Fermenting under pressure

[lexuschris]

Hey all,

I know a few of you have started to ferment under pressure. I'd like to know more about the needed equipment to do this. What pieces and equipment are you using for fermenting under pressure? Any side issues to know about?

Thanks!
--LexusChris

[ctninh]

Fermenting under pressure is used by brewery pilot systems to get as close to the parameters of their production system. There are already equipment made to do that. I'll have to look things up if you want to get into it. Some research is out there if you look or have access.

In general, pressure causes more stress on yeast. That can mean more esters and other fermentation products. Also, yeast flocculates sooner and better under pressure. Since they are stressed, there's the inreased autolysis risk. There should be more technical considerations and I can look into it later.

The best thing you can do I s check if equipment have a pressure rating. If it should not be used under internal pressure, for your and everyone nearby's sake stop there.

-Calvin

[brahn]

I'm using a Sanke keg with the Brewer's Hardware Sanke kit, but got it customized to have a threaded connection for the blowoff tube and a TC connector on the racking cane so I can attach a ball valve.

I bought a spunding valve from Windsor and took it apart to connect to the threaded blowoff to manage the pressure. There are nicer pressure relief valves out there than the one I'm using. I think Jon and Tim both have the same one that's easier to dial in.

A couple gotchas to be aware of:

• You'll need a way to add co2 to the fermenter to push the beer out at racking time. I use a flare ball valve on a Y with the PRV. A ball lock port would be even easier.
• You'll want to maintain pressure in your keg as you're filling it to prevent foaming. I use a second spunding valve for this. You can do it by venting the PRV on the keg lid but the spunding valve makes it a lot easier.

In general, pressure causes more stress on yeast. That can mean more esters and other fermentation products.

One of the primary benefits of fermenting under pressure is lower ester production even at higher temperatures. Diacetyl production is increased, but it's also removed quicker by the yeast.

https://scottjanish.com/fermenting-dry- ... -pressure/
http://braukaiser.com/wiki/index.php/Fe ... f_the_beer

[JonW]

Below is a picture of my valve setup. I used a cross fitting to attach the spunding valve, gauge and corny post with a tri-clover fitting on the bottom. The corny post works well to vent the fermenter if you need to open it and also to recharge the Co2 if you're dry hopping, plus it makes it easy to push the beer to the keg like Brent mentioned.

I have not noticed any esters or off flavors - just the opposite. I think my beers flocculate and clear up quicker and are near ready to drink at kegging time. I usually let the beers ferment at just below 1 bar (~14 psi).

Fermenter.png (7.98 MiB) Viewed 9663 times

[CurtisG]

What do you ferment in right now Chris?

[lexuschris]

Well, currently I've gone back to plastic buckets. My sanke keg fermentor had issues getting clean, but I generally liked the concept. I just wish I could get a solid view and arm on the krausen buildup. Going back to buckets was an easy step, and I do enjoy splitting my batches in half, with different yeasts or hops. It makes the 10 gallon batch size more enjoyable.

However, I transfer via auto-siphon, and have had issues with oxidation. I am thinking of going back to keg transfers under pressure. That would either be back to a new sanke, or perhaps a stainless steel bucket (e.g. SSBrewTech, or other). Someday, it would be great to go jacketed conical, but I'm not quite ready for that one yet.

So, before getting any new gear, I was curious to what folks were using for their 'under pressure' fermentors. I'm not even sure if transfers under CO2 will work with those SS bucket lids. I know they have a gasket and lid clamps, but will it hold enough pressure for a transfer?

Loved the ideas and photos above! Thanks!
--LexusChris

[CurtisG]

Only reason I ask is to see if you could augment what you currently have to pressure ferment.

I had the same issues with my sanke fermenter, being that I never liked the idea that there was a ton of hidden stuff inside the keg i couldn't see.

I fermented in an SS brewbucket for awhile. I like buckets over carboys so the brewbucket was pretty great despite the weldless fittings. I tried modifying it with a corny post in the lid to add a spunding valve/ co2 in, but those lids
don't hold pressure at all. They sell a dome-style lid for them that do a better job at it, but I wouldn't go past 2-3 psi. Pretty sure Reid blew the lid off one of his once lol.

I also have one of our 8 gallon conicals, but with my fridge and garage setup I have to move it more than I like and it is heavy. A jacketed one would be better but I don't have the space for a permanent setup.

I ended up adding an 8" ferrule to my keg and putting one of our conical lids on it. The kegs hold well past 15 psi, but I only ferment around 6-8 psi to reduce oxidation. I'm not trying to carbonate during fermentation. It was perfect for 10 gallon batches. So much so that I found a 7.75G pony keg and made one for 5 gallon batches as well.

There is a pic of it on our instagram : https://www.instagram.com/p/Bm08GU_lu1o/

I have a TC thermowell in one port, a TC x corny post to add a spunding valve/co2 in and a 3" cap for dry hopping.

When I pressure transfer I remove the thermowell and I have a 1.5" tc x 3/8" compression fitting to use the same racking cane our sanke fermenters use. This way I'm able to do closed transfers into kegs.

[bwarbiany]

OT, but I never worry all that much about the inside of the Sanke. With a normal carboy scrub brush, with PBW and Mark II keg washer, and then with the ability to direct-fire the keg with water in it to sanitize, I figured it's not all that hard to get clean.

Hey Curtis (and by extension Derrin)... When is Brewer's Hardware going to start offering Brent's setup to the general public?

[CurtisG]

Hey Curtis (and by extension Derrin)... When is Brewer's Hardware going to start offering Brent's setup to the general public?

As soon as the general public stop threatening to blow themselves up

Without a proper PRV those caps have a bit too much liability in them to sell on the site.

We can make you one though! just promise you won't blow yourself up

[brahn]

We can make you one though! just promise you won't blow yourself up

I did have to promise this!

I suspect the o-rings/compression on the racking cane would give way before the keg exploded, but both could be catastrophic if you were in the wrong place.

[lexuschris]

Curtis,

Thanks for posting up the pic and description of your sanke keg conversion. That seems to hit most of my needs. I assume the 8" port makes for easy scrub down after fermentation. (My Coors sanke keg did not scrub down as easy as others have had... I've used a camera scope to view the buildup that is still in there.) However, I now have a Bud sanke, which looked really clean inside. Would love to look into putting the 8" ferrule and dome lid conversion on it. I think that would be a better option than doing the SSBrewTech bucket. I was worried it would not seal enough to hold much pressure, as you indicated.

If you could PM me some cost details, that would be great.

--LexusChris

[ScottK]

If you could PM me some cost details, that would be great.

Me too. I'm using the same setup.

[CurtisG]

I assume the 8" port makes for easy scrub down after fermentation.

Yep! Basically makes it as easy as cleaning out a bucket or kettle.

[bwarbiany]

When fermenting under pressure, how do you handle dry hopping and racking?

[CurtisG]

When fermenting under pressure, how do you handle dry hopping and racking?

I just vent the gas, dry hop and then hit it with some CO2. You can also make a pressure chamber to shoot hops in, I think Jonw has one so I'll let him post some pictures.

For racking, I just vent the gas, change my thermowell out to a racking cane, hook up the co2, and pressure transfer out.

With a conical it is a lot easier, just open up the racking arm and add Co2 to the top.