Boil in Pressure Cooker

Has anyone performed their boiling part in a pressure cooker? What would be some advantages or disadvantages?


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Well, I can definitely think of at least a few disadvantages, not boiling off DMS, difficult to add hop additions.

General rule for using a pressure cooker is not to put anything in it that foams. Anything that foams can plug the vent causing a pressure increase. High pressure in pressure cooker equals a kaboom with metal and hot contents flying all over.

I pressure can wort for starters. You get one heck of a break.

I would think that if you kept the lid off it would be the same as any other pot.

Lid on just would not work, boil overs, plugged vents, difficulty with hop additions and other ingredients added to the boil, not boiling off DMS.

I have a large 23-quart pressure cooker that I use regularly for boils. I don't place the lid on it during the boil. But I do place the lid on it, just loosely, when I move the pot to cold-crash cooling. The lid is on to prevent potential sloshing out of the hot wort if I stumble, and I keep the lid on (loose) during cooling to prevent any accident crap from getting into the pot.

NO - no way do you want to attempt boiling with the lid on tight.

I've heard that newer pressure cookers have a lot of safety functions on them that ensure the cooker will not blow up. If that is the case would it work to boil the beer if you left lots of headspace and used an anti foaming agent?


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LandoAllen said:

I've heard that newer pressure cookers have a lot of safety functions on them that ensure the cooker will not blow up. If that is the case would it work to boil the beer if you left lots of headspace and used an anti foaming agent?

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I don't know about you, but I sure as hell would not risk my kitchen exploding because I wanted to try something new in the brew system.

What is the draw to a pressure cooker? I'm all for experimentation, but at some point it becomes messing with things just to mess with things.

I think the potential DMS problem alone would be enough to keep me away from using one, not to mention having to monkey with the lid for every hop addition and the prospect of hot wort and shards of metal flying through the air.

LandoAllen said:

I've heard that newer pressure cookers have a lot of safety functions on them that ensure the cooker will not blow up. If that is the case would it work to boil the beer if you left lots of headspace and used an anti foaming agent?


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The problem is not so much with boiling the beer, the pressure cooker will certainly do that. The problem is with some of the other issues already mentioned.

I agree that hop additions would be very difficult aside from the bittering hops. I was thinking about this in terms of speeding up the boil process since it can get much hotter than a normal boil. Since it gets much hotter it might have interesting effects on the bittering hops added before the lid goes on.

I also would never try this inside my house for obvious reasons. Lol


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The DMS is also still a potential problem if you're leaving the lid on the whole time.

Right. I get that. The lid would have to come off at some point to continue the boil for the DMS and the later hop additions.


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LandoAllen said:

Right. I get that. The lid would have to come off at some point to continue the boil for the DMS and the later hop additions.

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Dude, if you're just going to do it anyway, no matter what people say or suggest, why ask in the first place?

A medium pressure setting (8 to 10 psi) would get you to about 220*, A high pressure setting (15 psi) would get you to about 250*. Most pressure cookers cook at 15 psi, but some of the electric digital ones are at a lower setting.

Personally, I'd never do this. First off, you can't fill the cooker more than 2/3 full so unless you have a very large canning-type pressure cooker, I can't see where that would be advantageous. Secondly, you cannot add fat to the wort to keep it from foaming, as you would with say, a pot of beans or other foam-inducing ingredients. A defoaming agent MIGHT work but it also might NOT and that is not something I'd take a chance with.

Third, as pointed out multiple times, hop additions and boiling off DMS are gonna be a big problem.

Fourth, by the time you get it up to full pressure, cook it, and then cool it enough to open the lid, I don't think you're saving much, if any, time.

And fifth, yes, modern PCs have safety devices - but they are intended to blow out with pressures in excess of the temperatures at which the device is intended to cook, so you're STILL gonna make a big mess if one of the safety devices deploys.

So - why the heck would you chance it? It's an interesting "what if" but I'd not put it to the test, personally.

I have four pressure cookers - two of which are electric/digital, one a six quart stovetop, and the last one is my big pressure canner - and have used them for years - and I'd not do that with any of the four of them - why chance a horrible scalding injury as well as losing a nice piece of equipment to MAYbe save 20 minutes? Just so not worth it IMHO!

I think there's some potential for experimentation here that could benefit the HB community.

Consider all the warnings already given.

I don't know enough about the chemistry of DMS to know how much of an issue it would be, espcially at PC temperatures. But a lot of blowoff is going to happen through the relief vent. Will DMS go with it? I don't know, but its one of the questions to answer. Maybe the higher temperature and pressue does something different to DMS. Maybe it will be worse, maybe better.

Truthfully, I don't know enough about why we boil in the first place to know what would change. Obviously, sanitation is a major reason. A PC would get to higher temperatures and end up potentially more sanitary than a regular boil (which is the primary reason they are used in canning certain types of food). Boiling probably does something important to hops, as well as the proteins in the wort (hot break, etc) and I don't know if that is something that could be sped up with a PC, or if there would be negative side effects.

