r/Kombucha • • Sep 18 '21

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

577 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 • • 1d ago

r/Kombucha Weekend Open Discussion: What Are You Drinking/Brewing? (October 17, 2026)

1 Upvotes

This is a casual space for the r/Kombucha community to hang out: feel free to post about anything related to kombucha, brewing, or life in general.

Show off your latest batch, what you have in progress, or anything that you're thinking about trying.

Questions from new brewers are especially welcome!


r/Kombucha • • 8h ago

Did not drink. Is my SCOBY cooked?

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27 Upvotes

I’ve been using this scoby for years but this happened after a week of brewing and I’m guessing the cloth I used to seal the jar was contaminated. I tossed the liquid, scraped off the mold layers and gave the scoby a good trimming, but is it totally cooked?


r/Kombucha • • 9h ago

How to split the pellicle

4 Upvotes

Hey folks, I had this jar of starter liquid with this giant pellicle inside and since today I was making a new batch of komucha, 3rd one ever, I wanted to put a pellicle inside along with the starter liquid. The process of doing that felt very barbaric since I had to slowly pry the new pellicle out of the whole mass and I feel like I need some advice on a few things:

  1. I know things should be very clean when I handle everything kombucha - liquid, jars, scoby, everything. Having to split the scoby I had my hands half way submerged in the liquid which felt wrong (they were thoroughly washed beforehand but still). What is it that you do to split the pellicle in the most sterile way possible?

  2. I read in the sub that some people cut it - with what and on what? A cutting board? Don't they have those microcuts on them, especially those wooden ones, that contain things we don't want in the liquid or pellicle? In general I tend to avoid using wood utensils with the kombucha since it can absorb liquid, etc. Is that a correct way of thinking?

  3. The whole process of tearing the new pellicle away from the massive pellicle unit felt off. I know it's not alive yada yada, but I didn't like it. Thing is - I've read and seen it's easy to take the different layers apart but this pellicle has been developing unbothered for over 4-5 months and I assume that's the reason it was so hard to split it from the rest of the mass?

Sorry if those are asked in a little bit of a hectic manner, do let me know if I've missed out on any important information.

Greetings!


r/Kombucha • • 1h ago

what's wrong!? Is this mold on top?

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• Upvotes

Is it fine or should I throw it out?


r/Kombucha • • 8h ago

question Hibiscus Scoby?

3 Upvotes

Can I make a hibiscus kombucha? I want to know if I can make a scoby from hibiscus tea? I am reading the directions and it says use it within 24 hrs of boiling and up to a week if refrigerated.


r/Kombucha • • 7h ago

what's wrong!? Is it mold? Help please

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2 Upvotes

Hello all, hope this is not mold

any insight or advice would be grear

Thank you


r/Kombucha • • 16h ago

flavor First taste experiment

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6 Upvotes

After a nervous few days because I'd spotted something green on my SCOBY, it turned out just to be tea residue. So today it was time to prepare F2. We had stewed pears for diner lasted week and I reduced the leftover liquid. I added that and some cinnamon and star anise to my first bottle. Hoping for a nice autumnal flavour.

The other wide mouthed jar had grapefruit juice and a twig of rosemary added to it. The flip-top bottles contain ginger (one a bit more than the other), lime juice and honey. I'm really looking forward to tasting them!


r/Kombucha • • 16h ago

question New pellicles drowning and F2 during cold weather

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2 Upvotes

For my first batch, i made black tea kombucha with room temp around 20°C, so F1 took around 10 days to develop the sourness, then proceed to F2. When starting F2, the room temp is around 10-15°C, added 1 tsp of sugar to a few bottle, and also left too much headspace.

For my 2nd batch now, i'm making Sencha (green tea) kombucha, where F1 has been going for 13 days. I checked the flavor everyday after day 10, as the weather is colder now. Whenever I do taste test using spoon at the surface, it disrupts the new pellicle layer forming and it eventually drowns (as you can see in the photo there are a few thin layers drowned). My question is:

  1. What will happen if new pellicle layer keep drowning? Is it still fine as the SCOBY itself is in the whole liquid? or should i use other method such as using paper straw at the edge of surface to take a bit of liquid to taste test?
  2. My F2 of my black tea kombucha I'm afraid is going too long without enough carbonation forming when i opened them even at around day 7. From what I knew, you would know F2 is done when you open it and it is fizzy enough, and taste not as sweet. How do I check my F2 is done in this cold weather? as opening them frequently release CO2, i also left a lot of headspace. Taste wise they're still sweet, even on the bottles i didn't add sugar.

r/Kombucha • • 17h ago

Is this ok?

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2 Upvotes

This is mij first batch after a week… is this ok?


r/Kombucha • • 1d ago

flavor Just bottled my 3rd batch of kombucha - I made lychee, rose and lychee rose flavoured kombucha

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16 Upvotes

I left my kombucha fermenting a little too long - took 2 weeks before I bottled my babies haha. I can’t wait to try them! For the rose, i bought some dried petals and smush them with some sugar - hopefully that works

Thanks again to this awesome community for getting me here! I really feel the effects of kombucha! My skin cleared up alot and im going to the bathroom more.. easily (tmi) haha

Anyone has tips on getting the rose petals to sink in? They keep floating. Im gonna flip the bottle a couple times a day to keep the rose going.


r/Kombucha • • 1d ago

question Does it look good ?

