Dueling effects of ambient temp vs. yeast activity on wort temp

[McKnuckle]

So I brewed today, nice and cool out here in NJ. Got the wort chilled down to about 66F and sitting in its pail in my 50F garage. I'd like to ferment at about 63-65 ideally (using WLP001).

If I pitch yeast now, do you think the yeast will take off soon enough to counter the effect of the cooler ambient temp? Or is it just too cold, and the ambient will take over and drag the wort temp down below my target? It does take a while to cool down, just sitting there passively (currently a 16 degree differential).

Hope the question is clear. I've pitched just now in any case. I can easily move the pail to my chamber and stabilize it if necessary, so this is a "what do you think will happen" type of question. Thanks for any feedback.

 

[bd2xu]

You will probably have a lag in start time until it gets up around 60°, assuming the yeast is healthy etc. pitching to low won't hurt, but the yeast will probably go to sleep until it gets up to its active temp.



Primary: Maibock, Helles (first partigyle batch), Oatmeal Brown Ale
Secondary:
On tap: Orange Belgian IPA, Turbo IIPA, Mojave Red, Black Magic Stout
Bottled: Dwarven Gold Ale, La Fin Du Mond clone, Hefeweizen

 

[Qcbrew]

Well it does take a long time for 5 gallons to go from 66F to 50F (about 18-24 hours). That should be about the time needed for yeast to finish the lag phase and enter primary fermentation assuming you pitched enough healthy yeast.

However, here is the problem; even if it reaches primary fermentation (it might not if you didn't pitch enough yeast), the yeast can considerably slow down and even go dormant during fermentation. This leads to a few issues; 1.under-attenuated beer 2. funky off flavors due to temperature stress (yes cold can stress yeast as much as heat) 3. lack of scrubbing of gases and off flavors due to non vigorous fermentation (related to 2).

You should try to move your fermenter to a warmer place for the rest of your fermentation.

 

[jahdub]

Wrapping it in blankets might help keep the temperature up. Especially if you're only expecting it to get down to 50F..

 

[duboman]

I would place the vessel in a large bucket of water ot provide some insulation, think swamp cooler and the buffer it creates. You can also use an aquarium heater in the swamp cooler to maintain a proper temperature.

 

[McKnuckle]

Thanks for the replies. I wasn't thinking so much about how to keep the fermenter warm enough in the 50 degree room. I was curious about which temperature effect would "win the race" - would the chilly ambient room cool the wort down to a sub-optimal temp first? Or would the yeast begin working before that occurred, and raise the wort temperature with their active phase? Oh well. It's moot now, as the wort hit 63F so I moved it into my ferm chamber.