I think DMS is a brewing myth...

[Stinkfist]

I doubt you will have a DMS issue with that beer, now if it was 90% pilsner you would probably have a problem, so do not consider your beer the tell all on whether DMS is real..

I agree with the post above the SMM is being converted to DMS if you do not boil long enough and or vigorous enough you have not converted and boiled off all the DMS as it will continue to convert to DMS even after you turn off the heat.

[BeaverBarber]

Similarly, Bamforth has spoken about working with UK breweries who measure the amount of DMS because they *want* some in their beers, to replicate the European flavours.

If this is true, this is my point exactly. It's so difficult to get that flavor in your beer, breweries in the UK are enlisting the help of a professional to obtain it. I'm guessing that British lagers don't taste "lagery" enough so they're asking Bamforth for help.

I'm not saying don't boil. We have to boil to sterilize, isomerize and let melanoidins harmonize, and if you can do that, you can rest assure that you've driven off the DMS boogie man.

[BeaverBarber]

I'm most likely missing something here, 'cause this chemistry stuff tends to escape me a little, but my understanding was that heating SMM in the kettle creates DMS.

The boil then in turn drives off the DMS. So while the OP might be correct in saying DMS is driven off so easily it's hardly worth worrying about, it's the SMM being continuously converted throughout the boil that causes the problem.

It seems very simple now. Putting it all together, SMM is created while the grain is growing. This amount is very negligible, but in one region, Central Europe, it seems a bit less negligible. During the kilning process, some or all SMM is destroyed. If a grain is very lightly kilned, the SMM is not destroyed which later creates DMS in the boil. There is only a finite amount of SMM in any grain so it doesn't go on creating DMS forever; just until it's gone. Lightly kilned, British, American, Canadian, and Austrailian malts don't contain much SMM so there is very little associated DMS. British malts in particular have practically no SMM at all. However, in Central Europe barley has been selectively bred to include a larger amount of SMM, enough to survive a long boil, because they enjoy a tiny bit of DMS flavor in their beer. I'm saying that they've selectively bred it that way because they're the lone outlyers. Homebrewers using a Central European malt, like Weyermann Munich Malt, in their American Pale ale could run into a bit of a DMS problem, but it will be very slight, and undetectable to most who are not trying desperately to find a flaw. I hope that sums it up. Love,

The Beaver Barber

[herbaljoe]

I really like this theory as I too have long suspected that DMS production & reduction was not fully understood by us homebrewers. Here are some of my experiences:

I've brewed a Berliner Weisse with a 10 minute boil that had absolutely no DMS (and I can usually sense it at low levels).

I've brewed a Blond ale with American 2-row and a 100 minute boil that had noticeable DMS in the finished beer. Happened on 2 separate occasions with this recipe.

I've had massive amounts of DMS in beers which also happened to have very long lag times between pitching yeast and visible fermentation. Most of them were lagers and the grain bills varied.

I once had a starter that never took off (must have been a shitty pack of yeast) and when I smelled it 4 days later is was the most DMS ridden thing I've ever smelled (and was still totally unfermented). (My starters never smell like DMS normally, and I make them using light DME.)

I too have smelled a very corny aroma from the boil distillate.

So, take it for what it's worth... In my opinion, the OP is on to something in that the boil may not be the most important part when it comes to reducing DMS. My current theory is that (for whatever reason that I haven't looked deeply into yet) the longer the lag phase, the more DMS you get. A local pro also told me once that DMS is still being produced prior to fermentation while it's sitting in the carboy and this seems to match up with my experiences. Lagers often have a longer lag phase as well. I think one of the keys to fighting it is to add plenty of oxygen at pitching time and make sure your yeast is really healthy and has the proper nutrients... especially for lagers! I think a healthy fermentation actually drives off a significant amount of DMS as well which seems to go along with this theory.

I'm eager to hear the results when you taste your weakly boiled beer! Did you happen to take a temp reading while it was simmering? BTW, I brew at about 1 mile above sea level so my boils are never higher than 204F.

[brewinhard]

Joe,

I too have noticed this with my no boil berliner weisse's before. Have never noticed ANY DMS in them and neither have judges at many comps (this recipe has 50% german pilsner malt too). I do also agree that a vigorous fermentation can help to "blow off" and scrub out a lot of the DMS that might be present in the wort before fermentation.

I have always gotten pretty vigorous ferments with my 100% lacto fermentations for my BW's which could help explain the lack of DMS in a no boil beer. Yet longer lag times (ie with lagers and sometimes other ales) can lead to sluggish fermentations which could leave some DMS behind in the finished product.

[BeaverBarber]

I'm eager to hear the results when you taste your weakly boiled beer! Did you happen to take a temp reading while it was simmering? BTW, I brew at about 1 mile above sea level so my boils are never higher than 204F.

I didn't detect any DMS at all, but I didn't use any pilsner malt, and my fermentation went very strong and fast for a lager. The beer is basically finished and going through a diacetyl rest now, and it's only been 6 days since pitching. I didn't take any temperature readings in the boil, but it was weak enough that I was concerned that I shouldn't even waste my yeast starter and thought that I should start over. You could be on to something with a relationship between DMS flavor and poor fermentation. Well controlled, well aerated, properly pitched, and strong fermentations rarely result in off flavors.