Scientific Brew

[stroker351w]

I was thinking about how to take brewing to the next level. What would the effects on the beer be if it was boiled under a vacuum or under pressure, like a pressure cooker? Could it help the hops breakdown to get closer to a 0.9999 FG?

 

[hopsalot]

from HBTwiki
Covering the brew kettle during the boil prevents DMS from evaporating, and results in high levels of DMS in the finished beer.

 

[Gameface]

under vacuum you would boil at a lower temp and would lose a lot more to evaporation.

 

[MisterTipsy]

Yum...sulfur beer.

 

[rifraf]

from HBTwiki
Covering the brew kettle during the boil prevents DMS from evaporating, and results in high levels of DMS in the finished beer.

Not an issue with extract brewing from what I understand.

 

[stroker351w]

under vacuum you would boil at a lower temp and would lose a lot more to evaporation.

If it's in a vacuum, you would have a closed system and not have any way for evaporation to occur.

 

[Gameface]

If it's in a vacuum, you would have a closed system and not have any way for evaporation to occur.

So no head space at all?

Your wort will continue to evaporate at a lower temp effectively eliminating your vacuum. The only way to stop the gas (evaporated wort) from causing pressure would be to draw it off through your vacuum source (a turbo pump?). So your wort will evaporate, no way to stop that. Then I guess you'd have to have a sanitary pump so the evaporation could pass through it and condense on the other side before adding it back into the wort.

And all to gain what?

 

[Denny]

under vacuum you would boil at a lower temp

And get less hop utilization as a result.

 

[Denny]

I was thinking about how to take brewing to the next level. What would the effects on the beer be if it was boiled under a vacuum or under pressure, like a pressure cooker? Could it help the hops breakdown to get closer to a 0.9999 FG?

What does "hop breakdown" have to do with FG?

 

[bdh]

Boiling under pressure would probably give weird effects. One of the points of the boil is to drive off undesirable volatile compounds (like DMS listed above - also chlorine comes to mind), under pressure it'd be harder to drive these out. If anything, I'd guess that boiling under pressure would raise the FG. The temperature of the wort would be raised, so you'd get more Maillard reactions and caramelization which would leave you with more nonfermentibles...

 

[Denny]

Boiling under pressure would probably give weird effects. One of the points of the boil is to drive off undesirable volatile compounds (like DMS listed above - also chlorine comes to mind), under pressure it'd be harder to drive these out. If anything, I'd guess that boiling under pressure would raise the FG. The temperature of the wort would be raised, so you'd get more Maillard reactions and caramelization which would leave you with more nonfermentibles...

If you don't remove chlorine before boiling your wort, it's too late.

You can't get kettle caramelization. That takes a temp of at least 360F, which you won't see with wort.

 

[bdh]

If you don't remove chlorine before boiling your wort, it's too late.

You can't get kettle caramelization. That takes a temp of at least 360F, which you won't see with wort.

Why is it too late if you have chlorine in the wort going into the boil? Doesn't conventional wisdom claim that chlorine comes out during the boil (chlormines don't)?

I agree you probably won't get bulk caramelization in a pressure cooker, but I'd still bet you get more nonfermentibles than with a standard boil. Maltose caramelizes at a pretty high temp, but other sugars (like fructose) will caramelize at a lower temp, and there will still be lots of random proteins floating around which will be more likely to bind up sugar at a higher temp.

 

[MotorcycleMatt]

I was thinking about how to take brewing to the next level. What would the effects on the beer be if it was boiled under a vacuum or under pressure, like a pressure cooker? Could it help the hops breakdown to get closer to a 0.9999 FG?

Why would you want a .9999 fg? Id don't want my beer as thin as water

 

[Denny]

Why is it too late if you have chlorine in the wort going into the boil? Doesn't conventional wisdom claim that chlorine comes out during the boil (chlormines don't)?

Because by then you will have formed chlorophenolic compounds in the wort. You need to boil the water before you use it.

 

[Xpertskir]

Because by then you will have formed chlorophenolic compounds in the wort. You need to boil the water before you use it.

I unfortunately have a couple batches that prove this point...even with extract brewing.

Issue since addressed but my pipeline and psyche will take longer to recover.

 

[KISS Brew]

Why would you want a .9999 fg? Id don't want my beer as thin as water

This was my immediate reaction, too.

 

[passedpawn]

Why is it too late if you have chlorine in the wort going into the boil? Doesn't conventional wisdom claim that chlorine comes out during the boil (chlormines don't)?

Actually, chlorimines boil off too if you boil your water for about 15 minutes before adding to mash.

http://hbd.org/ajdelange/Brewing_articles/BT_Chlorine.pdf

"Once wort sugars contact the chlorine or chloramines, they complex and are no longer volatile. Then its impossible to get them out. You are then left with chlorophenols in your beer." - mabrungard

 

[bmbigda]

several breweries use low pressure boiling kettles (Harpoon is one of them). You seem to be moving in the opposite direction

 

[bdh]

Actually, chlorimines boil off too if you boil your water for about 15 minutes before adding to mash.

http://hbd.org/ajdelange/Brewing_articles/BT_Chlorine.pdf

"Once wort sugars contact the chlorine or chloramines, they complex and are no longer volatile. Then its impossible to get them out. You are then left with chlorophenols in your beer." - mabrungard

Hmm, good to know. That article looks interesting. I'll have to give it a read when I have more free time...

 

[passedpawn]

Hmm, good to know. That article looks interesting. I'll have to give it a read when I have more free time...

That's an article by one of our members here, AJ Delange.

 

[Gameface]

several breweries use low pressure boiling kettles (Harpoon is one of them). You seem to be moving in the opposite direction

How do they accomplish low pressure, and what sort of "low pressure" are we talking about? I could see going from 760Torr to maybe 500Torr. I can't imagine going much lower than that.

What do they accomplish by low pressure boiling?

 

[zachattack]

So no head space at all?

Your wort will continue to evaporate at a lower temp effectively eliminating your vacuum. The only way to stop the gas (evaporated wort) from causing pressure would be to draw it off through your vacuum source (a turbo pump?). So your wort will evaporate, no way to stop that. Then I guess you'd have to have a sanitary pump so the evaporation could pass through it and condense on the other side before adding it back into the wort.

And all to gain what?

:rockin:

Turbomolecular pumps require roughing pumps and are only good for ultra high vacuum. For this application I'd suggest a large diaphragm pump since it can handle moisture. You could easily trap the vapor with a liquid nitrogen cold trap or something similar. It all seems pointless to me as well, but I worked with vacuum systems for a couple years. They're fun.

The only thing I can think of is maybe if they can boil at a lower temperature, fewer desirable volatiles will boil off (hop oils)? But obviously there's plenty of undesirables you want to drive off...