Priming sugar after cold crashing

[Blinky]

I need some help! I brew around 20 degrees, I cold crash to 3 degrees for 2 days, what temp do I put in the online priming sugar calculators?
I think it should be the temperature the beer was brewed at but the instructions say its the coldest temp the beer has been at. My thinking for ignoring this is that when the beer chills, it is not under any great pressure since the CO2 has bubbled out of the FV. Does anybody not agree with this?

 

[DoctorMick]

Use the fermenting temp, so 20c. :thumb: There is conflicting information on it but fermenting temp has always worked for me. Brewers Friend says this (which doesn't really help!):

* Temperature of Beer used for computing dissolved CO2:
The beer you are about to package already contains some CO2 since it is a naturally occurring byproduct of fermentation. The amount is temperature dependent. The temperature to enter is usually the fermentation temperature of the beer, but might also be the current temperature of the beer. If the fermentation temperature and the current beer temperature are the same life is simple.

However, if the beer was cold crashed, or put through a diacetyl rest, or the temperature changed for some other reason... you will need to use your judgment to decide which temperature is most representative. During cold crashing, some of the CO2 in the head space will go back into the beer. If you cold crashed for a very long time this may represent a significant increase in dissolved CO2. There is a lot of online debate about this and the internet is thin on concrete answers backed by research. We are open to improving the calculator so please let us know of any sources that clarify this point.

 

[Blinky]

Yeah that's what confused me,bf seemed to be indicating that I use the cold crash temp. I also had a couple of beers that were over carbonated and was leading me to think that I should use the cold crash temp to reduce the amount off priming sugar but I now think the problem was that I was bottling less that I though I was hence adding too much priming sugar. Will use fermenting temp from now on and see how it goes.