Pressure fermentation question

[SonomaBrewer]

Pieces of this topic in other threads but I can't find in one place.

If one takes higher temp and shorter fermentations off of the table, what are the upsides and downsides of fermenting under pressure at traditional lager and ale yeast temps?

 

[Rippchen]

Advantages:
-Carbonated beer at the end of fermentation
-less time of lagering till it is ready to drink

Disadvantages:
- more complex / expensive
- need CO2 to serve or transfer

 

[McMullan]

I've done a few pressure fermented lagers at usual lager fermentation temperatures (10-12°C). I think I prefer them, tbh. Crisper, imo. Nor did I notice any slowing down of fermentation rate. I repitch freshly harvested yeast and leave the FV 'open' for 12-24h, before adding a spunding valve set to about 15psi. Then increase the spunding pressure to 25-30psi after a few days to get a higher carbonation level. Ready for cold crashing and some lagering after about 7 days. It still reduces time going from grain to glass and conditions the beer for free at a convenient stage. I suspect the pressure helps promote flocculation. Ales, on the other hand, get really bland when fermented under pressure at usual ale fermentation temperatures. I haven't tried fermenting ales at elevated temperatures under pressure. Ales, imo, are best fermented 'open' with a spunding valve fitted towards the end of fermentation, to naturally condition/carbonate.

 

[Red over White]

Here's what I found out in the last few years of pressure fermenting. Pitch rate, temperature and pressure are intertwined and as you adjust one it affects the others. For example, if you apply 15+ psi immediately after pitch, you will reduce yeast growth at any fermenting temperature.

Pressure fermented lagers can be turned around quickly with very low esters and fusels, have a wonderful unmistakable mouthfeel and they mature very, very fast, because they are so very clean from the start.

For dry lager yeast here's what I have tracked with a tilt in over 70 ten gallon batches in the first 24 hours when pitched into 57-60°F 1.046 wort and no pressure applied with 20L of wort in each 30L fermenter.

1 pack sprinkled directly into fermenter:
1-3 point drop

1 pack in a 500ml vitality starter occasionally swirled made 4 hours prior to pitch:
6-8 point drop

1 pack in a 500ml vitality starter occasionally swirled made 4 hours prior to pitch with 5g goferm protect evolution:
10-12 point drop
This is my preferred method for growth and turnaround time

The headspace in the fermenter will determine how fast pressure will rise and thus determine growth for me in 30L all rounders. Naturally allowing pressure to build to 10 psi and then at high kräusen ramping to 25-28 psi is the schedule I have settled on. Temperature of the ferment can rise into the mid 60's after high kräusen with no difference in flavor of the finished product. I can confidently close xfer to a keg at day 5 fully carbonated. At day 14 its very, very good and at day 21 it's crystal clear and in peak condition (certain ale yeasts are perfectly ready in 7-8 days with this schedule).

Since I split the difference between lager and ale temperature I have kinda cherry picked the best of each with no downside in moderate strength beers. Hopefully, some of this helps those looking into this method.

 

[SanPancho]

Here's what I found out in the last few years of pressure fermenting. Pitch rate, temperature and pressure are intertwined and as you adjust one it affects the others. For example, if you apply 15+ psi immediately after pitch, you will reduce yeast growth at any fermenting temperature.

Pressure fermented lagers can be turned around quickly with very low esters and fusels, have a wonderful unmistakable mouthfeel and they mature very, very fast, because they are so very clean from the start.

For dry lager yeast here's what I have tracked with a tilt in over 70 ten gallon batches in the first 24 hours when pitched into 57-60°F 1.046 wort and no pressure applied with 20L of wort in each 30L fermenter.

1 pack sprinkled directly into fermenter:
1-3 point drop

1 pack in a 500ml vitality starter occasionally swirled made 4 hours prior to pitch:
6-8 point drop

1 pack in a 500ml vitality starter occasionally swirled made 4 hours prior to pitch with 5g goferm protect evolution:
10-12 point drop
This is my preferred method for growth and turnaround time

The headspace in the fermenter will determine how fast pressure will rise and thus determine growth for me in 30L all rounders. Naturally allowing pressure to build to 10 psi and then at high kräusen ramping to 25-28 psi is the schedule I have settled on. Temperature of the ferment can rise into the mid 60's after high kräusen with no difference in flavor of the finished product. I can confidently close xfer to a keg at day 5 fully carbonated. At day 14 its very, very good and at day 21 it's crystal clear and in peak condition (certain ale yeasts are perfectly ready in 7-8 days with this schedule).

Since I split the difference between lager and ale temperature I have kinda cherry picked the best of each with no downside in moderate strength beers. Hopefully, some of this helps those looking into this method.

Few Qs
- where would you peg your high krausen without visuals ( stainless conical), or where are you determining to bump back pressure up to 25+? using attenuation- 1/2, 60%, etc? some other criteria?
- what about dry hopping? no problems at warmer temps?
- are you clearing/fining at all ? Or just letting cold temp do the work?

 

[Red over White]

Few Qs
- where would you peg your high krausen without visuals ( stainless conical), or where are you determining to bump back pressure up to 25+? using attenuation- 1/2, 60%, etc? some other criteria?
- what about dry hopping? no problems at warmer temps?
- are you clearing/fining at all ? Or just letting cold temp do the work?

-Around 50% Attenuation

-I don't dry hop lagers or the few ales I brew, I whirlpool so I'm not much help here

-I use clarity ferm or clearzyme at pitch for chill haze and don't really need anything else

 

[stealthfixr]

Been pressure fermenting for a couple years with my Spike conicals. I've been impressed that most yeasts don't seem to be affected much at all. It can shorten the fermentation time at a higher temperature, with little to no penalty, depending on the style/yeast involved. Attenuation seems to be the same whether a fermentation is pressurized or not. Only beer that seemed to not like it was White Labs Bavarian Lager, but it still functioned with a spunding valve no problem in the last few points to FG after an unpressurized fermentation at 50F.

However, I have yet to see a 'cleaner' beer as a result of pressure fermentation. For example, a pressure fermented IPA with US-05 tastes the same at the same temp or higher than a non-pressure fermented version. And, I did find with a Saison once that pressure fermenting did seem to curb the normal Belgian yeast contributions, making for a dull Saison. For any beer with significant yeast derived contributions, I now ferment without pressure until I am a few points from FG, then on goes the spunding valve for every beer style.

If you are a low-oxygen fan, throwing on a spunding valve and pressure fermenting is a fantastic way to protect a finished beer from O2. I find that this is particularly helpful with any style that dry hops, especially like a NEIPA or Hazy IPA. A closed transfer to a purged keg from an O2-free conical is a night and day positive difference.

 

[YeastFeast]

If you are a low-oxygen fan, throwing on a spunding valve and pressure fermenting is a fantastic way to protect a finished beer from O2. I find that this is particularly helpful with any style that dry hops, especially like a NEIPA or Hazy IPA. A closed transfer to a purged keg from an O2-free conical is a night and day positive difference.

On a Hazy IPA, do you pressure ferment throughout the entire fermentation, and at what pressure? Thanks.

 

[stealthfixr]

I throw the spunding valve on from the very beginning, but it’s pretty wide-open or zero pressure for the first 24 hours until the yeast really gets going. Then I’ll slowly increase it overtime to five psi and let the majority the fermentation be there. Near the tail end, I’ll ramp it up to 10 psi, mainly because during the cold crash, it’ll drop about five psi. I like keeping a little positive pressure in the fermenter.