First lager under pressure - advice needed

[RGeats]

Hi all.

I have done a couple of fermentations in my snubnose fermenter so far, but each I have fermentation open and then pressurised at the end of fermentation.

The next brew I'd like to do is a simple lager, and I'd like to hear from others who have brewed one under pressure.

I'm planning on using W 34/70, and assume I pitch 2 packets.

Questions I have are around when to pressurise, what pressure to use, what temperature profile and what length.

I've got ideas but would like to hear others thoughts.

Thanks

 

[Saisonator]

Hi all.

I have done a couple of fermentations in my snubnose fermenter so far, but each I have fermentation open and then pressurised at the end of fermentation.

The next brew I'd like to do is a simple lager, and I'd like to hear from others who have brewed one under pressure.

I'm planning on using W 34/70, and assume I pitch 2 packets.

Questions I have are around when to pressurise, what pressure to use, what temperature profile and what length.

I've got ideas but would like to hear others thoughts.

Thanks

From my understanding, you set it to 15 psi right from the begining.

 

[MickDundee]

I’m definitely not an expert (I’ve done 2 pressure ferments) but both times I’ve let it pressure itself from its own fermentation. I’ve kept an eye on the pressure and set the spunding to 10PSI whilst fermentation is active then turned the valve up when krausen starts subsiding. When I cold crashed it reduced to 5PSI itself and was very nearly fully carbonated by kegging time.

 

[RGeats]

Thank you for your replies. Any advice on temperatures to use with this yeast under pressure?

 

[MickDundee]

Thank you for your replies. Any advice on temperatures to use with this yeast under pressure?

I’ve not been brave enough to test it so just stuck with my usual 11C then raise to 18C for diacytil rest.

 

[emerson909]

I ferment W34/70 at 21c under 15 psi from the start pitching 1 pack into 21 litres of 1.047 wort. It’s normally finished after 4 or 5 days. Done 5 or 6 batches like this now and consistently get a very clean fermentation, I can’t pick out any off flavours. I have been letting the pressure rise to 28 psi from about 1.017 to get 2.5 vols co2 then crashing to around 2 deg and dropping the pressure as it chills so it doesn’t absorb any more gas. I’ve got a batch crashing now and just going to leave the pressure alone and see what the carbonation ends up like.

 

[RGeats]

I ferment W34/70 at 21c under 15 psi from the start pitching 1 pack into 21 litres of 1.047 wort. It’s normally finished after 4 or 5 days. Done 5 or 6 batches like this now and consistently get a very clean fermentation, I can’t pick out any off flavours. I have been letting the pressure rise to 28 psi from about 1.017 to get 2.5 vols co2 then crashing to around 2 deg and dropping the pressure as it chills so it doesn’t absorb any more gas. I’ve got a batch crashing now and just going to leave the pressure alone and see what the carbonation ends up like.

Thank you from your clear reply and advice. So the pack for W34/70 says 11g to 11l, so 2 packs would be recommended for 21l. You are only using one, is that ok because it is fermenting at a higher temperature?
What temp do you pitch at? At the 21c or lower and then bring the temp up over time?

Thanks for taking the time to reply

 

[emerson909]

Yes from what I have read you can use ale pitching rates when fermenting lager yeasts at ale temp and it seems to work fine for w34/70, I do rehydrate before pitching. I pitch at 21 and keep it there until fermentation is finished.

 

[RGeats]

Ok thanks, one last question sorry! Do you use CO2 to raise pressure to 15psi straight away or do you let the yeast bring the pressure up?
Thanks

 

[emerson909]

No worries, I use co2, mainly to check fermenter is not leaking

 

[uDicko]

both times I’ve let it pressure itself from its own fermentation. I’ve kept an eye on the pressure and set the spunding to 10PSI whilst fermentation is active then turned the valve up when krausen starts subsiding.

Do this!

 

[RGeats]

Do this!

Any impact on temperatures doing it this way? Set about 20c from the start? Not sure how long it takes to get to 10 psi after start of fermentation, I wouldn't have thought long?

 

[uDicko]

Just ferment as normal. No impact on temperature. Obvs the lower the slower fermentation generally.

I always let it rise from start to allow best yeast growth then spund at 10-15psi for remaining.

15psi is reportedly supposed to be happy ground for ester reduction at ale temperatures and not hindering the yeast.

 

[brewchef]

The pressure reduce cell growth so let it build up naturally like last poster wrote