do i need to boil 2 row longer than 60 mins

[fluketamer]

i know the consensus is to boil pilsner for 90 mins but what about 2 row . does this hold true for all light grains or is 60 mins more than enough for my 2 row.

 

[kevin58]

I'm not so sure you need to boil worts made with Pilsner malt for 90 minutes these days. And as far as I know it has never been a recommendation to boil wort made with 2-row for 90 minutes.

 

[BrewnWKopperKat]

... While you could go with a shorter boil, the 90 minute boil enhances the blood-red color.

(link)

 

[AkTom]

Not unless you are trying to boil off to get to your correct OG.

 

[RM-MN]

I usually do a 30 minute boil with 2 row.

 

[lumpher]

The reason we used to boil pilsner for 90 minutes is because it had much more dms-causing chemicals in it, and the 90 minute boil would help get rid of that. It is no longer necessary. As far as 90 minutes with 2 row, no. I've done 30 minute boils and been just fine. Some people even do no-boils with it... not me, though. I still boil at least 30 minutes.

 

[jerrylotto]

I assume you're not talking about decoction, which I always do when I'm brewing pilsners.

 

[VikeMan]

The reason we used to boil pilsner for 90 minutes is because it had much more dms-causing chemicals in it, and the 90 minute boil would help get rid of that. It is no longer necessary.

I would still suggest caution with the lowest kilned (lightest) pilsner malts. The big difference between olde time pilsner malts and modern ones is the amount of modification. And modification is not correlated with low DMS precursor. Also, on the brewhouse side, there's more to DMS production/retention than just the boil length. For example, a long whirlpool/steep at high (but non-boiling temps) can increase DMS. The variables can stack up, and degree of kilning is one of those variables.

 

[jerrylotto]

DMS has a vapor point of 100F at standard pressure and does not form an azeotrope with water so as long as your pot is uncovered so it's not recondensing and dripping back in, you should be able to eliminate it even below a boiling point for wort.

 

[VikeMan]

DMS has a vapor point of 100F at standard pressure and does not form an azeotrope with water so as long as your pot is uncovered so it's not recondensing and dripping back in, you should be able to eliminate it even below a boiling point for wort.

Yes, and the longer you wait, the more you lose. (DMS boils away in a halflife-like fashion). But if you're making it faster than you are losing it, it can get back above taste thresholds. In practice, it's never completely eliminated in beer.

ETA: From Bamforth's 1981 paper: "The use of lightly kilned malts containing high levels of SMM, together with extended periods of hot wort settling, can result in levels of DMS in the pitching wort well above the flavour threshold level." Dimethyl Suphide - A Review

 

[AlexKay]

DMS has a vapor point of 100F at standard pressure and does not form an azeotrope with water so as long as your pot is uncovered so it's not recondensing and dripping back in, you should be able to eliminate it even below a boiling point for wort.

It's more complicated than this. In most cases the rate-limiting step is not volatilization of the DMS, but conversion of the SMM precursor to DMS, which has a half-life of 35-40 minutes (depending on pH) at 100 C. The idea with a long boil is to deplete SMM levels so it doesn't convert later, when it's too late to remove the DMS. The half-life doubles approximately every 6 C, so even a bit lower temperature can have a big impact on the amount of SMM remaining, so this is a big deal for high-altitude brewing.

A good rolling boil does increase surface area and speed DMS volatilization somewhat, but it also does a lot of mixing, which ensures there aren't unwanted concentration or temperature variations in the wort. And speaking of temperature variations, depending on heating method and kettle material and cleanliness, the wall of the kettle will always be a bit hotter than 100 C, which means there's a gradient of superheated liquid between the kettle wall and the bulk of the liquid kept at 100 C through evaporation. Even though the volume of superheated liquid will be small, a few degrees over 100 C greatly increases reaction rates. (This can also be a bad thing, causing unwanted Maillard-type reactions.)

If your boil is too short or not vigorous, your wort stand or whirlpool too long or your cool-down too slow, you're eventually going to have a problem, no ifs/and/ors/buts. But exactly when that problem will happen will depend on the specifics of your equipment and process.

