Beer temp & priming...

Please help me know how to answer this priming calculator - it wants to know the temp of the beer.

My porter's first two weeks of fermentation were 65-67F. Then, after FG stabilized, I put it in the basement where it is ~57F. It will have been there for a week by the time I bottle it this weekend, and then I plan to let it carb for 2 weeks at 65-67F.

So what should I enter when it asks "temperature of beer"? Obviously I don't want it under-carbed or over-carbed, I want it just-right-carbed

Thanks for your help!

I just discovered the "Please delete" thread -on page 57- and that is some hilarious, time-wasting stuff!

Enter prime temp as the temp that it was fermenting at.

You'll be returning to room temp to carb, so this is the best bet.

I think I read somewhere that it means the highest temp your beer reached after fermentation stopped. The calculators are trying to estimate the residual CO2 left in your beer, which is a function of temperature, before telling you how much sugar to add to get the desired final volumes of CO2

Not *all* of the CO2 is coming from the yeast eating the priming sugar, there's some CO2 still in solution from the earlier active fermentation. The amount still in solution will depend on temperature.

I don't (can't) cold crash, so I bring my fermenter up out of my basement and set it on the counter. I give it 20 minutes or so for any disturbed yeast to settle back down before bottling, then check the temp on the stick-on fermometer. That's the temp I put in the priming calculator.

So for instance if you raise the temp to 70F for a Diacetyl rest after fermentation has stopped, and then cold crash at 35F before bottling, you'd want to use 70F in the priming calculator not 35F, since the higher temp will drive off some residual CO2.

In your case, looks like you had it at 65-67F after fermentation was done, then moved it to 57F. You should use 67F as your temp.

Thanks @Psylocide and @jtratcliff!

Dunno if you have already bottled or not, but, the current (May-June) issue of BYO has an article on calculating amount of priming sugar. The formula on page 78 describes temp as "temperature of the beer at bottling in degrees Fahrenheit".

Not sure if the article is up on the web or not, but I found it a good read.

HTH,

Ben

bloyall said:

The formula on page 78 describes temp as "temperature of the beer at bottling in degrees Fahrenheit".

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Hmm... Interesting. I was thinking of bottling in my ~57F basement in order to avoid disturbing the yeast, and then taking the bottles upstairs to my ~67 closet to carb up. Psylo and JT had me thinking I'd use 67F as my temp, as the reasoning about residual CO2 makes sense.

jtratcliff said:

the higher temp will drive off some residual CO2.

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Maybe I'll bring the carboy up to the kitchen in the morning, let it settle down and warm up, and then bottle after work. That way I'll be following everyone's advice! Thanks for pointing out that article @bloyall

You can bottle in your basement, just use 67 as your temp for calculating priming sugar. No need to bring it up. Any CO2 driven off at 67F won't reappear at 57F

Michael_K said:

Hmm... Interesting. I was thinking of bottling in my ~57F basement in order to avoid disturbing the yeast, and then taking the bottles upstairs to my ~67 closet to carb up. Psylo and JT had me thinking I'd use 67F as my temp, as the reasoning about residual CO2 makes sense.



Maybe I'll bring the carboy up to the kitchen in the morning, let it settle down and warm up, and then bottle after work. That way I'll be following everyone's advice! Thanks for pointing out that article @bloyall

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Yes, you can bottle in the basement, and use the highest temperature the beer reached during fermentation to determine the amount of priming sugar.

I have to admit that I often say that I HATE those priming calculators, because they will often have you carb "to style", and that can mean flat beer (say, a stout at 1.5 volumes, which is totally flat) or bottle bombs (a weizen at 4+ volumes). Sure, it's true that some styles are noted to be more highly carbed on tap, but when consumers in the US buy a bottled beer, there is a pretty standard level of carbonation.

I use .75 ounces of corn sugar (by weight) per finished gallon for lower carbed beers, and 1 ounce per finished gallon for my higher carbed styles. I haven't had a bottle bomb, ever, and I've never had a flat beer. So that is a pretty good rule of thumb if you doubt a priming calculator.

Just to follow up to my post about the BYO article previously:

There is a lot of discussion on this topic in the science forum.

In reading that discussion in contrast to my quoted BYO article, I have to say I disagree with BYO. I would use the the temp of fermentation.

To me the logic is simple: if you ferment at 68F your beer will have developed the CO2 residual that 68F beer can hold. If you cold crash that 68F beer, it will have the capacity for higher residual CO2 due to the lower temp, BUT, it will not generate any more CO2 because the cold crash has stopped most fermentation. By the same token, it will not have lost any CO2 that it had at 68F because the cooler temp increases the capacity of CO2 the beer can hold. Therefore there is no force pushing the CO2 out at the cooler temp.

When I bottle the ESB I currently have crashing, I will be basing the priming sugar amount on 68F not 35F.

Sorry if I muddied things earlier.

Ben

jtratcliff said:

Any CO2 driven off at 67F won't reappear at 57F

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This makes sense. Thanks JT!

yooper said:

I use .75 ounces of corn sugar (by weight) per finished gallon for lower carbed beers, and 1 ounce per finished gallon for my higher carbed styles. I haven't had a bottle bomb, ever, and I've never had a flat beer. So that is a pretty good rule of thumb if you doubt a priming calculator.

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This!! Thank you Yooper! Goodbye priming calculators...

bloyall said:

Sorry if I muddied things earlier.

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No worries Ben! This topic has been muddy water to me, so to speak, until this thread. And I like BYO too, but when in doubt, I cross-reference with HBT!

Thanks everyone!