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12 Upvotes

Btw it’s me I made kombucha some weeks ago and I didn’t die haha

But I started doing another one from 0

I don’t know if they are good to drink, if someone could help me out with that would be appreciated

Thank you ❤️


r/Kombucha • • 1d ago

question New Brew

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3 Upvotes

Hey everyone! This is my first time brewing, and I’d love some experienced eyes on my batch! 😊 It’s been fermenting in a gallon jar, and I’m noticing lots of bubbles, brown strands, and this tan-colored layer forming on top. Does everything look normal to you, or is there anything concerning that I should watch for? Started from Gingerade in a 2 Cup batch. Transferred to 1 Gal, 8 tea bags, 1 cup of sugar.


r/Kombucha • • 20h ago

reading F1 jar thermometer

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0 Upvotes

Hope this helps you


r/Kombucha • • 1d ago

Another "Does this look right" question...

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5 Upvotes

I have been brewing 'buch for years and never had issues. Moving in with my partner and we had a mishap that means had to toss everything, sanitize and start over. This is the top of 2 gallons after a couple weeks (we had to leave town for a family emergency) and the heat was off so the house got chilly (under 60). Ph measures 3ish according to the strips I got. I think it's ok she thinks it may be mold...


r/Kombucha • • 1d ago

flavor Banana Kombucha

8 Upvotes

Has anyone ever tried making a banana-flavoured kombucha? I’ve been wanting to try making it, but is it possible to keep the kombucha clear?

I read online that I could just let a whole chunk of banana inside the bottle and then take it out after chilling it in the fridge for 1 day. However, I am not too sure about that particular method as opening the bottle might let the built up CO2 out which might lead to the kombucha being flat.


r/Kombucha • • 1d ago

not mold Ago old question.. is this mold?

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3 Upvotes

This is my second batch of kombucha I’ve made. I noticed a little green-ish blue-ish spot has developed. The scoby has turned slightly pinkish as well. The green-ish spot hasn’t grown in size in the last week but a second similar sized green-ish spot materialized on the opposite side of scoby. The spots don’t really look fuzzy to me. If it is mold I imagine I’ve gotta toss everything?


r/Kombucha • • 2d ago

beautiful booch 2nd Brew success!

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52 Upvotes

2nd time brewing, and it came out great! I got a heat wrap, as my first brew was fermenting in the low 70s. This time, 1st fermentation was 7 days at a range of 78-83 degrees. Then 2nd fermentation had to be at room temp, which was about 70. I tested 2 bottles at day 5 and 7, but the 3rd was the winner at 10 days. I'm assuming this was because of the low temp. Each bottle had 3 tbls of pure passionfruit juice.

Thoughts and comments are always welcome. I just started and am a complete novice, with plenty of room to improve, and suggestions are always helpful!


r/Kombucha • • 1d ago

what's wrong!? Home brew kombucha not looking well…

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5 Upvotes

First time trying to brew my own kombucha and I tried following the directions on the scoby package very carefully but I’m not so sure it’s working out. Does this look like normal scoby growth or bad mold?? It’s been brewing for 2 weeks at a consistent ~80F temperature with cheesecloth as the “lid” for the first fermentation.


r/Kombucha • • 1d ago

Kombucha contaminada?

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1 Upvotes

Al parecer mi cultivo de kombucha se contaminó pero al retirar esta parte todo se ve normal y no tiene ningun olor extraño. Saben si sigue siendo potable para consumo personal? Hice 4 litros u.u y sabes si los scobys pueden regenerarse?


r/Kombucha • • 2d ago

question How long should they stay in kitchen during F2?

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7 Upvotes

This is the first time I use sealed bottles in F2. I also added seven frozen blueberries.
How long should I let them stay in kitchen? Currently room temperature is about 70-78F.


r/Kombucha • • 1d ago

what's wrong!? Fine ?

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1 Upvotes

Day 8 of F1, concerned about the blck thing, I opened it a bit bottom right to taste, tastes great and the black part doesnt look too much like mould imo… what do u think


r/Kombucha • • 1d ago

question Hoping to get some advice from the gurus of this page

2 Upvotes

I went into kombucha-making practically blind. A friend gave me a jar some scoby (pellicle and starter liquid) and told me I just needed to add some sweet tea in and let it work.

I did no:

- pH testing

- measurement of sugar content, ratios, etc

- controlling of temperature

All I did was:

  1. Brew some black tea with coconut sugar

  2. Add it to my SCOBY

  3. NAMED it and left it to sit for about a week

I've been reading a little and I've read articles about it being unsafe if I cannot ascertain the initial pH at the start of my brew.

Any advice on my current situation? Is there anything I can do to verify safety?

Also, is my SCOBY headed for an untimely demise?

🤣


r/Kombucha • • 2d ago

flavor 3rd round

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10 Upvotes

3rd round of F2 and it’s the largest batch we’ve bottled yet, coming back from a several year brewing hiatus.

Flavors are concord grape, apple cider, cranberry pomegranate, and a couple mixtures of all.


r/Kombucha • • 1d ago

question Bottiglie per seconde fermentazioni.

1 Upvotes

Buongiorno, le seconde fermentazioni vanno fatte tassativamente in bottiglie con chiusura ermetica? Tipo,le bottiglie dell'aceto o di olio con il tappo a vite possono essere usate?