOBY been sitting at the bottom of your brew in the bottle or has it been at the top of your brew surface

Look at some of the color variations (these are all healthy SCOBYs):

I generally find IF the SCOBY is at the top of your container, it tends to be white. If the SCOBY sits submerged in your brew and not at the top (it usually will eventually move to the top, but not always), the SCOBY tends to be more brown, or orange, or caramel in color due to the tea color permeating the surface of the SCOBY and ‘coloring it’. The tea color too makes a big difference. If you have a very dark colored tea, your SCOBY will take on a darker, brownish orange hue. If your tea is a lighter color, your SCOBY may be whiter. SCOBYs taken out of a SCOBY hotel are usually darker in color too, as they are all usually submerged in the liquid (not enough room to sit at the top touching the air).

The Final Word

I’ve given you some real detail her that should help you figure out if your SCOBY is good or not.

Let me repeat myself by saying it’s pretty damn hard to screw up your Kombucha. Provided you don’t do something dumb like:

…forget to put SUGAR into your tea

…throw your SCOBYs in to a boiling hot sweat tea mix

…not using Kombucha Starter (or vinegar)

…placing your brewing kombucha bottle right beside your lidless trash can full of moldy garbage

…not putting a cover on your brew and leaving it outside in the garden

…if you are concerned, you can also put a couple tablespoons of White Distilled vinegar on the top of your Kombucha liquid to help fight against mold infestations. You can use Apple Cider Vinegar, but be aware you are then mixing in a live bacterial culture from the APV into your Kombucha. This mixing of another colony of bacteria can affect the flavor of your Kombucha, permanently.

Note that you should be using high quality ingredients as well, for best SCOBY health. Better ingredients mean your SCOBY is given the best materials (free from chemicals or toxins) and will grow better, meaning it can fight off MOLD infestations or other kombucha problems.

What are the GOOD ingredients? Here’s my recommendations for what you should be using to brew your Kombucha with. You certainly don’t need these exact brands, but I’ve tested these and they do very well with Kombucha –and I love the flavor. You can get by on inferior ingredients, but I firmly believe you should brew with the best for the best quality.

Organic Whole Cane Sugar



You can use any sugar — white refined, organic cane, even sugar beet sugar. I recommend though you look at ORGANIC sugar. And while organic white refined cane sugar will do just fine, my personal favorite is the Rapunzel Organic Whole Can Sugar. It’s the most minimally processed sugar you can buy, produced by old school hand methods with very little processing done. However, it’s more expensive than regular sugar, but if you want the highest quality ingredients, it’s worth it AND your SCOBY will love it. For the penny pinchers though, I just recommend you buy some bulk organic white refined sugar and you’ll be fine. And yes, buy in BULK because you will be consistently needing sugar for your Kombucha brewing each week or two, so you’ll save a lot of money just ordering it in bulk 10 or 25 lbs rather than 1 lbs or 1/2 lbs that you normally would.

Quality Organic Tea

For example, Davidson’s Organic Black Tea works very well for Kombucha brewing. SCOBYs love it! For green tea, I also recommend Davidson’s Organic Jasmine Green Tea as well. And I recommend going with loose leave tea over teabags, though you can still brew just fine with Tea Bags. Loose leaf tea is better quality and gives a more complex flavor I find though.

Clean Glass Jars

You likely have plenty of glass jars at home. But if you want a specific jar that’s BIG enough for a 2 gallon brew (roughly 2 weeks of Kombucha for the average person) and one that’s easy to remove the finished brew via a spigot, then look at the Anchor Hocking Dispenser jar with spigot (just switch to a stainless steel spigot though).

CLEAN Spoons / Strainers

I recommend the three set OXO strainer. IT’s suitable for your kombucha, it’s cheap, and it has three sizes included. This is just MY recommendation — any strainer you have will likely work. I do recommend you either use STAINLESS steel strainers or plastic ones so there is no interaction with between the materials and the kombucha.

Stainless Steel Spoons

You can use plastic spoons (food grade) just fine. But I prefer stainless steel. This is the set I use. You can use stainless steel, glass, wood, or food grade plastic.

YOU should have no problems with mold growing or getting a contaminated batch. Mold is RARE. I’ve only had it ONCE in in the years of Kombucha brewing, my mom who’s been doing it for years has never had it, and various family members who brew it have never had it.

If you have mold once or multiple times, you are a special case. Unless you are TRYING to grow mold on your culture specifically, you shouldn’t have an issue.

That means if your Kombucha SCOBY looks strange and funky, there’s probably a 95 percent chance that’s the way it’s SUPPOSE TO LOOK. Because SCOBYs are disgusting look, strange looking, and funky looking anyways.

My final tip is smell your brew. If it smells rotten, stinks, or is moldy, or smells disgusting, then don’t drink it and start again.

Simple.

I hope this helps you guys and…Happy Brewing!

Ben

(Visited 132,745 times, 14 visits today)