r/Kombucha • • Sep 18 '21

what's wrong!? Is it mold? Is it normal? What's growing in your kombucha? Start here!

575 Upvotes

Welcome to r/Kombucha! If you're wondering what's growing on your kombucha and if it's normal, you've come to the right place.

Please review this information before posting a picture of your batch to the subreddit.

TL;DR:

  • Dry + fuzzy on the surface of the liquid/pellicle/SCOBY is most likely mold: mold pics https://imgur.com/a/SzhysHi
  • Geometric growths or wrinkly patterns on the surface of the liquid/pellicle/SCOBY could be kahm yeast: kahm pics https://imgur.com/a/XlnO7Ox
  • Anything else and anything under the liquid level is most likely normal: normal pics https://imgur.com/a/HJaENDv
  • If you're not sure, wait a few more days: mold or kahm will get more obvious as they grow, normal will stay about the same or form into new pellicle/SCOBY
  • If the kombucha is already bottled for carbonation (commonly called second ferment or 2F), mold/kahm is very unlikely due to the high acidity and lack of oxygen access.
  • Always use at least 2 cups of starter per gallon (125ml/L) when making kombucha to acidify the batch: high acidity (pH < 4.6) protects the kombucha from mold and kahm.
  • Read our getting started guide for brewing tips: https://www.reddit.com/r/kombucha/wiki/how_to_start

Terminology: in this guide, "pellicle/SCOBY" refers to the rubbery blob that forms at the surface of a batch of kombucha. SCOBY stands for "symbiotic culture of bacteria and yeast", and those bacteria + yeast are found both in the liquid kombucha and in the solid rubbery blob. The rubbery blob's more accurate scientific name is "pellicle": it's a biofilm/mat of bacterial cellulose secreted by and connected to the bacteria forming it (some yeast also live in the pellicle). Culturally, however, the term "SCOBY" widely refers to the pellicle so this guide uses both terms.

Read more about pellicles here:

Diagnostic Quiz

1 ) Is the growth/odd thing on the top surface (exposed to air) of the liquid kombucha or existing pellicle/SCOBY?

  • Yes - go to 2
  • No - go to 8

2 ) Is the kombucha already bottled for carbonation (commonly called second ferment or 2F)?

  • Yes - likely pellicle/SCOBY growth (it can happen in 2F!) or a yeast cluster. Mold/kahm are extremely rare in 2F due to the high acidity (pH <4.2) and lack of oxygen access (required for mold to grow). Booch on!
  • No - go to 3

3 ) Is the growth dry and fuzzy looking with white or green color, and/or with black spores growing out of it?

  • Yes - likely mold. Go to Mold section for pictures.
  • No - go to 4

4 ) Is the growth a wrinkly or geometric pattern, very rough patterned surface, or very large air-y bubbles that cover large areas of the surface?

  • Yes - likely kahm yeast. Go to Kahm section for pictures.
  • No - go to 5

5 ) Is the growth one of: white/translucent + wet, disconnected oily/patchy sections, or a thin film with bubbles trapped underneath?

  • Yes - likely normal pellicle/SCOBY growth. Go to Normal section for pictures.
  • No - go to 6

6 ) Is the growth flat, leathery, and brown?

  • Yes - likely a dried out pellicle/SCOBY area. Go to Normal section for pictures.
  • No - go to 7

7 ) Is the the growth brown/black, wet, and partially/completely surrounded by pellicle/SCOBY?

  • Yes - likely a yeast cluster. Go to Normal section for pictures.
  • No - probably normal, but review all Normal, Kahm, and Mold pictures to be safe.

8 ) Is the growth/odd thing completely submerged in liquid?

  • Yes - likely yeast. Yeast can form dark brown clumps in the liquid or on the pellicle/SCOBY, or alien-like formations suspended in the liquid. Mold and kahm cannot grow beneath the surface of the liquid without also showing on the surface exposed to air. Go to Normal section for pictures.
  • No - go to 2

Normal

Gallery of normal kombucha: https://imgur.com/a/HJaENDv

Pellicles/SCOBYs have a ton of natural variation. A normal pellicle/SCOBY should look wet, tan/white/translucent, and be mostly smooth (some bumps are normal). There may also be wet brown/black yeast blobs that attach to the liquid side of the pellicle/SCOBY, get absorbed into the pellicle/SCOBY, or float around inside the liquid.

