# Lager Bottling Temperature?

Silly question. I will soon bottle my first lager (Boston lager clone). It has been lagering at 36 degrees for about 6 weeks now. Do I need to raise the temperature again before bottleing or can I just take the carboy right out of the fridge and bottle it cold?

You can bottle it cold, but it will still need to warm up eventually to carbonate. You want to carb your bottles at 70ish, same as with an ale.

If I were you, before you start I would let it warm up to the room temperature of the room you will be bottling in. That way you know for sure what temperature to use for determining how much priming sugar to use.

[quote=“Nate42”]If I were you, before you start I would let it warm up to the room temperature of the room you will be bottling in. That way you know for sure what temperature to use for determining how much priming sugar to use.[/quote]This is a common mistake when calculating priming sugar weight - you want to use the highest temperature that the beer achieved while actively fermenting, not the current temp of the beer. Doesn’t make a lot of difference if you aren’t cold-crashing or lagering first, but if do, and you use the cold temp instead, you’ll be over-estimating the CO2 in solution and end up under-priming the beer.

Thanks for the replies. Primary fermentation was around 55 degrees.

Did you raise the temp for a D-rest?

Yes I raised the temp for D rest before dropping down to lager temp.

Not entirely true shadetree, the issue is that CO2 is less soluble in higher temperatures. This is a true thing regardless of when fermentation stopped. The temp you want to use is the highest temperature it has ever been once fermentation started. For a lager, if you fermented at 50, and later let it sit at a room temperature of 70, then 70 is the temperature you want to use. Even though real fermentation is done, that excess CO2 that was dissolved at the lower temp is going to work its way out.

To further complicate things in the specific case of lagers, lager yeast is actually still (albeit slowly) active at lagering temperatures. Even though you’re no longer getting substantial attenuation, the yeast can still be active enough to produce a little more CO2. This is why I advocate warming up to room temp before bottling, that way any new CO2 escapes and you know for sure how much is in there. Or better yet, force carb in a keg and no longer worry about it.

Thanks for all the info. The boss (my wife) authorized me a keg and CO2 tank so I might just keg it in a week or so when the equipment arrives. Any thing I have to be careful of when doing that?

Not really. Read up on proper cleaning and maintenance of kegs, and how to keg carbonate. Make sure your serving lines are nice and long so you have a “balanced” system (you want your carbonation pressure to be equal to your serving pressure). One of the many nice things about keg carbonating is that it relies on the natural equilibrium of CO2 vapor pressure that happens at a particular temperature and carbonation level. How much CO2 is in solution right now is irrelevant, you just look up the appropriate pressure for your serving temperature, set it and forget it.

[quote=“Nate42”]The temp you want to use is the highest temperature it has ever been once fermentation started.[/quote] That’s what I meant but I wasn’t thinking about non-standard procedures like allowing a beer to sit at an elevated temp post-fermentation (but in that case, yes, use the higher temp).[quote=“Nate42”]This is why I advocate warming up to room temp before bottling, that way any new CO2 escapes and you know for sure how much is in there.[/quote]Sorry, was focusing on the concept of using the correct temp and not applying it to a lager specifically - assuming the bottling temp is higher than the d-rest temp, then it’ll work, but I would discount any CO2 production during lagering and rather have a slightly over-carbed beer (which can be fixed by letting the poured beer sit for a few minutes) than under-carbed (which can’t be fixed).

We agree on the process in general (account for CO2 in solution when using a calculator) but it’s clearly difficult to come up with simple, blanket statements about how to do it that cover all possibilities. And yeah, kegging makes dialing in a correct carbonation a whole lot simpler! :cheers:

I agree that you’d probably be okay, or perhaps very slightly overcarbed, with considering the D-rest temp as your bottling temp and go from there. I always liked letting it warm up before bottling because I’m anal, and that way you KNOW there is no extra CO2 in solution. I make no claims that my over-analysis is for everyone, or at all necessary.

:cheers:

I think the CO2 escapes rather slowly when you move a finished beer from cooler to warmer temps, especially if its only a modest jump. The CO2 gas will eventually make its way out but its not a matter of a few hours, it may well take a few days to reach that new lower level. But honestly if you’re off by a few tenths of a volume of CO2 is it something to worry about?

Now if you take a lager out of the 50F chamber, let it warm for a few hours and bottle thinking that beer is equilibrated, you are likely to have some gassy beer.

[quote=“tom sawyer”]I think the CO2 escapes rather slowly when you move a finished beer from cooler to warmer temps, especially if its only a modest jump. The CO2 gas will eventually make its way out but its not a matter of a few hours, it may well take a few days to reach that new lower level. But honestly if you’re off by a few tenths of a volume of CO2 is it something to worry about?

Now if you take a lager out of the 50F chamber, let it warm for a few hours and bottle thinking that beer is equilibrated, you are likely to have some gassy beer.[/quote]

Good points. I always gave it a day to stabilize and called it good. The extra time required for this is yet another reason why my anal methods are not for everyone, and why keg carbing is way easier.