Carbonisation Calculations - Temperature

[MonsieurBadgerCheese]

Good Evening,

Sorry if this is a daft question. Relative Newbie here. Anyway, I have been experimenting with various 'Priming Sugar Calculators' I understand that temperature is a factor, but am a bit confused as to which temperature to apply.

For example The Malt Miller Calculator asks for 'fermentation temperature' wheareas Beersmith is asking for 'Bottling or Keg Storage Temperature. The Northern Brewer Calculator asks for 'Current Temperature of Beer'.

I'd appreciate any advice. For example, where do you stand if you have 'cold crashed' in the FV prior to priming in a bottling bucket/mini-keg?

Thanks in advance,

MBC

[Fil]

I would suggest the highest temperature the beer has sat in at the end of primary/ post primary should be used if its used to estimate the current level of dissolved co2 in the beer.

the reason is that as the yeast are the source of the co2 thats easily dissolved into the brew, so when they slow down and stop pumping it out the supply of possible further carbonation is thru contact at atmospheric pressure on the surface alone which will have a far less significant effect than co2 injected at the microscopic level under the surface by yeast. and while you can get suck back thru an airlock when crash chilling i would suggest that has more to do with the volume of co2 inside the vessel contracting with a lower temp than being instantly disolved in the beer without some positive pressure to aid the process..



Edit By sat, i mean a period of at least 12-24hours so that the beer has had ample opportunity to reach an equilibrium remembering due to its thermal mass the beer can lag significantly behind the trend of ambient temp.

[MonsieurBadgerCheese]

Excellent Fil! Thanks very much for your solution and explaination.

I will follow your advice.

Cheers,

MBC

[Fil]

well its good for a starting point at least Of course if you find the batch over/under conditioned you can adjust accordingly for the next time.

And if intending to serve from the fridge at circa 4-5C even bitters can stand a bit of overconditioning to counter the low serving temp..

[Fil]

well its good for a starting point at least Of course if you find the batch over/under conditioned you can adjust accordingly for the next time.

And if intending to serve from the fridge at circa 4-5C even bitters can stand a bit of overconditioning to counter the low serving temp..

[MonsieurBadgerCheese]

I would suggest the highest temperature the beer has sat in at the end of primary/ post primary should be used if its used to estimate the current level of dissolved co2 in the beer.

the reason is that as the yeast are the source of the co2 thats easily dissolved into the brew, so when they slow down and stop pumping it out the supply of possible further carbonation is thru contact at atmospheric pressure on the surface alone which will have a far less significant effect than co2 injected at the microscopic level under the surface by yeast. and while you can get suck back thru an airlock when crash chilling i would suggest that has more to do with the volume of co2 inside the vessel contracting with a lower temp than being instantly disolved in the beer without some positive pressure to aid the process..



Edit By sat, i mean a period of at least 12-24hours so that the beer has had ample opportunity to reach an equilibrium remembering due to its thermal mass the beer can lag significantly behind the trend of ambient temp.

So if the fermentation was constant at say 18C all the way through, and then cold crashed at 2C for 24 hours, I would base the calculation on 18C?

[jaroporter]

this question comes up all the time and always seems to divide opinions as realistically it's hard to calculate. i'd just pick one way of doing it and stick to that method each time, like fil says adjusting for next time depending on if you want more or less..

[Fil]

I would suggest the highest temperature the beer has sat in at the end of primary/ post primary should be used if its used to estimate the current level of dissolved co2 in the beer.

the reason is that as the yeast are the source of the co2 thats easily dissolved into the brew, so when they slow down and stop pumping it out the supply of possible further carbonation is thru contact at atmospheric pressure on the surface alone which will have a far less significant effect than co2 injected at the microscopic level under the surface by yeast. and while you can get suck back thru an airlock when crash chilling i would suggest that has more to do with the volume of co2 inside the vessel contracting with a lower temp than being instantly disolved in the beer without some positive pressure to aid the process..



Edit By sat, i mean a period of at least 12-24hours so that the beer has had ample opportunity to reach an equilibrium remembering due to its thermal mass the beer can lag significantly behind the trend of ambient temp.

So if the fermentation was constant at say 18C all the way through, and then cold crashed at 2C for 24 hours, I would base the calculation on 18C?

I would suggest so, but refine your priming if necessary based of results, serving conditions and your personal taste are two other important factors too.

[MonsieurBadgerCheese]

OK, thank you Fil.

MBC

[MTW]

I nearly always ended up with more carbonation than I wanted when I use the upper temperature, even over winter, when my bottles are stored in a very cold garage and I can be extra-sure that none of that extra fermentation is coming from excessively warm 'cellaring'. Yeast often finds new pathways in all but the very driest, coolest stored beers, so my advice is to go nearer the lower figure and work your way up in future brews, or at least somewhere in the middle, not assessing things too closely until a good few weeks later (unless you always drink it all within a month or something!).

A couple of stable days on a hydrometer does not mean that there will be totally zero action from that point onwards. I'm especially cautious in higher-finishing FG brews, even if the level of attenuation was expected. Trial and error, definitely, but I'd shoot lower and work up. I think everyone should probably try zero priming at least once too, in an appropriate style, just to see how much actually goes on after a supposed FG, though I've got to admit I haven't gone lower than 12g in 20L yet! Stout next, so maybe that's the one.

[MonsieurBadgerCheese]

Interesting stuff! Thanks for all of the feedback.

MBC

[HTH1975]

I always find that priming with 4-5g/L of dextrose works out fine. I store my bottles in the kitchen which can get cold as 15C in the winter and high as 25C in the summer. I’ve not noticed any difference. Leave the bottles for two weeks, chill in the fridge and you’re done.