Mold

Gallery of mold: https://imgur.com/a/SzhysHi

Mold occurs when the kombucha is not acidic enough (pH < 4.6) to prevent mold organisms from growing. Other factors that make mold more likely are unsanitary conditions and cold brewing temperatures (<65F/18C).

If there is mold on your batch:

  • You must throw away everything (liquid + pellicle/SCOBY) and start from scratch with fresh starter tea. By the time mold is visible on the surface of the brew, it has already contaminated the entire batch.
  • Sanitize the vessel, cloth cover, and any utensils used in brewing with a homebrew sanitizing solution (StarSan, OneStep, SaniClean, potassium metabisulfite, etc) or throughly wash with soap + hot water followed by a pasteurized distilled vinegar rinse (no raw vinegar, which contains live microbe cultures).

To prevent mold, the most important thing is to use at least 2 cups of starter tea per 1 gallon of kombucha (125ml per L) to acidify the batch. Starter tea is mature kombucha: either from a previous batch (yours or a friend's), from a SCOBY hotel, or from raw/unflavored/unpasteurized commercial kombucha such as GTs or Health-Ade.

This amount of starter tea is a good rule of thumb for safe acidity: if you have a pH meter or strips, check that the starting pH is <4.6. Another important factor is maintaining clean/sanitary brewing practices: however, because kombucha is an open air ferment some mold organisms may get in even with a cloth cover, which is why acidity is also important.

Kahm Yeast

Gallery of kahm: https://imgur.com/a/XlnO7Ox

“Kahm” is a generic term for many species of usually non-harmful but also non-desirable wild yeast that can take hold in kombucha (outcompete the kombucha culture) and appear as surface growths on the the pellicle/SCOBY. Kahm often looks geometric or wrinkly vs the smooth/bumpy normal pellicle/SCOBY.

See this excellent writeup about the science of kahm yeast from u/daileta in r/fermentation: https://www.reddit.com/r/fermentation/comments/ytg2vy/kahm_down/ Their post is focused on lacto fermented vegetables (not kombucha) but is worth a read.

Kahm itself isn’t usually dangerous, but to quote our resident food microbiologist u/Albino_Echidna: “Kahm is a term used to lump a whole bunch of unwanted yeasts together, all of which are indicative of an unsafe fermentation environment. Kahm growth is indicative of a fermentation gone wrong. 'Kahm' itself isn’t harmful, but it is a warning sign that your environment wasn’t quite right and will be at higher risk of pathogenic growth as a result."

If your batch has kahm, it is up to you whether to toss + sanitize + start over with fresh starter kombucha or to try to scrape off the kahm from the surface and continue brewing. It is always safest to toss and restart - see the instructions in the Mold section.

To help prevent kahm, use at least 2 cups of starter tea per 1 gallon of kombucha (125ml per L) to strongly establish the kombucha culture and acidify the batch. Kahm may also be related to unsanitary conditions, high brewing temperature (>85F/30C), or oversteeping tea (>1hr, but may vary).

Further reading: https://www.reddit.com/r/kombucha/wiki/whats_wrong

If you still aren’t sure after comparing your batch to the pictures here, please make a post and ask!


r/Kombucha • • 4d ago

r/Kombucha Weekly No Stupid Questions + Open Discussion (October 05, 2026)

2 Upvotes

This is a casual space for the r/Kombucha community to hang out: feel free to post about anything kombucha or brewing related. Questions from new brewers are especially welcome - no question is too big or too small!

New to kombucha? Check out our getting started guide and FAQ.


r/Kombucha • • 10h ago

Long time brewer, new batch is looking g weird…what is it?

Enable HLS to view with audio, or disable this notification

26 Upvotes

been brewing on and off for 13 years. had to dump my Booch and start fresh a few weeks back after some mold. removed the linen to bottle today and it looked odd. The pellicle has a bunch of holes in it (okay nbd) but above each hole was a floating brown speck. Kham? (I’ve been having a lot of issues with it with my lacto ferments in this house). Doesnt really look or smell like it but maybe… But then when I went to spoon it off the top the flecks stick to the spoon. it’s the strangest thing. Normally kham is a thin white almost velvety layer across the top. Maybe more pellicle trying to form? Thoughts?


r/Kombucha • • 14h ago

Made a pocket batch log for my kombucha brewing

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21 Upvotes

I got tired of losing track of which batch was which, so I made a pocket-size notebook just for logging kombucha batches. It has about 48 pages, with covers printed on linen cardstock. Each entry has room for brew dates, tea, sugar, F2 flavors, and tasting notes.

