Stalled Fermentation?

[Gee Tee]

Hello my fellow brewsters. I’ve been brewing for about a year and thought I was getting the hang of it, but seem to have hit a snag. I’ve been brewing up a batch of Northern Brewers West Coast Radical Red and Innkeepers with Wyeast 1272 American Ale II Yeast (60 - 72F) and
Wyeast 1469 West Yorkshire Ale Yeast (64 - 72F). The smack packs were bloated when I pitched so I assume the yeast survived the transit. I pitched on Saturday, Sunday saw some gentle activity in the airlocks, but have seen little activity since Tuesday. Both buckets bubble though their respective airlocks and now bubble once every 40 - 60 secs. The room temperature has been around 64 which should be in the 60/64 - 72F range. Any thoughts / suggestions?

 

[VikeMan]

Any thoughts / suggestions?

How long have they been in the fermenters? Have you taken any gravity readings? Airlock activity is not a good quantitative measure of fermentation, because bucket fermenters can be leaky.

 

[KeizerBrewr]

What @VikeMan said. Also, those temps are a bit on the chilly side for a good fermentation. I pitch low and let them self rise and hold between 65-70F, depending on style, yeast and ester profile I'm looking for. Raise the temperature to 67 degrees and see what happens.

 

[Gee Tee]

How long have they been in the fermenters? Have you taken any gravity readings? Airlock activity is not a good quantitative measure of fermentation, because bucket fermenters can be leaky.

Thank you VikeMan. I put it in the fermentors this March 6th. I've fermented several batches with them and they don't leak as far as I know. I've not taken gravity readings as I don't want gunge up the spigot or let air in. Here is a pic of one of the buckets. You can see the krausen has receded. Are theses yeast strains delicate? Any chance they might have died if the temp dropped below 64? In the rare chance that it did it wouldn't have dropped more than 2 degrees. I am completely baffled..

 

[Gee Tee]

What @VikeMan said. Also, those temps are a bit on the chilly side for a good fermentation. I pitch low and let them self rise and hold between 65-70F, depending on style, yeast and ester profile I'm looking for. Raise the temperature to 67 degrees and see what happens.

Thank you KeizerBrewr. I just did that a couple of hours ago and will see. If it is chilly, does the yeast die or just go to sleep? I'm pasting what I wrote in VikeMan's reply and putting a pic to show the krausen drop in case that helps. "Here is a pic of one of the buckets. You can see the krausen has receded. Are these yeast strains delicate? Any chance they might have died if the temp dropped below 64? In the rare chance that it did it wouldn't have dropped more than 2 degrees. I am completely baffled.."

 

[KeizerBrewr]

No, yeast are surprisingly resilient, tough little buggers. When they get too cold, they go to sleep. Think of them as a reptile; when they get too cold, they get slow or sluggish, in some cases stall. It does look like the krausen has receded, but that doesn't mean they're done. I just had a brew day on a Best Bitter Sunday morning, the yeast went crazy, and now, over 48 hours after pitching, the krausen has receded, but I still see activity in my fermenter (I have a Catalyst, so it's easy to check activity). Don't open the lid unless you're going to thief a sample to check gravity or you're going to bottle. Don't panic yet, just warm em up a bit and see what happens. Give it 24 hours.

 

[VikeMan]

Any chance they might have died if the temp dropped below 64?

No.

I've fermented several batches with them and they don't leak as far as I know.

When they leak, they tend to leak through the lid seal. Lots of them don't leak. Until they do.

 

[Gee Tee]

No, yeast are surprisingly resilient, tough little buggers. When they get too cold, they go to sleep. Think of them as a reptile; when they get too cold, they get slow or sluggish, in some cases stall. It does look like the krausen has receded, but that doesn't mean they're done. I just had a brew day on a Best Bitter Sunday morning, the yeast went crazy, and now, over 48 hours after pitching, the krausen has receded, but I still see activity in my fermenter (I have a Catalyst, so it's easy to check activity). Don't open the lid unless you're going to thief a sample to check gravity or you're going to bottle. Don't panic yet, just warm em up a bit and see what happens. Give it 24 hours.

Yeah... I got the temp up to 70ish and swirled the buckets around a bit. There is the occasional bubble coming through the airlock so something is happening. All the other yeasts I've used have gone crazy on pitching and bubble like a soda fountain so I might have a skewed experience with yeast activity. Is yeast as resilient to the heat as the cold?

 

[KeizerBrewr]

I get it. All yeast are different, for the most part on how they ferment and react during fermentation. But yeast in general don't mind being warm, unless it's lager yeast, those buggers are temperamental. I'd give it some time. I wouldn't worry too much about the heat, that being said don't go too far with it as it will stress them out and cause some off flavors. Just bump to the top of their temperature range and let it ride.

 

[VikeMan]

Is yeast as resilient to the heat as the cold?

You would have to get up to some really high fermentation temperatures (like 100+) before the yeast would mind, i.e. before you would start to impair fermentation. That goes for ale strains and lager strains. That said, there would be undesirable off flavors. But yeast don't care about taste.