Priming sugar for cold crashed Pilsner

[Deon Botha]

Hi there fellow brewers. I'm about to bottle a Pilsner that has been cold crashed for 36 hours. Internet research suggest that I only use about half the sugar that I would have, if it was at its original fermenting temp. So now I am a bit sceptic on what to do? Any ideas? Thank you in advance

 

[Steveruch]

Cold crashing makes no difference in the amount of priming sugar.

 

[Jag75]

I may be wrong but it may struggle to fully carbonate after a cold crash by bottle priming. I've seen multiple people here have issues

 

[Robert65]

What Steve said is true.

What does make a difference however, is fermentation temperature, maybe that was what you saw reference to.

More CO2 can be dissolved in beer at lower temperatures. So the higher the fermentation temperature, the less CO2 the beer will already have at the end of fermentation, so you'll need more sugar to get to a given level of carbonation.

But cold crashing can't get CO2 back into beer that has already been driven out during a warmer fermentation. Consult a priming chart based on fermentation temperature, not the cold crash temperature.

 

[Deon Botha]

What Steve said is true.

What does make a difference however, is fermentation temperature, maybe that was what you saw reference to.

More CO2 can be dissolved in beer at lower temperatures. So the higher the fermentation temperature, the less CO2 the beer will already have at the end of fermentation, so you'll need more sugar to get to a given level of carbonation.

But cold crashing can't get CO2 back into beer that has already been driven out during a warmer fermentation. Consult a priming chart based on fermentation temperature, not the cold crash temperature.

I have been using online calculators like the one on brewersfriend. That is where I got the info from. But thank you for the advice

 

[rburrelli]

I have been using online calculators like the one on brewersfriend. That is where I got the info from. But thank you for the advice

Calculate your volume on the highest temp reached during fermentation per Roberts response.

 

[Deon Botha]

Calculate your volume on the highest temp reached during fermentation per Roberts response.

Thanks

 

[Lefou]

Cold crash, cold crash, cold crash ...
That used to stick in my brain early on as a new brewer, but you can reduce the possible need for a "cold crash" by using a few gimmicks. First off, if you have a reliable fermentation control unit (thermostat controlled refrigerator) and a thermometer, keep your temperatures stable toward the lower side of the yeast's temperature tolerance. Second, choose your yeast wisely. Some flocculate better than other and some stay in suspension extremely well making them excellent bottle conditioning yeasts. Some drop like a stone depending on temperature and their own peculiar characteristics.
Lastly, if you want to lager there's nothing stopping you from lagering IN THE BOTTLE OR KEG after your conditioning phase is finished.

 

[MikeCo]

As others said use the highest temp reached during primary or secondary in the calculator to get the correct amount of priming sugar. The beer should carbonate fine even with cold crashing, but you can add yeast at bottling of you want to make sure it carbonates in a reasonable time.

 

[Deon Botha]

Thank you all for the advice. So I have just primed as per the highest temp reached at fermentation

 

[doug293cz]

The advice to prime based on highest temp reached during fermentation is good. If you want to get geeky, and down and dirty with the math that proves this, go here.

Brew on

 

[jgodfrey]

I know this is a dated thread now, but I'd like a clarification on a slight twist to the typical cold-crash scenario. I always see the advice that the cold-crash won't impact CO2 because there's no source to replace the CO2 during the cold crash. However, in my scenario:

- I finish fermentation at, say, 68 F
- I cold crash to 34 F

However, my carboy is a plastic Fermonster that'll get crushed during a cold-crash. To prevent that, I connect a plastic bag full of CO2 to the carboy (via a tube in place of the airlock).

That causes the cooling beer to pull CO2 from the bag as needed instead of crushing the plastic fermenter.

So, I assume that additional CO2 is being absorbed by the cooling beer, right?

And, if that's the case, should I then use my beer's *current* temp (right after pulling from the cold-crash) for calculating priming sugar? Or, does my scenario not really change anything and the general "warmest post-fermentation temp" still apply?

As I've never been completely sure here, when I cold-crash, I generally let the beer warm back up to room temp before bottling, and use that temp for my priming sugar calculation.

Thanks for any clarity you can provide.

 

[jgodfrey]

Still seeking advice on my previous post (just above). Any input?

 

[AlexKay]

If you’re only letting CO2 in to the fermenter (there is no leaking air) then with a plastic bag containing an excess of CO2 you’ll end up with 1 atm of CO2 in your headspace — just the same condition as if you were fermenting at that low temperature. The open question is whether you have enough time to reach equilibrium; given that “set and forget” carbonation in a keg can take upwards of a week, I’m guessing not completely. You’d have a little more certainty if you leave it at cold crash temperature for a few extra days, while under CO2.

Can’t help more than this ... I carbonate in the keg. What do other people do?

 

[doug293cz]

I know this is a dated thread now, but I'd like a clarification on a slight twist to the typical cold-crash scenario. I always see the advice that the cold-crash won't impact CO2 because there's no source to replace the CO2 during the cold crash. However, in my scenario:

- I finish fermentation at, say, 68 F
- I cold crash to 34 F

However, my carboy is a plastic Fermonster that'll get crushed during a cold-crash. To prevent that, I connect a plastic bag full of CO2 to the carboy (via a tube in place of the airlock).

That causes the cooling beer to pull CO2 from the bag as needed instead of crushing the plastic fermenter.

So, I assume that additional CO2 is being absorbed by the cooling beer, right?

And, if that's the case, should I then use my beer's *current* temp (right after pulling from the cold-crash) for calculating priming sugar? Or, does my scenario not really change anything and the general "warmest post-fermentation temp" still apply?

As I've never been completely sure here, when I cold-crash, I generally let the beer warm back up to room temp before bottling, and use that temp for my priming sugar calculation.

Thanks for any clarity you can provide.

The problem is that the carb level will be changing on an hourly basis during cold crashing as CO2 gets absorbed from you balloon reservoir. If your balloon stores enough CO2 (it probably doesn't) you could cold crash for ~2 weeks and assume that you have come to equilibrium, so that your beer would be at the 0 psi cold crash temp equilibrium carb value.

The other possibility is to know the volume of CO2 in your balloon, wait for it to all be absorbed during cold crash, and then calculate the carb level increase that the volume in the balloon would create.

Brew on

 

[jgodfrey]

Thanks for the additional input @AlexKay and @doug293cz. So, no easy answers here I guess.

Related, I did have an issue recently where I cold-crashed a Festbier using the method I described above and let it come back to room temp after in an attempt to have a known level of C02 (also as described above). However, that beer ended up being over carbed by quite a bit. So, even that method failed me on one occasion (or, maybe I made a priming sugar measurement mistake that I wasn't aware of)...

I'd certainly like to continue cold-crashing certain styles, but I just haven't figured out a reliable method for calculating priming sugar after-the-fact, based on my equipment and situation (again, described above).