First Brew Still Fermenting Away - When Is It "Done"

[lanev]

My first brew (an amber ale) has been in the fermenter for 10 days now and is still bubbling about every 90 seconds. It's been doing 90-ish seconds for several days now. At the start, I used yeast nutrients and oxygenated the wort, and it was bubbling like mad in under 15 hours which lasted maybe a couple of days before starting to really slow down.

I've got my carboy in a mini-fridge keeping the wort/beer at 67 degrees. I've not tested current gravity as I figure it's not going to change the final gravity when fermentation is done and I don't want to risk introducing possible infection. My plan is to cold crash it at the end for a couple of days before I transfer to a keg.

I understand that when fermentation is done I should let it sit for a few days to let the yeast clean-up any potential off-flavors (diacetyl rest). While I'm anxious to be able to try it, I'd rather wait for a tasty beer at the end than push it and have less than desirable results.

So, finally, my question: When do I consider fermentation to be done? How long should I expect between bubbles, or should there just be no more bubbles?

 

[brew703]

You need to check the gravity. Most people do it in consecutive days to verify the gravity is the same. Most yeast is done within a few days. I cant say I've ever had yeast still working some at 10 days.

My last brew ( 2/22) I used S04 (rehydrated) and as of Monday there was little activity remaining. I usually don't worry about checking gravity until at least 10 days.

If you are still getting activity at 10 days let it go a couple more days then check your gravity.

 

[Jag75]

Patience is a good thing . I for one am a 3 week kinda guy when it comes to fermentation. Airlock isnt a sign of active fermentation. Co2 released from the beer goes out the airlock. The only way to tell is with a hydrometer. I will let the temp come up to 70 on day 5 for diacetyl clean up ect...you can keg or bottle at your time frame . Some people are packaging within 7-10 days but I dont . Experiment and see what you like . Yeast will do what it wants on it's on schedule, just make sure it's done before bottling.

 

[lanev]

Thanks guys, appreciate the advice!

 

[lanev]

I measured my gravity and its sitting at 1.010 so it looks like it's done. I'll give it another day or so before I cold crash. I started at 1.040 so ABV sitting close to 4% and it tastes good. Not bad for the first successful brew!

 

[Buick Beer Gardens]

3 weeks.

 

[McKnuckle]

"When is it done?" Homebrewers vary greatly on this question. First of all, at 10 days your fairly low gravity beer is done fermenting. It was probably done at 4 or 5 days. But it now needs to be conditioned so it will taste good, and that takes a good 2 weeks, preferably in the cold.

Some brewers will just leave the beer in the fermenter to accomplish that, either at room temperature or by cold crashing in a fridge. But if you are using a keg, you have the option of transferring it pretty much right after fermentation and a 2-3 day yeast clean-up period. Instead of spending extra time conditioning in the fermenter, you'll let that happen in the keg. Benefits? You can carbonate it and chill it at the same time! So in two weeks (or less, if you insist), you can be drinking the beer without much compromise. It will continue to improve for a while longer in most cases.

Since you're not dealing with bottles, any small amount of sediment that you inadvertently transfer to the keg, or which settles there during conditioning, will just get dispensed at the beginning - and then it's gone forever - leaving you with clear beer. It's not a concern or something to obsess over. I would not cold crash in the fermenter first, because the temperature change creates a vacuum that will draw in oxygen. Just do it in the keg.

You are smart to not be mucking with it prematurely! That's impressive and unusual for a new brewer... congrats.

 

[lanev]

Thanks, McKnuckle. I started cold crashing in the fermenter late yesterday before I read your post. In the future, I think I'll do that in the keg as you suggested. If nothing else, it frees up the fermenter for the next brew.

My thought process has been to leave it in the fermenter for 2 weeks and then a week in the keg to finish carbonating and conditioning. The 2 weeks is getting shaved a bit this time around due to business travel but it will spend the extra shaved days in the keg so it should still be all good.

I appreciate the kind words for a new brewer. I've been reading about brewing for far too long - I tend to over-analyze everything - trying to make sure my setup is better than just good enough so I have a better chance at success. As much as I'd like to monkey with it, I'd much prefer the time and money invested to pay off with a good product. I was pleasantly surprised by the sample I tried after taking my gravity reading yesterday. I've got high hopes for it when it's carbonated and chilled!

Now, I just need to work on getting more sugars from my grains to get the SG up where it should be.