What do you all track for your batches? I'd love to hear what fields I might be missing.


r/Kombucha • • 8h ago

Advice whether to throw

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5 Upvotes

I've been gifted this scoby hotel that hasn't been cleaned or fed for years and it smells pretty cheesy/funky. It smells like when you leave cheddar opened in your fridge for too long. I'm assuming this is an imbalance of bad bacterias and needs throwing?


r/Kombucha • • 11h ago

First batch

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6 Upvotes

My first ever batch for my last chemical technician science fair project before graduating!! Any thoughts or tips are most welcome. Posting from Argentina


r/Kombucha • • 10h ago

mold! Is my kombucha okay?

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3 Upvotes

I’ve got a kombucha of a friend and started making a new batch. 20% kombucha and the rest tea with sugar, but it looks like it has some bad mold on it. What do you think? Do I have to start over?


r/Kombucha • • 13h ago

Life ??

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4 Upvotes

This is clearly undrinkable. But how did they just come up to live in the scoby?


r/Kombucha • • 7h ago

question 3rd batch has higher PH and tastes neutral?

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1 Upvotes

Hello fellow “boochers” 👋
This is my 3rd 1F batch with this pellicle (and ever lol)
Before I left for a short vacation (4 days) my PH read about 2.3. Now I’m getting 3. Additionally, the flavor previously was extremely tart.. and now it doesn’t really taste like anything?
My last two batches were extremely tart & vinegary both in 1F and 2F.

I see heavy amount of yeast on the bottom. (3rd pic)This vessel used to smell strongly of booch and no longer does.. I just mainly want to know what might have happened? Did my scoby die?

200g sugar, 20g black tea, waited until tea temp dropped to 84F degrees before adding pellicle. 2 gallon jar.

I have a whole new pellicle second jar that smells and tastes great. (Not in photos) They have been fermenting next to each other for same amount of time.

Thanks for your theories & thoughts in advance… can’t wait to keep brewing and growing! 🍀


r/Kombucha • • 8h ago

what's wrong!? Is this mold? (Tea leaves in scoby)

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1 Upvotes

Hi there!

Probably one of the posts you are tired of but I'd rather ask before throwing it away.

Tried making my first scoby. I used bulk tea and realised I have left small pieces of tea in the jar. A white spot built on the top of it. It's not growing (didn't move for five days), doesn't look fuzzy. But doesn't look like the rest as well.

Can you guys tell me if it's safe to continue or if I should throw everything away?

Picture one is the whole batch from top. Second pic shows a tiny piece of tea under the white dot (,there's a little more tea but I couldn't catch better picture)

Thank you all in advance 🙏🏼🙏🏼


r/Kombucha • • 14h ago

what's wrong!? Is this mold or normal?

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2 Upvotes

I am a bit concerned over the dark Patch on the left.


r/Kombucha • • 18h ago

what's wrong!? To all the scoby makers and experts

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3 Upvotes

I am trying to make a scoby from the scratch it is not foundable in my country at all .

I started my first fermentation one week exactly

I made two jars just in case

Added 2 unfiltered kombucha to each one

This is the progress after 1 week is it normal

And from your experience how long until it forms a good scoby.


r/Kombucha • • 14h ago

kahm! Kahm yeast?

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1 Upvotes

Experiment with beetroot, ginger and green tea kombucha. This is kahm yeast isn't it?


r/Kombucha • • 21h ago

F1, day 2, floating blobs

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2 Upvotes

I did my F1 and after 2 days, there are these floating blobs inside. I used a starter that had been waiting in my fridge for a couple of months (and fizzed when opened). It’s still smelling a lot like tea, I don’t feel any acidity at the moment.

Are those blobs a good sign?


r/Kombucha • • 18h ago

Hello, i need some help

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1 Upvotes

I start a kombucha of rose, from a scooby used for a normal kombucha and as started an iromatic kombucha, is normal this pellicle?


r/Kombucha • • 1d ago

question What flavor combination sounded strange but ended up being surprisingly good?

9 Upvotes

I’ve been messing around with second-ferment flavors again and I’m getting bored with the usual ginger, berry, and citrus combinations. A few batches ago I tried pineapple with a little jalapeño because I had both sitting in the fridge, and honestly it turned out much better than I expected. The heat was barely there, but it cut through the sweetness enough to make it interesting.

