top of page

What to expect during 1st fermentation

So, you’re waiting for your kombucha homebrew to ferment. It’s an exciting time! It can also be really nerve-wracking if you’re not sure what to expect. So here’s what I’ve consistently been able to observe in my homebrews, so you can use it as a point of reference.

Remember: Everyone’s SCOBYs are different and a lot of variables can cause changes, but usually, the best thing to do is just wait it out and let it do its thing.

People are most afraid of mold happening during 1st fermentation (F1), but those fears are largely unfounded and blown out of proportion. Check out my Real Talk: Mold post for more info.

So don’t jump to the worst conclusion if things look a little weird as your brew progresses. Fermentation is a strange and uniquely beautiful process. Give it the time it needs to do it’s thing! More often than not, it’ll turn out just fine.

Here's what to expect during F1


  • When you first put your SCOBY into your sweet tea in the brewing vessel, it might sink. Or it might float. Both are OK. Oftentimes, it’ll end up making it’s way to the top of the brewing vessel in the next few days, where it’ll conjoin with the new SCOBY that’s forming. But if that doesn’t happen, that’s just fine as well.

  • At around day 3, you’ll start seeing some opaque white specks dot the top. This is usually when people get nervous, thinking it’s mold. It’s really just the SCOBY starting to get into formation. Don’t agitate the vessel because it could inhibit SCOBY growth or cause your new SCOBY formation to sink. That won’t hurt the brew, but it could freak you out if you’re not familiar with the process and wondering if something went wrong because your SCOBY doesn’t fully form.

  • By day 4-5 you'll likely see a new, thin layer of SCOBY grow across the top. It’ll take the shape of whatever vessel you put your liquid in. If you don’t see a SCOBY yet, it may be because your average room temperature is lower than mine is. It doesn’t mean something has gone wrong. Just give it more time. Sometimes a new SCOBY won't form at all, or sometimes it'll be super thin. That happens to mine sometimes in the winter. In that case, you should just base doneness on how your brew tastes.

  • You might see some brown stringy yeasty bits. They might look scary or “dirty” but that yeast will actually help make your kombucha nice and bubbly. It’s your friend. No need to clean it off or remove it from your SCOBY.

  • You might also see black specks trapped in/on the SCOBY if you didn’t fully strain all the tea dregs out. That’s OK. They usually look like little poppy seeds embedded under or throughout the SCOBY. If you’re using loose-leaf tea and a big leaf/twig got stuck in there, that’s not a huge deal too.

  • If your SCOBY starts pushing out of the vessel, that’s OK. Just push it back down. Don’t worry if you think it’s been hanging out in the air a few days. It’s OK. This sometimes happens as carbon dioxide starts building up in your liquid under the SCOBY. It can sometimes push the SCOBY out of the liquid. It can also happen if your brewing vessel narrows at the top — the SCOBY can bump up against the sides as it grows. In either case, next time, you can just push it down or try to use less liquid in your brew vessel.


  • The liquid will lighten in color over time.

  • You might see some cloudiness at the bottom of the vessel where the yeast settles. That’s totally normal — just make sure to stir your brew vessel well to distribute this yeast throughout the liquid before you bottle it.

  • You might notice an acidic/vinegary smell coming from your brew vessel. That's totally normal and a sign that your brew is fermenting properly!

  • Mold is pretty unlikely as long as you take steps to do this properly. If you’re really concerned about mold, though, I’ve got a whole video and a blog post dedicated to it. Check ‘em out here.

  • You can monitor the average room temperature really easily using temperature stickers. Ideal temperature is mid/high 70s, though the 65-85 range works too. The cooler it is, the longer it’ll take to get more acidic. So just adjust your brewing time (a.k.a. waiting length) accordingly. In the winter, it might take 2 weeks instead of a week and a half to get to the right level of acidity that you like. In the summer, it might only take 7 days.


But in the meantime, don’t stress about your brew. What it needs most is time, so the less you futz around with it, the more it can just do its thing.


If you’re antsy and just want to consume as much kombucha content as you can (I hear you!), be sure to poke around this website to learn more about the brewing process and watch the videos on the You Brew Kombucha YouTube channel.

Find out how to tell when your 1st-fermented kombucha is "done" and ready to flavor + bottle here.

SCOBYs can take a variety of shapes and colors. If you want to see a sampling of healthy, but interesting-looking cultures from fellow home brewers that shared them with me, you can go here

bottom of page