Lagering Question

[rinhaak]

I'm doing up a bock which I've been fermenting at 53°. I was initially planning on lagering it outside for two months. I live in Boston, so it seemed like that could be a great temp.

But then I started having second thoughts. Would the temperature fluctuation have negative effects on the beer? My feeling was that it would really take quite some time to shift the temperature of 5 gallons of beer, so that the outside changes shouldn't matter too much.

But today, I started to wonder if it dropped below freezing for too long if that would negatively effect my beer or even kill the yeast. How low of a temp can I safely lager?

I was considering wrapping the fermenter in a warm sleeping bag, just to help it not get too cold. Thoughts?

 

[helibrewer]

You can go slightly below freezing since the alcohol content depresses the freezing point a couple of degrees. You want to avoid flucuations, especially if the high side is above 40F

 

[rinhaak]

How much do you think is "slightly" below freezing? Boston rarely gets below 20° and almost never stays that cold for any long stretch of time. Would that be too far below freezing?

 

[osagedr]

I wouldn't let that beer get anywhere near 20 degrees. I freeze-distill my doppelbock at 19 to make Eisbock.

It's counterintuitive, but the desireable changes in your beer from lagering will take place at warmer, not cooler, temperatures. I had trouble wrapping my head around that but someone posted a link to what I considered to be convincing evidence of that a number of months ago. I am blessed with really excessive refrigeration space so tend to lager at 32 degrees. Right now I am absolutely swimming in beer so I am lagering recently brewed batches in my garage in the mid-to-high 40s. The higher temperature doesn't concern me in the slightest.

 

[helibrewer]

I wouldn't let that beer get anywhere near 20 degrees. I freeze-distill my doppelbock at 19 to make Eisbock.

It's counterintuitive, but the desireable changes in your beer from lagering will take place at warmer, not cooler, temperatures. I had trouble wrapping my head around that but someone posted a link to what I considered to be convincing evidence of that a number of months ago. I am blessed with really excessive refrigeration space so tend to lager at 32 degrees. Right now I am absolutely swimming in beer so I am lagering recently brewed batches in my garage in the mid-to-high 40s. The higher temperature doesn't concern me in the slightest.

I agree. I lager between 36-40F