Airlock has stopped bubbling sooner than expected

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

DonBon

Active Member
Joined
Jul 23, 2020
Messages
30
Reaction score
11
Hi all,

My fermenting bucket was set up on Sunday and started bubbling away happily fairly soon thereafter. I set up the airlock incorrectly at first, not realising that the cap was supposed to be pushed on fully - it seemed that clicking it fully in place would seal the airlock and not let anything out.

I realised that the airlock wasn't properly set up and fixed it, but in doing so realised there wasn't as much water in the trap as when I started. (The instructions said the trap should be half full with water.) I boiled/cooled some water, lifted the airlock open and topped up the trap, then fixed the cap in place properly.

Since doing that a day or so ago, I haven't seen the airlock bubbling. My rational brain says that by opening the airlock to add water, I allowed gas from the bucket to escape and it just needs another day or so to rebuild the internal pressure that was lost. My anxious brain says that by opening the airlock, I-KILLED-THE-ENTIRE-BUCKET-OF-FERMENTING-BEER-OH-GOD-OH-GOD-WHY-AM-I-SUCH-AN-IDIOT?!

The fermentation has only been going since Sunday 19th July, so there's no way it should have finished by now (at least, according to my very Beginner understanding) - can anyone confirm what's likely to be going on here?
 
Opening the fermenter doesn't harm the yeast. It sounds like it had been fermenting for 5 days when airlock activity stopped. That's not unusual. Depending on yeast strains, temperature, and other factors, it can even be much faster. Also, bubbles (or lack of bubbles) are not a a good quantitative indicator of anything.

Do you have a hydrometer? Measuring gravity is the only way to know exactly where your attenuation stands.
 
Thanks for the quick reply. I do have a hydrometer, so can have a look at the gravity and see what the story is. The instructions that came with the kit suggested it ought to take up to 15 days for the fermentation to stop and that a good indication that I was approaching that point would be the airlock only bubbling ~every 30 seconds. The temperature is at the cool end of what was recommended also (20C), so I had assumed it would take a fair bit longer than this.

*Shrugs* - I'll go get the hydrometer out and see what it has to tell me!
 
Thanks for the quick reply. I do have a hydrometer, so can have a look at the gravity and see what the story is. The instructions that came with the kit suggested it ought to take up to 15 days for the fermentation to stop and that a good indication that I was approaching that point would be the airlock only bubbling ~every 30 seconds.

Most kit instructions aren't great. Very few beers should take 15 days to attenuate (high gravity beers and/or lagers being possible exceptions) at reasonable temperatures. Your kit instructions have at least two problems, i.e. assigning a number of days for fermentation and telling you to count bubbles.

What were your original gravity, yeast strain, and fermentation temperature?
 
Most kit instructions aren't great. Very few beers should take 15 days to attenuate (high gravity beers and/or lagers being possible exceptions) at reasonable temperatures. Your kit instructions have at least two problems, i.e. assigning a number of days for fermentation and telling you to count bubbles.

What were your original gravity, yeast strain, and fermentation temperature?

I didn't measure the original gravity, I'm afraid. Instructions said it might be useful for future reference, but it felt like there was a bit of hand-waving going on so I didn't pay it too much mind. I don't know what the yeast strain was. Fermentation temperature started at 22oC and slowly dropped to 20oC, where it stayed for maybe the last four days.

The kit I'm working with is this one: American Pale Ale MicroBrewery Starter Kit - you might find information about the yeast strain on that, but I'm not sure from what I can see.

Interestingly, the information on that site is very different from the information in the instruction pack that came with the kit. It lists expected fermentation time at around a week and says the fermentation temperature should be between 16oC and 21oC. That means the bucket has been sitting at the higher end of the acceptable temperature and would mean it's more likely to be ready to go.

Hydrometer has been pulled out for sterilising and will report back shortly!

By the way, how would you normally determine that it's time to check gravity if not by a number of days or watching the airlock? Is there a particular sign to watch for, or do you just have to rely on experience?
 
The kit I'm working with is this one: American Pale Ale MicroBrewery Starter Kit - you might find information about the yeast strain on that, but I'm not sure from what I can see.
`
That's a fairly low gravity beer. It's quite possible that attenuation has been finished for a while.

By the way, how would you normally determine that it's time to check gravity if not by a number of days or watching the airlock?

There's nothing wrong with checking gravity after "x" days. The problem is automatically expecting expecting it to be done in "x" days. An airlock is a sort of general indicator, but can easily give false positives and false negatives. If a fermenter isn't completely airtight (aside from the airlock), fermentation can be happening with little or no bubbling. OTOH, with a well sealed fermenter, you can have bubbling even though attenuation has finished, due to CO2 coming out of solution (off gassing).

Is there a particular sign to watch for, or do you just have to rely on experience?

Yes, experience will give you a feel for what to expect with various gravities, yeast strains, and temperatures, and what that looks like with your equipment. And it's better to give the beer a little extra time in the fermenter rather than not enough. Even though attenuation may be finished, the yeast will clean up certain off flavors. So it's a good idea to tastes your hydrometer samples and make sure there are no off flavors before bottling/kegging.
 
