Question about cold crashing and bottling

[jtrentpearson]

I've recently started to cold crash my beers but noticed that the amount of priming sugar changes significantly when you go to bottle at lower temps.

If i cold crash for a few days and then turn the temp on my fermenting chamber up to 70 for a day to get ready for bottling will that affect the clarity that i was trying to achieve with the cold crashing? I just don't want to over/under carbonate my beer. Thanks.

 

[Pappers_]

I cold crash and haven't noticed any difference in the amount of priming solution needed (when I bottle). Are you letting the bottles warm up (after bottling) to room temperature to bottle condition?

To answer your question, I don't think that letting the temp of your fridge rise up to 70 after cold crashing would have any negative affect on clarity. The stuff that's dropped out of your beer should stay dropped out, unless you shake it up.

 

[jtrentpearson]

I cold crash and haven't noticed any difference in the amount of priming solution needed (when I bottle). Are you letting the bottles warm up (after bottling) to room temperature to bottle condition?

To answer your question, I don't think that letting the temp of your fridge rise up to 70 after cold crashing would have any negative affect on clarity. The stuff that's dropped out of your beer should stay dropped out, unless you shake it up.

Yes, they bottle condition at about 70. I just bottled my first cold crashed beer and noticed that when trying to calculate the priming sugar needed that it was much lower when the beer was at 40 than it was at 70.

just curious if people compensate priming sugar due to temp or adjust temp in order to bottle.

 

[Pappers_]

I see your point. The calculator takes into account the amount of CO2 already dissolved into the beer, which varies by temperature. I misunderstood your question.

 

[doug293cz]

Yes, they bottle condition at about 70. I just bottled my first cold crashed beer and noticed that when trying to calculate the priming sugar needed that it was much lower when the beer was at 40 than it was at 70.

just curious if people compensate priming sugar due to temp or adjust temp in order to bottle.

You should input the highest temp the beer has reached post fermentation into the priming calculator. The temp is used to estimate how much CO2 is left in the beer from fermentation. If you end fermentation with 0.8 volumes of CO2 (a typical value), and want 2.5 volumes of carb, then you add priming sugar to create 1.7 more volumes. No new CO2 is created in the beer during cold crashing, and the amount absorbed from the headspace is minimal (I did a full analysis here. Don't go there if you don't like math.)

Brew on

 

[Mothman]

I'm new to homebrewing, but I understood that you should use the highest temperature achieved during active fermentation when using priming calculators...

As I understand it, that is because while colder beer can hold more dissolved CO2, thus requiring less priming sugar, at the time you are cold crashing the yeast is no longer actively creating much CO2, so the lower temperature at that time is mostly irrelevant. The CO2 that will be already present in the fermented beer was generated when the temperature was higher. During cold crashing, some CO2 from the headspace may re-dissolve into the beer... but not a lot???

Maybe?

More experienced brewers can shed more wisdom.

EDIT--- yeah, listen to doug293cz

 

[doug293cz]

I'm new to homebrewing, but I understood that you should use the highest temperature achieved during active fermentation when using priming calculators...

As I understand it, that is because while colder beer can hold more dissolved CO2, thus requiring less priming sugar, at the time you are cold crashing the yeast is no longer actively creating much CO2, so the lower temperature at that time is mostly irrelevant. The CO2 that will be already present in the fermented beer was generated when the temperature was higher. During cold crashing, some CO2 from the headspace may re-dissolve into the beer... but not a lot???

Maybe?

More experienced brewers can shed more wisdom.

EDIT--- yeah, listen to doug293cz

You still get points for having all correct information in your post.

Brew on

 

[jtrentpearson]

Thanks for the info.

Just to be clear. If I have a beer that is suppose to ferment at 50ish but for the first couple days sat in my 60 degree basement because of lack of space in my fermenting chamber then I would calculate the priming sugar based on 60 degrees?

 

[Mothman]

You still get points for having all correct information in your post.

Brew on

I was close... but I actually thought highest temp DURING fermentation was the key, didn't realize the highest temp post-fermentation should be used.

 

[doug293cz]

Thanks for the info.

Just to be clear. If I have a beer that is suppose to ferment at 50ish but for the first couple days sat in my 60 degree basement because of lack of space in my fermenting chamber then I would calculate the priming sugar based on 60 degrees?

No, highest temp after fermentation has stopped. If you start high and then cool, but fermentation is still going on, then CO2 is still being generated in the beer. CO2 keeps coming out of the beer until the carb level in the beer is in equilibrium with the CO2 in the headspace. After fermentation has gone on for a few hours, the headspace is ~100% CO2, so the CO2 partial pressure is 14.7 psi absolute (psia) or 0 psi (gauge). So the residual carb level in the beer is whatever the carb chart, or calculator, says for 0 psi at the temp when the fermentation finishes. If you raise the temp after that, more CO2 comes out of the beer, but if you lower the temp, very little additional CO2 goes into the beer.

Brew on

 

[Mothman]

Piggybacking on this thread, how 'picky' should a person be?

eg. if a beer is sitting at, say, 60 for most of it's primary, but was to move up to say 70 for a day, then go back down to 65 for the remainder of primary until bottling.... you would still use 70F?

 

[doug293cz]

Piggybacking on this thread, how 'picky' should a person be?

eg. if a beer is sitting at, say, 60 for most of it's primary, but was to move up to say 70 for a day, then go back down to 65 for the remainder of primary until bottling.... you would still use 70F?

According to the BrewersFriend priming calculator, you need 4.3 oz of table sugar to prime 5 gal of beer @ 65°F, and 4.4 oz for beer at 70°F. That's a difference of 0.1 / 4.4 = 2.3%. How much calculus do you want to do to get closer than that?

I'm not kidding. The question you ask gets into integrating adsorption & desorption rates, which is gonna take some advanced math, if you want a really precise answer.

Brew on

 

[Mothman]

Hahahaha. Wasn't really looking for math. More wondering how much time (generally) at a particular higher temperature makes a difference? How quickly does CO2 come out of solution?

 

[doug293cz]

Hahahaha. Wasn't really looking for math. More wondering how much time (generally) at a particular higher temperature makes a difference? How quickly does CO2 come out of solution?

Rate questions are difficult to answer, and I'm not sure anyone around here can provide an authoritative answer. All I can say is that a glass of beer goes flat in a matter of hours (it's still got some carbonation even after it tastes flat.) But, as my last post shows, the difference is insignificant for small temp changes. So why worry about it?

Brew on

 

[Mothman]

Fair enough The question came to mind as my currently-fermenting beer (I asked about this in another thread) jumped up to about 77F while I was out of town. May have been there for a day, I'm not sure how long exactly. Normally it would have remained around 65-70. I thought that was significant.

However, playing with a priming calculator, even that difference (say 68-77F) seems to only make a difference equivalent to 0.1 volumes CO2... so as you say, why worry.