What's the verdict on fermenting under pressure?

[Dgonza9]

I've been reading a lot about fermenting under pressure or using cornys without pressure but with a blowoff tube for primary fermentation.

Some claim cornys are great for this, others argue that the shape of cornys isn't suited to fermentation.

Anyone doing this that can speak to how well it works. I'm trying to decide how to up my fermentation space.

Thanks.

 

[Belmont]

I thought I saw a line in the last Zymurgy mag that made some comment about it but I don't remember exactly what was said. One thing that I do know for sure is that both fermenter size and shape will absolutely have an impact on the fermentation. Not necessarily bad or good but different. I think I heard something about the pressure on the yeast being different in a taller, skinnier fermenter than that of a shorter, wider one. Pressure has an effect on fermentation as well. The big breweries supposedly have more pressure in their fermenters and ferment at higher temps than we should as a result somehow. I heard Jamil Z saying that when the big brewers say they ferment at 72 in their fermenters he knows to back off that quite a bit because of the difference in fermenters. The Zymurgy article also said that as little a difference as covering a carboy with foil rather than an airlock can make a difference.

 

[samc]

I use a 15 gallon corny, but I have used 5 gallon ones in the past. They work excellently. I've done an inadvertent fermenting under pressure when the gas out poppet stopped the flow of CO2 coming out. I was surprised when I kegged my beer to find an almost fully carbed beer. It was a great beer, but I pretty much am too lazy to continue that practice as hooking up CO2 at the correct pressure is easier for me.

At the home brew volumes we do, I doubt you can find any real difference with your ferment based upon fermenter shapes.

 

[XXguy]

I knew WortMonger had done it & I thought I had bookmarked a sticky on this... but had to go find it:

https://www.homebrewtalk.com/f13/closed-system-pressurized-fermentation-technique-44344/#post435691

 

[dstar26t]

Hydrostatic pressure will have an effect on fermentation but we're talking about very tall tanks, not 2' tall cornies. If you want to ferment under pressure, you can raise the fermentation temp but too much pressure will cause problems (15+ psi). Some breweries seal the fermenter (and use a spunding valve to relieve excess pressure) at the end of fermentation to naturally carb the beer. The shape of a corny may be tall and skinny which decreases the surface area of the yeast sitting at the bottom but you can easily blast that yeast back into suspension by injection CO2 through the dip tube. Much easier than swirling a carboy.

 

[Belmont]

Awesome tip on blasting with CO2. Every time I go to swirl my carboy I think that there must be a better way and then forget about it. Kegs are at a premium in my brewery though so I don't have the luxury to ferment in kegs. I guess I need a stainless steel wand or something to stir inside the carboy.

 

[dstar26t]

I use stainless tubing to blast yeast or dry hops back into suspension from the bottom of carboys with CO2. Works like a charm and no worries about splashing and O2.

 

[Mateo]

I ferment in cornies, and only brew lagers. I do my primary fermentation in my freezer at 46-48F with a blow off tube. After about 40 to 50% attenuation, or 8 to 10 days I remove the blow off and move the kegs to inside the house. This is the time to harvest some slurry. I don't worry about the temp at this point and place a pressure release valve on the corny. I set it at 25 psi.

Once finished I simply remove the relief valve and move them to lagering at near freezing.

My beers come out crystal clear and super clean. When lagering is complete they are already carbed up to 2.3 volumes and ready to serve.

m

 

[lamarguy]

What's the verdict on fermenting under pressure?

It definitely doesn't suck...

 

[Dgonza9]

It definitely doesn't suck...

Hilarious. So basically this is how you do it:

1) Pump wort to corny.
2) pitch yeast and seal corny.
3) Attach beer out quick connect and use hose as blow off tube.
4) After vigorous fermentation is over, remove blow off assembly and attach spunding valve set at your carbing pressure.

5) Let beer condition. Maybe hit the dip-tube with some CO2 now and again to swirl up the yeasties.

6) When it's ready to drink, first pint or two will be yeast cake. The rest clear.

I assume you'd dry hop in bags. That pretty much it? If so, spunding valve here I come! I'd rather buy cornies than more better bottles.

 

[XXguy]

I think you want to go on the Gas post for your blow-off & spundling valve. You can harvest yeast off the beer out post.

Note Mateo's pic's up above, You'll see he's on the Grey (Gas) post.

 

[lamarguy]

Hilarious.

Thanks! I'm here all week.

As to your technique, you could pressure ferment the entire time (no blowoff hose), cold crash, and rack to serving kegs (adjustable racking arm).

 

[WortMonger]

I love doing this in Sankes and will be doing another lager tomorrow. Makes it very easy to just seal it up and set your release pressure, then just wait till its done. I have kept the same fermenter from the first batch under the little bit of pressure after emptying it. Now I just release the pressure tomorrow and refill it. I think I will harvest the yeast after this next time. Give it a try and see how you like it. The parts aren't that expensive to give it a go.

 

[Dgonza9]

Thanks! I'm here all week.

As to your technique, you could pressure ferment the entire time (no blowoff hose), cold crash, and rack to serving kegs (adjustable racking arm).

So just pitch your yeast and attach spunding valve at serving pressure?

Sorry, I have a few more questions before I start doing this.

Why rack to another keg? I thought you could just cold crash and then draw off the yeast and trub.

Does moving carbonated beer create issues?

I was planning on just making a transfer tube with corny quick connects on both ends for transferring. Will this work? I would pull off the yeast and trub first with a tap.

Can't wait to try this. It's on!

 

[Mateo]

You will not draw off much yeast or trub. It will settle and a small divot will form around the out tube. The rest of the yeast and trub will remain on the bottom. If you even touch the keg it will kick up. This is why its a good reason to transfer to a clean keg.

I use two black outs to transfer between kegs. I never open my kegs once pitched. The only air contact is when it hits the glass.

You must equalize the kegs before starting the transfer. Then set your pressure for 1 to 2 psi on the tank and release a little from your receiving keg. After a little bit it should be crystal clean going thru the tube.

Once you see some turbid beer passing quickly disconnect.

Do not touch the bright tank for 48 hours prior to the transfer and do not touch it when transferring.

Transfer as cold as you can to avoid any issues with foaming.

m.

 

[Dgonza9]

I think I found a parts list from Mcmaster.com

Here's the link for anyone else who needs it.

 

[daugenet]

I've been reading a lot about fermenting under pressure or using cornys without pressure but with a blowoff tube for primary fermentation.

Some claim cornys are great for this, others argue that the shape of cornys isn't suited to fermentation.

Anyone doing this that can speak to how well it works. I'm trying to decide how to up my fermentation space.

Thanks.

People try to translate everything from the large breweries to a small scale and the truth is that not all things are equal. You can ferment in a corny just fine. I would doubt that anyone could tell the difference between the beers and if they could it would be very slight. (as in they wouldnt notice if they didnt know to look for one)

For a while people worried about HSA too but on the small scale we work with it is not a huge concern. Could it happen? Sure. Likely? No.