Post-fermentation - when to move the fermenter to a warmer spot?

[Veronis]

Heya ladies and gents,

I brewed an all-grain Irish Stout on Sunday and pitched a starter or White Labs Irish ale yeast - OG 1.062 (no lactose). I don't have a fridge, so I use an 18-gallon bucket as a swamp cooler, and maintain temps using small amounts of ice and frozen 12-oz water bottles.

Fermentation took off in a few hours, and temp maintained 65-67 through today.

The krausen started to drop yesterday afternoon, and today has mostly dropped out; it was a very bubbly fermentation for the first couple days but it never climbed up the fermenter and into the blowoff tube.

It's only day 3, and right now there's about 1 bubble in the blowoff every ~4 secs.

The swamp is currently 66.2 degrees F. The landing at the top of the basement steps is always 70-71.

To finish primary fermentation, how do you know when to move the fermenter to the warmer temps? I don't know if it's too soon, or if once krausen starts dropping you can move it to slightly warmer temps immediately.

 

[Math0]

I believe you do not have to move to a higher temperature room to finish fermentation. When the fermentation gets stuck, it would be a good alternative to try that. Basically, the higher temperature will improve the fermentation speed and may result (if it is way too high) in off flavours.

On the white labs website, they say the optimum ferment temp is 65-68F. I think you should leave it like this!

 

[hellawaits77]

I wouldn't bump the temps up unless you are absolutely positive you've stalled. If you're only on day 3, you've got quite a while left to go. Just be patient and let the yeast do it's work!

 

[gr8shandini]

What makes you think there's a problem? Have you had beers stall out in the past? After 3 days, the primary fermentation phase is probably just about done. It's perfectly normal to have very little visible activity at this point.

If you're really worried, I'd take a gravity reading. If you're way above your target FG, go ahead and let it warm up to room temp. If you're close, just let it go as-is.

 

[Veronis]

Sorry I should have been clear - I don't think there's a problem at all.

I was placed under the impression by other threads I've read in the past that once fermentation is more or less "finished", moving it to a slightly warmer spot for a week or two will make the yeast ferment a bit more, resulting in slightly lower FG.

Correct me if I'm wrong. I'm happy to leave it in the swamp cooler all month (eventually the swamp will rest at around 68 with no intervention); I just thought I was supposed to move it to room temp (~71 ambient) at some point and let it sit a bit longer.

 

[gr8shandini]

It sounds like you're thinking of a diacetyl rest for a lager. You usually want to do that when it's about 75% of the way to FG. However, unless you have a very big beer or are using a very flocculant yeast strain, you don't have to worry about an ale.

But since you're actively managing your swamp cooler, I'd say it's safe to stop after 3 or 4 days.

 

[Veronis]

Understood. Thanks

 

[fuzzy2133]

It sounds like you're thinking of a diacetyl rest for a lager. You usually want to do that when it's about 75% of the way to FG. However, unless you have a very big beer or are using a very flocculant yeast strain, you don't have to worry about an ale.

But since you're actively managing your swamp cooler, I'd say it's safe to stop after 3 or 4 days.

Yes depending on how big of a wort you made.

Sorry I should have been clear - I don't think there's a problem at all.

I was placed under the impression by other threads I've read in the past that once fermentation is more or less "finished", moving it to a slightly warmer spot for a week or two will make the yeast ferment a bit more, resulting in slightly lower FG.

Correct me if I'm wrong. I'm happy to leave it in the swamp cooler all month (eventually the swamp will rest at around 68 with no intervention); I just thought I was supposed to move it to room temp (~71 ambient) at some point and let it sit a bit longer.

My understanding is that once active fermentation is finished (krusen dropped) the yeast (Ales) are less likely to create off flavors in a warmer environment. Warmer temps keep the yeast from going dormant too soon and encourages them to clean up any by-products that were produced (like the green apple taste). Yes you might get a slightly lower FG.

I have done this on my last 2 brews 1-2 days after the krusen has fallen with no ill effect.