I think DMS is a brewing myth...

[BeaverBarber]

I’m not the one saying that SMM in barley is negligible, I’m quoting Steven E. Ullrich in his brewing textbook “Barley: Production, Improvement and Uses”. He writes “The flavor threshold of DMS is approximately 50-60 micrograms/Liter. S-methylmethionin (SMM) is the primary precursor of DMS in malt (Yang et al. 1998). The level of SMM in barley is negligible, bit it is synthesized during germination in a reaction between S-adenosyl-L-methionine and methionine. This reaction is catalyzed by L-methionine S-methyltransferase (SMM synthetase). SMM is degraded into DMS under high temperatures during malt kilning and wort boiling. Dimethylsulfide is volatile, and variable amounts will be lost to the atmosphere…etc. etc.” I’m not saying that homebrewers are dumb, but we do have a tendency to believe myths. I believe this is another one. We’re talking about a compound that is so difficult to taste that hardly anyone can spot it. We’re led to believe that this is a big problem in brewing and it just isn’t. We’re told that DMS tastes like a can of corn juice in a light lager; a pack a day smoker with a sinus infection could taste that. I’ve never had that problem, and no one brews drunker than I do. I’ve had every problem under the sun. My 0 minute hop additions turn into 45 minute hop additions, but my beer never tastes like vegetables…unless you count hops as a vegetable. It’s a myth.

[BrewChemistinCO]

The level of SMM in barley is negligible, bit it is synthesized during germination in a reaction between S-adenosyl-L-methionine and methionine. This reaction is catalyzed by L-methionine S-methyltransferase (SMM synthetase). SMM is degraded into DMS under high temperatures during malt kilning and wort boiling. Dimethylsulfide is volatile, and variable amounts will be lost to the atmosphere…etc. etc.”

The way I read that is that in cultivated in the field barley there is negligible SMM but in germination, part of the malting process, it is synthesized.

I agree with you that people tend to believe what they are told but I sincerely doubt this is a brewing myth. There are way too many papers written about it and way too many analytical application notes available for a compound that is completely irrelevant.

[BeaverBarber]

I'm not saying that it doesn't exist. I'm saying it doesn't matter.

[BeaverBarber]

BrewChemistinCO,
Thanks for replying. I was wondering what others might think about this.

Mike

[spiderwrangler]

The level of SMM in barley is negligible, bit it is synthesized during germination..

I read this the same way as BCCO... nothing in the field, but once malted, it is there.

We’re told that DMS tastes like a can of corn juice in a light lager; a pack a day smoker with a sinus infection could taste that.

Not sure that it's a WHOLE can... while I agree that most of the spiked beers are very obvious (more so than the same issues in actual beer), that is kind of the point. If the spiked beer was so subtle that only half of the people trying it could pick it up, it would fail in the purpose of doing spiked beer tastings. As mentioned, people's sensitivities to any off flavor may vary. That being said, corn juice spiking can be dialed back to various levels of concentration to create various levels of DMS character.

[BeaverBarber]

From what I understand about DMS, it's okay to have a little of that character in a lager, but it's unacceptable in an ale. Also, from what I understand you're not likely to get any in an ale and you might get a little in a lager; which is totally acceptable. My point is that DMS doesn't matter.

Is there anyone out there really having problems with their beer tasting like cooked corn or raw vegetables? I'd like to hear how it happened. Because like I said before, I challenge anyone to brew drunker than me, and that includes Justin, and I've never had the problem in 7 years.

[spiderwrangler]

Also, from what I understand you're not likely to get any in an ale and you might get a little in a lager; which is totally acceptable. My point is that DMS doesn't matter.

It's not anything I've had a problem with, but it is something I dislike in beers. I really don't like the character it brings, and while it is 'acceptable' in lagers, they didn't consult me on that! I would have told them it was entirely not acceptable. So from my perspective, if I can take simple steps like boiling vigorously with the lid off, I'm going to do it, whether it really has much of an effect or not. Similarly, hot side aeration may not be as much of an issue as commonly thought, but I'm still not going to splash the hell out of my wort. By the same token, I'm not going to stress and go through extra processes to eliminate an issue that isn't there.

[BeaverBarber]

Hot side aeration? I had to look that one up. Funny. No wonder pro brewers think we're neurotic. But I definitely agree with you about continuing to do what works. I'll have to report the results of my last beer once I taste it because the beer should taste like DMS. I couldn't get the beer to boil...just a heavy simmer. That's what started this whole thing, but after a bit of research, I decided not to worry about it because it seemed like a non-issue. It's fermenting like a champ at 48 ambient and 55 internal temp in my freezer. It's the Terrapin Rye Pale Ale recipe with WLP 833 lager yeast because it's too cold for ale yeast. I've never had that beer, but the recipe looked awesome.