Temperature Drop causing Fermentation to Stall?

Hi all,

Just introduced myself (https://www.homebrewtalk.com/f29/hello-brooklyn-183261/) and already have my first question:

I started out with a Belgian Strong Ale and pitched my dry yeast when the wort was at around 80F (I know I should have waited for it to go further down but it was already 3am and I was falling asleep). Fermentation began shortly after and bubbles were going strong with a nice Kreusen settling on top of my beer.
However, a day later I dropped the temperature to around 70F after noticing how hot it was in my apartment and kept the temperature at that level. Now 1.5 days after initially pitching my yeast, it seems like all fermenting activity has stopped completely. No more bubbles and the Kreusen has disappeared and no more activity inside the Carboy as well.

Should I increase the temperature again or should I even consider re-pitching? I don't own a hydrometer to check gravity but I'm almost certain that nothing is happening anymore.

Thanks in advance!

Buy a hydrometer. The only real way to know if your beer is finished is if you have a hyrdrometer reading. I would concider it the most important piece of equipment I own for brewing.

It's possible that a high initial temperature caused the yeast to be very active, thus finishing your fermentation quickly. Still, I'd allow the beer to sit for a few weeks so the yeast have an opportunity to clean up any off flavors that may have been created by the high temps.

without a gravity reading, its difficult to tell whether you have a stalled fermentation or a finished fermentation. If you feel confident enough about your tasting skills, you could taste a sample to see if its over sweet or has a thick mouthfeel (indicating a stuck fermentation).

Makes sense, I'll get a hydrometer this week then.

More out of curiosity, is it possible that the yeast stopped fermenting because I went from my initial 80F to low 70s and it didn't like the rapid temperature drop?

It's possible- but not very likely that the temp change caused the ferment to be "stuck".

Barring other things, it may just plain be done. Pitching at high temps can cause a quick ferment, but at the cost of some slightly "off" flavors. However, it's still probably beer, and probably still better than BMC.

However, I would think it didn't brew out completely yet (possible, but not likely), so we have another scenario- and my best guess as to what you have with the info here-

1. High pitch temp equaled an extremely vigorous start for the yeast- heavy krausen, heavy CO2 production. Did a major amount of brewing in a short time.
2. Bringing the temp down brought the yeast down to a reasonable pace, so now it's cruising along v-e-r-y slowly compared to before.
3. However, slowly equals no visible activity- you'd see no bubbles, no krausen, etc. The airlock may be releasing once every few hours, which is normal towards the end of a brew.
4. So, there's probably nothing majorly wrong here.

Little things could also throw you off- minor leak on the seal of the carboy, for example.

Hence the hydrometer. It will tell you exactly where you are at.

So, my suggestions.
1. Don't stress over it. Just ignore it till you can get your hydrometer.
2. Once you have it, check the gravity over three days. If it hit the FG and it's the same all 3 days, it's done. If it's still dropping, let it brew. Unsure what your readings mean? Post them and then a diagnosis can begin.

To be honest, I don't really think there are that many "stuck fermentation's" with most yeasts. I think a lot of it is people that don't know what to expect and don't understand the ingredients they are working with. I'm sure your beer will be fine.

Thanks Guys, this was really helpful. And thanks for the detailed response Vhampyre, everything makes perfect sense the way you described it. Looks like it slowed done considerably, to the point where I can't detect any fermentation. Will get a hydrometer asap and post my results.

Seems like this is one of the most common newbie questions/concerns but I just couldn't help but ask

Went to my LHBS and bought a Hydrometer. The reading was 1.020.

I also tasted the beer and it was good, not sweet so I would assume that fermentation is almost done (or done) and that's why I don't see any activity. Does that make sense?

Since they beer already tasted pretty good - given the fact that it was warm w/out carbonation - would it make sense to bottle it soon?

Check tomorrow, or better yet, the day after. See what the reading is then and post. No reason to rush. Yeasties will be available to carb for quite a while, and hurrying doesn't help.

The rule of thumb is minimum 3 weeks in fermenter, then 3 in the bottle for the best beer.

Being a first beer, and understanding that patience is impossible, lets verify the brew is done- check again tomorrow.

Also, fwiw, I don't think it's done yet. Still a fairly "thick" brew at 1.020.

What's the recipe's SG/FG?

vhampyre said:

Also, fwiw, I don't think it's done yet. Still a fairly "thick" brew at 1.020.

What's the recipe's SG/FG?

Click to expand...

Being a belgian strong ale, I'm going to assume it started out with a moderately high gravity. 1.020 is a good finish for that. I'd still make sure to check it a few days in a row to be sure though. You don't want bottle bombs.

Not sure about the OG/FG, only have the ingredients and alcohol content:
Ingredient Mix for 1 Gallon of Bel-Gin Strong Ale
Ingredients Malted Barley Blend, Hops, Yeast, Juniper Berries, and Coriander.
ABV 7.25%

Since the beer didn't taste sweet at all (I did add a good amount of Candi Sugar before fermentation) It would make sense for it to be finished. Will do more gravity readings over the coming days though.

A beer being sweet has nothing to do with it being done fermenting. And at 1.020, I would expect it to be fairly sweet.

Just took another reading (two days after the first one) and it's still 1.020. I'm hoping this is FG or is there a possibility that my fermentation stalled b/c of the initial 80F I had in my carboy for a while?