But imagine this - if you could work out the bugs, you could do an enormous amount of the brewing in a single pot:

1) Mash via BIAB, no sparge.

2) Boil, either under pressure or not (Personaly, for safety, I'd wait until post-hot-break before putting the lid on). Experimentation here would help determine what makes sense, and if we could go any shorter duration. Naturally, hop additions would probably necessitate having the lid off for perhaps the entire boil.

3) Cool, then pitch yeast right in the PC, add your lid. Guys on HBT have been experimenting with fermenting in the brew kettle, and a PC certainly seals tight enough. Some recent discussion leads me to believe fermenting with all the trub in place probably has no ill effect. And with the pressure valve engaged, what changes? Will yeast do a reasonable fermentation job under pressure? I think they might, or we'd never have bottle bombs. And we'd be carbonated when primary fermentation is done! (enough? too much? no idea). The pressure valve could take place of the airlock. Obviously you'd need to watch this closely and have a lot of headroom.

4) Heck, if you had a ball valve on the thing... you could bottle straight from that without adding any oxygen (and possibly not needing priming). Or even use it as a keg.

Notice we haven't racked even once in the whole process, spilling, introducing oxygen, etc.

Obviously you'd want to watch pressure very carefully at every step. There's probably issues to deal with too at every step. But my point here is there's a lot of potential for experimentation. I'm inclined to borrow the wife's 16 qt pressure cooker and try some of this out.

DMS is gross. No thanks, I'll stick with a regular kettle.

I don't know how you could possibly hope to avoid DMS ruining your beer using a pressure cooker.

Agreed - DMS is gross. But I don't know what happens to DMS at the temperatures and pressure we're talking about here. Maybe it concentrates, which would suck. Maybe it breaks down to something else...maybe it vents aggressively, maybe it reacts differently with a lack of oxygen (which is common after the first few minutes of a pressure boil).

The hop additions alone are enough to make the boil itself most practical with the lid off. I'm just saying it might be worth experimentation to find out.

Boil some hops in water and sample. Just a quart of water and a small amount of hops for one hour and taste. Now do that with a pressure cooker. My guess is you will get some nasty extraction. I could be wrong.

If you decide to do this. Start with 10 minutes of boil under pressure. Really that is all you need from a flavor stand point. You should also get fantastic break. Cool enough to drop the pressure and open the lid. As mentioned, one hour boil is minimum for DMS boil off and longer doesn't do a lot more for hops from my understanding, Not a hop head so I could be wrong. Anyhow, that is how I would proceed.

The closest I've done to this is pulling a quart of wort and adding raw sugar to invert it. Since it was only once I must have decided it wasn't worth the effort.

Hops utilization would improve with increased temp from high pressure boiling, but that's the only advantage I can see. Someone suggested fermenting in the PC under pressure, and that's a technique that's been shown to reduce esters (at 1.8 bar gauge around 26 psi). Higher levels if dissolved co2 from increased fermentation head pressure causes inhibition of yeast growth, decreased biomass and a subsequent decrease in esters and fusel alcohols, while maintaining attenuation specification.

That being said, I personally wouldn't try this namely for the lack of volatile evaporation in an enclosed system as others have pointed out.


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EJay said:

Truthfully, I don't know enough about why we boil in the first place to know what would change. Obviously, sanitation is a major reason. A PC would get to higher temperatures and end up potentially more sanitary than a regular boil (which is the primary reason they are used in canning certain types of food). Boiling probably does something important to hops, as well as the proteins in the wort (hot break, etc) and I don't know if that is something that could be sped up with a PC, or if there would be negative side

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Reasons to boil:
1) sanitize the wort
2) decrease wort pH
3) concentrate wort
4) add color and favor through Malliard reactions
5) isomerize alpha acids for bitterness
6) precipitate protien/polyphenols (for haze stability)
7) complex oxalate with calcium (for haze stability and to avoid gushing)
8) evaporate unwanted volatiles
9) halt enzymatic conversion securing wort carbohydrate spectrum (if mash out not done)

Help me out if I missed anything.



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Thanks, I figured there was a bunch of additional reasons for the boil.

I still think the most interesting part would be to see what happens with DMS when boiling in a PC. Like others have said maybe it breaks down.

I have my degree in biochemistry and I am familiar with many of the reactions involved in brewing but the breakdown of DMS is not one that I am familiar with. Does anyone know more on this subject?

I do know that at higher temps and higher pressures many reactions are promoted or inhibited. Being able to boil in a PC could have effects that no one ever realized (good or bad idk...).

Does anyone know how the boiling process takes place in a commercial brewery? I am not familiar with many commercial brewing processes...


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Here is an interesting page on DMS but still doesn't help a lot answering the question of the effects of higher temps and higher pressures.


https://www.homebrewtalk.com/wiki/index.php/DMS



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LandoAllen said:

Does anyone know how the boiling process takes place in a commercial brewery? I am not familiar with many commercial brewing processes...

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They have hoods that actively pump the vapors from boiling off. At least, the ones I have visited seem to.