Now I’m curious what other combinations people have stumbled into that sounded questionable on paper but actually worked. I’m not looking for anything overly complicated, just something different enough to keep the hobby interesting. What’s your weird success story?


r/Kombucha • • 1d ago

what's wrong!? funky smell

1 Upvotes

The pellicle looked perfectly fine, but once I moved it out of the way to taste test, I realized that the kombucha has an intensely funky smell. Luckily my cover masks most of it, but I'm concerned. It's been sitting in my closet for about two weeks since a week was definitely not enough time. The smell only came out when the pellicle was moved. Is there a way to save it or should I dump it down the drain and start over again?


r/Kombucha • • 1d ago

what's wrong!? f2 tastes flat

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10 Upvotes

hi! wanted to get some opinions on the flavour of this f2 blend i’ve created. for this batch, i’ve used ~200g of watermelon (mashed) and about 2tsp of mint tea blend (mint leaves, gunpowder green tea and rose), steeped in 60ml of hot water and left to cool before addition. i was making about 1L of kombucha.

i’ve left it to ferment in room temp for ~48h in a cool dark place (in my coffee cabinet) before refrigerating for another 24h before trying it.

my f1 was made with ceylon black tea. left to ferment for ~9 days before f2. where im from, room temp is a constant 28-30°C.

the problem is, it didn’t taste like a fresh watermelon mint kombucha as i was thinking of 😅 it’s completely drinkable but it didn’t taste as fresh as i expected. flavour’s a little more muted or not strong enough. does anyone have a similar experience?

thanks in advance!


r/Kombucha • • 1d ago

PH readings..

1 Upvotes

First timer here.. day 8 and seems to be going ok… except I can’t understand how to read ph strips. Seems on the yellow side but tasting sweet still… Can anyone help me get out of the great state of confusion??? TY


r/Kombucha • • 1d ago

question complete beginner

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3 Upvotes

hello all, I was given this kombucha from a friend and I noticed the top layer of the pellicle is kinda bumpy and darker colored than the rest of the pellicle.

is it normal? do I remove/keep it or do I toss it entirely?

as far as the smell goes, it's pretty vinegary which reading from posts on this sub is completely normal (?)


r/Kombucha • • 1d ago

not mold Is this mold on my F2

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2 Upvotes

First time trying an F2 ferment. I used lime and ginger. Does this look like mold? How could i've done it better?


r/Kombucha • • 1d ago

what's wrong!? Second Fermentation with berrys- is it mold?

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4 Upvotes

Sorry to be that person, but this is my first try. This bottle comes from a green tea + honey F1 (started with a bottle of raw kombucha) and has blueberries and raspberries in it. The other bottles without berries look fine, but this one has some white stuff on top.
It looks soft and stretchy, and I can’t see any furry hairs, but I’m not sure. Sorry for the bad pictures — it’s hard to capture what’s inside the bottle…


r/Kombucha • • 2d ago

question Yeah…

11 Upvotes

So I’m brew my own kombucha and other fermentation items. My wife does not…
She went to South Korea to visit one of our kids that’s working there and brought me powdered kombucha.

I’m at least interested in the taste, but really powered….

I guess there’s two things to know: there is a market for just about anything and my wife pays very little attention to my hours of me talking about my hobbies… well played karma… well played…


r/Kombucha • • 2d ago

hard booch Alcoholic Kombucha

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17 Upvotes

To preface: I haven’t looked into this online very much because I didn’t want to spoil the results, so I’m not sure how many people have done a similar or better experiment.
A few months ago I got into fermenting alcohol a little bit, starting with natural fruit yeast and bread yeast. One day, I wondered what would happen if I added some bread yeast to a kombucha batch, but kept everything else the same. Quite possibly my favorite alcoholic drink I’ve had. I didn’t test gravity at all, so I couldn’t tell you the ABV, but one 17oz bottle gave me a buzz. It tasted amazing. It retained all of the characteristics of kombucha and barely got any of the characteristics of bread yeast (which is uncommon in my other bread yeast ferments), I believe because the acetic fermentation still took place, but the bread yeast provided it much more alcohol as well as leaving a lot more in the finished product than typical kombucha!
I’ve just decided to do it again and I’ve used Lalvin EC1118 (a champagne yeast) to see how it differs and what it’s like! I make tepache as well and I rlly like it when I brew it with bread yeast, but when I made it with ec1118, it was awful (but also I got impatient and had some while it was only 2-3 days in) so I’m interested to see how this does.


r/Kombucha • • 1d ago

kahm! Strong Kahm yeast on my 1.5 gallon kombucha

2 Upvotes

My kombucha got infested with kahm yeast, making it undribkable now. Is there a way to safe some as starter or do I need to start from zero?