I read through the description of your kit, and it doesn't say what yeast was used. I assume it was a dry yeast. Do you remember the color of the packet? I'm thinking, based on the style of beer, it's probably US-05.

As for checking your gravity, there really isn't a specific time to do so, but I'd wait until the krausen (the foam on the top during fermentation) falls. I typically wait 2 weeks, even though the beer may be done sooner. I'd also recommend that you take readings a couple days apart. If there's any difference between both, wait another couple days and check it again. Keep checking until you get the same reading twice in a row, that's when you'll know it's done.
 
I'm afraid I don't remember. I'm inclined to say it was a silver bag, but I may be wrong.

From what you guys are saying, it's actually maybe a good idea to leave the beer in the fermenter longer than it strictly needs. Is there any downside to leaving it in place for a bit longer, other than the delay in drinking? Presumably there's a deadline on how long you can leave it in place.
 
Probably not US-05 then. It was just a thought.

I'd recommend leaving it for at least 2 weeks. I'm lazy, and most of my beers stay in the fermenter for 4 weeks. I've even left a couple beers in for 6 months, only because I forgot about it. They both came out fine. Low gravity beers probably shouldn't stay in the fermenter for 6 months, but 2-4 weeks is just fine. As VikeMan said, it's better to leave it longer, rather than too soon.
 
From what you guys are saying, it's actually maybe a good idea to leave the beer in the fermenter longer than it strictly needs. Is there any downside to leaving it in place for a bit longer, other than the delay in drinking? Presumably there's a deadline on how long you can leave it in place.

A bit longer is fine. A lot longer, like several weeks longer, is not a great idea. Yeast tend to die and undergo autolysis. At some point this can become noticeable as an off flavor.

Some will say that autolysis "doesn't happen" or "can't happen" "at the homebrew level" (whatever that means). Don't believe it. Technically, it's happened in every batch ever made. How severely and its effect on the beer are what's variable.
 
Ok, so my gravity reading is 1.010, best I can tell. Instructions recommend adding hops at this point and then checking gravity again in a couple of days.

In the longer run, I'm more than happy leaving beers in the fermenter longer, but I think with this one as my very first beer, I just kind of want to get to drinking it!
 
Ok, so my gravity reading is 1.010, best I can tell. Instructions recommend adding hops at this point and then checking gravity again in a couple of days.

Don't be alarmed if you see some renewed airlock activity after adding hops. That's not unusual.
 
1.010 sounds like it's done. Go ahead add your hops, then check your gravity again in a couple days. If it's the same as today, go ahead and bottle it and drink it. It takes about a week for it to carbonate in the bottle, but if you don't mind flat beer, you can start drinking it sooner.
 
VikeMan, I don't disagree that autolysis happens, but I do think it takes a lot longer than "several" weeks.

If you mean "turn beer into burnt rubber or soy sauce," I agree.

I think there are probably many variables that impact how soon autolysis becomes noticeable (including varying taste thresholds). But it's happening all the time. It's even happening in liquid yeast packs sitting in refrigerators. (If you've ever looked at yeast under a microscope, you've probably seen the effect on some cells.)

One of the subtle things autolysis does is increase the beer's (or yeast slurry's) pH, potentially impacting flavor without being an obvious "off" flavor per se. Some breweries use the (high) pH of yeast slurries as an indicator that the slurry should not be used.

So, while I don't obsess over autolysis, I also try not to tempt fate.
 
One of the beers that I forgot about and left in the fermenter for 6 months was a 12.9% ABV barleywine. That beer won two awards, the first was a brew club competition, and the other was a BJCP sanction competition. In the BJCP competition, it won first place in the category, and second place Best of Show. Being that high in alcohol may have prevented much autolysis, but it made me realize that it's not as bad of a problem as most say it is.

Either way, 2-4 weeks in the fermenter isn't a problem.
 
Hello new brewer.
The #1 advise to any new brewer.... RELAX.
Like all of us one were, new brewers tend to worry way-way too much.
Beer making is more resilient than you think. Mistakes can happen and the beer still comes out great.
As long as you follow basic procedures, clean stuff well... pay attention to temperatures when fermenting - you have an outstanding chance of perfectly good beer. Mistakes or no mistakes.
Unless you are brewing for competition...fretting over every detail is not necessary.
Relax... have fun.

Note... I use vodka in the bubbler. It has many advantages. First of course is that it sterilizes everything it touches. Second, it doesn't foam or bubble up. 3rd and most important, when you are moving the carboy around and some of the liquid in the bubbler goes into your beer - there is exactly zero chance any nasties get in. Plain water gets "germy" after awhile.
 
How did that turn out for you?


back in '96? with a serious case of alcoholism! my 18 year old brain, kinda just clicked, and said huh it's that easy to make my own huh? :mug:

(but joking aside, the only reason i brew beer is because it's cheaper)
 
49dxmw.jpg
 
Back
Top