How low can I go with my lagering temperature?

[ocwo92]

My previous lagers have been limited to the ambient temperature in my garage in the winter. Now I've constructed a better temperature control and I'm just about to ramp down the temperature of my most recent lager to lagering temperature.

Since beer contains alcohol, I assume it's safe to drop slightly below the freezing point of water, but what's the lower temperature bound before beer with a typical alcohol content begins to freeze? Does it make sense to go that low at all?

 

[didinho]

there is an empiric rule that says 1 Celsius degree below zero per each alcohol point.
So, a 4% beer should start freeze at -4C

 

[ocwo92]

Now you mention it, I recall having heard that rule before. Thanks for refreshing my memory.

Would it make sense, beer-wise, to lager at such low temperatures?

 

[stratslinger]

If I recall, the colder you can get it, the less time you need to spend lagering. So, if you can conveniently reach those kind of temps without freezing, I'd say it makes sense.

 

[didinho]

Would it make sense, beer-wise, to lager at such low temperatures?

in the first part of lagering, yeast is still active and still consuming sugars. maybe you can leave some time a couple of degrees above zero to ensure this process, then go below zero for the finishin lagering part

 

[ocwo92]

in the first part of lagering, yeast is still active and still consuming sugars. maybe you can leave some time a couple of degrees above zero to ensure this process, then go below zero for the finishin lagering part

There are those who believe that the temperature should be ramped down somewhat slowly just because of this. But that issue aside, I'm just curious about the final lagering temperature.

 

[DurtyChemist]

Other people believe you should slowly lower the temperature so you don't suck the liquid from your air lock/blow off into your beer.

 

[ocwo92]

Good point! (Although, if the fermenter is resonably air-tight, even a slow temperature change might eventually cause the airlock to suck air from the outside if the beer and air volume in the carboy drops because of the temperature.)

In my case, that's not a problem because my fermenter doesn't leave room for an airlock, so I have to do with a piece of plastic and a rubber band.