First Cold-Crash... Need Input

[MikeBergan]

ok, so I am trying cold,crash on a 2.5 gallon batch, for the first time. I plan to crash for about 1-2 days at 34-36 degrees. Fermentation temp was about 65-67.
What do I use for calculating priming sugar addition to bottling bucket?

Web-tools show anything from 1.0 to 2.2 ounces of priming sugar for the batch...depending on which temp I use.
I do want to batch prime, but want to make sure I get it right, not bottle bombs, and not undercarbed mess.

What is the right way to sort this?

 

[zam216]

It depends on the program your using to calculate your carb level. The reason the calculators ask for the temperature is to calculate residual CO2 in the liquid and find out how much more you need from your sugars. Most want you to use the temperature you fermented at because assuming you cold crashed at the end of primary when all yeast activity is limited or finished the amount of CO2 should be the same because colder temps hold CO2 better. If you use the chart on http://byo.com/resources/carbonation it gives a good explanation of the CO2 levels and priming with different sugars.

 

[Scut_Monkey]

I would let it come back up to room temp for a couple days 60-68F. This will make your calculation much easier but more importantly the yeast that will be using the priming sugar will be able to carbonate in a reasonable time. Once it is in the bottles you are to leave it at room temp to allow it to carbonate anyways.

 

[MikeBergan]

Thanks guys... I guess I'll 'crash' it for a day or two, then pul it out and let it sit for at least a day at room (72'ish) temps? them bottle and age at same for a week-two weeks?

oh, FYI, this is a dark amber/black ale hopefully with a bit IPA type hoppiness. We'll se I guess

 

[Scut_Monkey]

I calculate 1.5 oz of dextrose is needed to get you in the middle of the carb range for an IPA. This is from Tastybrew.com. This is if you have a 2.5 gallon batch and bottle it at 72F. Don't worry about bring the beer back up to temp in regards to your cold crash. It will still have served its purpose to expedite yeast floccuation.

 

[MikeBergan]

Batch may end up just under 2.5 gallons... not sure exactly what the trub/yeastcake will account for, but that is a good number Scut_Monkey. Right in the middle if the various projections. 14 days of fermentation at 64-66 Fahrenheit plus about 2 days 'cold-crash' at '35 F', I'll let the batch warm a bit while prepping to bottle, but it will probly be about 70.

 

[myelo]

Use the highest temperature your beer was at AFTER fermentation was finished.

The basic idea is the maximum mount of CO2 that will remain in a liquid is dependent on temperature -- the higher the temperature, the less CO2 you can dissolve in a liquid.

After fermentation, your beer has a certain amount of CO2 due to fermentation. Beyond that, if your beer gets warmer, it will lose some C02. But if it gets cooler it won't gain more CO2 since there's no source of CO2 (fermentation is done).

So the maximum temperature after fermentation dictates the amount of C02 in your beer at the time you add the priming sugar.

 

[MikeBergan]

Use the highest temperature your beer was at AFTER fermentation was finished.

The basic idea is the maximum mount of CO2 that will remain in a liquid is dependent on temperature -- the higher the temperature, the less CO2 you can dissolve in a liquid.

After fermentation, your beer has a certain amount of CO2 due to fermentation. Beyond that, if your beer gets warmer, it will lose some C02. But if it gets cooler it won't gain more CO2 since there's no source of CO2 (fermentation is done).

So the maximum temperature after fermentation dictates the amount of C02 in your beer at the time you add the priming sugar.

ok, so, I cold-crashed for about 36-40 hours, and then had to pull it out due to temp issues... brew has been sitting at approx 70 for about 2 days. so I should batch prime using 70 as the temp?

 

[C-Rider]

I've bottled after as much as a week of cold crashing. I bottle cold and use what ever amt BeerSmith says. Never had a problem after 3 weeks at 70.

 

[myelo]

ok, so, I cold-crashed for about 36-40 hours, and then had to pull it out due to temp issues... brew has been sitting at approx 70 for about 2 days. so I should batch prime using 70 as the temp?

Yes, assuming it didn't get higher than 70 before you cold crashed.

 

[kombat]

myelo is exactly right. Use the highest temperature it reached AFTER fermentation finished.

Also, I would NOT let it warm back up after cold crashing, before bottling. In my experience, if I allow a beer to warm up after it's been cold-crashed, I get little CO2 "geysers" popping up out of the yeast cake (due to a small amount of CO2 that was produced as the beer was cooling, and stayed in solution, but is now coming out of solution as the beer warms) and re-clouding the beer, undoing all the work done by cold crashing it in the first place.

Bottle it cold.