 

[Indian_villager]

I forget where I found the paper, but it did have a decay curve for DMS in a known sample. The rate of flux across the top surface of the liquid did impact how fast you'd be below a perceptible threshold. Meaning if you had a weak boil it would take longer to get rid of it, if you are ripping it will be out of there quick. I do 5 gallon batches in an electric kettle with lid and steam condenser, I am able to avoid dms with all pilsner beers in 30 min boils.

 

[Dland]

Besides sufficient boil, one way to avoid DMS is to cool quickly after boil is turned off.

To do this I run an immersion coil in BK until temp drops to 160-170F, this takes less than 10 minutes and about 5 gallons of cold water run slow though coil, for a 10 gallon batch. Resulting water is quite hot and good to save for clean up. Then whirlpool for hot break separation cone. After that, wort is plate cooled to closer to pitching temp and pumped to fermentor.

Anyway, if this is helpful to anyone, good.

Most of my brews have about 50% pilsner malt in grist. I usually boil semi vigorously for 60-90 minutes, mostly depending on what else I have to get accomplished during boil. Anyway, no detectable DMS.

 

[fluketamer]

thank yo for all the responces

 

[odie]

I'm kinda thinking boil is mostly about hops. longer for bittering, less for aroma.

If not for the hops...you could probably go from mash out to the fermenter?

But boil does ensure sterilization...meaning nothing alive in the wort to challenge the yeast. But you just need to reach boil, not stay there for any period of time.

DMS? never studied or thought about that much. But I've always boiled anyway. mash with the lid off?

 

[AlexKay]

I'm kinda thinking boil is mostly about hops. longer for bittering, less for aroma.

If not for the hops...you could probably go from mash out to the fermenter?

But boil does ensure sterilization...meaning nothing alive in the wort to challenge the yeast. But you just need to reach boil, not stay there for any period of time.

DMS? never studied or thought about that much. But I've always boiled anyway. mash with the lid off?

Hop flavor extraction and alpha-acid isomerization, yes. Reduction of SMM precursor and DMS. Killing most unwanted organisms. Protein denaturation, followed by flocculation and thus clarification of the wort (some uncertainty about whether this is good.) Browning reactions (again, could be good or bad) for color and flavor development. And wort concentration. Did I miss anything?

 

[doug293cz]

DMS? never studied or thought about that much. But I've always boiled anyway. mash with the lid off?

Very little, if any DMS in the starting malt. DMS is formed by the breakdown of SMM, which is in the starting malt. The SMM to DMS conversion has a negligible rate below about 170°F, and SMM has a half life of 30-40 minutes (depending on wort pH) at 212°F. This means that half of the SMM can be converted to DMS (which then quickly evaporates, since its boiling point is about 100°F) in the first ~35 minutes of the boil, half of the SMM left after the first ~35 minutes is converted in the second ~35 minutes of boiling, and so on. Any remaining SMM can be converted to DMS by yeast during fermentation, but at ferm temps, DMS does not evaporate readily.

Brew on

 

[VikeMan]

Any remaining SMM can be converted to DMS by yeast during fermentation, but at ferm temps, DMS does not evaporate readily.

I think yeast can convert DMSO to DMS, but hadn't heard that yeast can convert SMM to DMS. Do you know of a scholarly source for the latter?

 

[doug293cz]

I think yeast can convert DMSO to DMS, but hadn't heard that yeast can convert SMM to DMS. Do you know of a scholarly source for the latter?

I'm working from memory, and may have gotten it wrong. But, if residual SMM isn't converted to DMS by something after the boil, then DMS would almost never be an issue. I'll go back and review the few papers I have on DMS.

Brew on

 

[doug293cz]

I think yeast can convert DMSO to DMS, but hadn't heard that yeast can convert SMM to DMS. Do you know of a scholarly source for the latter?

Here's a copy of one paper I have (attached below.) This paper does state that yeast do not convert SMM to DMS, but that yeast does convert DMSO to DMS. Both SMM and DMSO amounts are controlled primarily by the malting conditions - the DMSO being formed by oxidation of DMS formed by the breakdown of SMM during the malting process. I didn't find anything about DMSO being formed during the brewing process by oxidation of DMS, which is formed by breakdown of SMM at high temps.

It does talk about DMS in wort being increased by whirlpooling at just below boiling temps under conditions which prevent the DMS from evaporating (as it does during the boil.)

Brew on