 

[McKnuckle]

If it makes you feel any better (or worse?), I'm on my 116th batch and I either do something new or learn something nearly every time.

Brewing is a very rewarding hobby because it touches on many disciplines - culinary, chemistry, biology, engineering, mathematics, history - and of course sensory. It's also something you can read about ad nauseum, but which stubbornly presents you with empirical results that are often more valuable than theory.

 

[Buick Beer Gardens]

If it makes you feel any better (or worse?), I'm on my 116th batch and I either do something new or learn something nearly every time.

Brewing is a very rewarding hobby because it touches on many disciplines - culinary, chemistry, biology, engineering, mathematics, history - and of course sensory. It's also something you can read about ad nauseum, but which stubbornly presents you with empirical results that are often more valuable than theory.

Plus you are making beer. It is a win/win situation.

 

[mattdee1]

I'm in the camp of kegging after 7-10 days, pending availability of free time to do it. My standard used to be 14-21 days, but based on 10-12 batches using the shortened schedule I see no downside to it, so I go with it.

No cold crashing for me - I don't want to risk sucking in oxygen and I can't be bothered to implement measures to prevent it for the sake of an unnecessary step.

I like your thinking on not doing a gravity sample just to "check." You can grab a FG sample when you package the beer if you like, but opening your fermentor for a frivolous check - something I used to do every batch, by the way - just seems silly to me now. If you're waiting 2 weeks or more, it would take some pretty strange circumstances for the beer to not be done fermenting by then.

On that note, the following criteria usually indicate a finished fermentation for me:

- has it been at least 5 days since yeast pitching?
- has the temperature been controlled?
- is it a yeast I've used before and am familiar with?
- am I confident my pitch rate is in the right ballpark?
- do I see evidence of a krausen layer that has risen and fallen?

If the answer to all of these questions is "yes" then I can almost take it to the bank that the beer is at FG and I can package at any time. By the 7-10 day mark, I'm usually comfortably in the "yes" zone for all of these questions.

Now, there have been some situations where I've hit day 10 and have gone to keg the beer and I've noticed a krausen layer that hasn't completely fallen down yet. If that happens - which is rare - I wait. BRY-97 in particular is a yeast that seems to like to drag its feet, and usually calls for at least 14 days in primary.

 

[KookyBrewsky]

My second “disastrous” brew that I botched has subsided a bit, visually. It’s still got a bit of bubbling from the blow off tube.

How many days should one expect vigorous fermentation? Where you can see activity shooting every which way inside the fermenter, quite wildly?

Second, when I had to release pressure I oozed out quite a bit of foam and maybe krausen, not sure of the difference... will the yeast be able to multiply to make up for any yeast that oozed out? Or do they stop eating / multiplying at some point even with sugars left?

 

[McKnuckle]

Yeast multiply during the lag phase, which is the period immediately after pitching where they uptake oxygen from the wort. They are no longer multiplying during active fermentation. Vigorous ("wild") fermentation is usually only 2-3 days.

There are plenty of suspended yeast cells even with a modest amount of krausen loss, so don't worry about it.

 

[brew703]

All yeast perform differently. For me, my beer is usually done no later than day 5, most times before that. My last brew was on 2/22 and it fermented vigorously for 3 days then stopped. I normally leave it in my fermenter for 10-12 days at which point I will cold crash (using a mylar balloon filled with CO2) or just transfer to keg. I didn't check the gravity until last night which was 1.008 (OG was 1.057). This batch over- attenuated by 6 points. Not sure why but that raised my ABV by almost 1%.

 

[jtrux]

Is the recipe a known recipe or did you craft it yourself? If it’s a known recipe then you should know where the FG should land. Leaving the beer on the cake for 3 or so days after FG, never hurts and allows time for cleanup. At that time if your kegging you can probably go ahead. If bottling I’d take another reading to make sure FG didn’t change (you don’t want bottle bombs).

 

[KookyBrewsky]

Is the recipe a known recipe or did you craft it yourself? If it’s a known recipe then you should know where the FG should land. Leaving the beer on the cake for 3 or so days after FG, never hurts and allows time for cleanup. At that time if your kegging you can probably go ahead. If bottling I’d take another reading to make sure FG didn’t change (you don’t want bottle bombs).

Yes, it’s a known recipe and I was very close to OG, but who knows how my temps and fermentation went. Will probably take a FG at two weeks or so as to not disturb anything since it’s my first brew.