DMS causes

So, I notice on all my beers (mainly lagers) brewed with pilsner malt, they take on sort of a funky flavor, I think it’s DMS. I boil for 90 minutes and chill the wort down to the mid 60’s in about 15-20 minutes. Then I let the fermenter sit in the fermentation fridge over night or for 6-8 hours to come down to pitching temp.
I’m kind of wondering if maybe I’m not boiling vigorous enough. I brew 4 gallon batches on an electric stove with a fairly tall and narrow 6.5 gallon kettle. So when it boils, sometimes it’s really vigorous for a second, then not so much. If I have the heat on too high, it foams a bunch and won’t go down. I keep it going fairly consistently, but every once in a while it chills out for a second. Anyway, I usually get about a 1.25 gallon boil off in 90 minutes.
Just wondering if anyone has any thoughts as to how to fix this. I like a nice helles or pilsner, but I don’t want to keep brewing these styles if I am going to keep getting this weird flavor. And maybe that’s why I hate on Rahr pils malt…not because of the malt, but because of my process. Not I think the same flavor is appearing in my beers with Best Pils.

Thanks in advance for any comments or suggestions.

Jesse

How are you chilling? and are you covering the kettle while doing so? If the wort is still hot and you cover the kettle, DMS won’t be able to vaporize and re condenses back into the wort. The other cause of DMS is bacterial but that’ll usually taste a lot stronger. Also, if you taste your gravity sample before fermentation you should be able to check for DMS.

I chill with a chiller, lid off. Takes about 15 minutes to get down to pitching temp on ales and usually let them sit in the fermenter for a while for lagers before pitching. I just wonder, if it’s infection, where it could come from. All co2 lines and disconnects have been cleaned and dried. The only thing there I haven’t messed with is my regulator, but I don’t know how that could be an issue.
Otherwise, I don’t get DMS in beers without pilsner malt, that I can tell.

So it’s probably from not boiling hard enough. Do you use fermcap? That would help with boil-over issues when you turn it up.

I don’t use ferm-cap, but I have some. I mean, it’s not like it’s a simmer or anything, it’s rolling, but not a constant roll. Sometimes it boils hard for a second, then dies down for a second. Perhaps I should try a smaller batch where I’m able to boil hard constantly and see if that makes a difference.
If it’s infection, what causes DMS infection? Gas side should be squeeky clean. Ever since an issue I was having last year, I’m anal retentive about keeping gas side clean (and anything else, for that matter).

I had a similar issue with a cream ale about a year ago. I remember boiling the beejeebers out of that wort for 90 minutes specifically to try and drive off DMS. My chill time probably took closer to 1/2 hour, but this was a 25 gallon batch. Anyway the beer fermented and has a very off-putting canned creamed corn aroma to it.  I tried to lager it, warm it up and CO2 scrub it but ultimately dumped it.  I’ve always leaned towards taking too long to chill as the root of the problem for me on that one.  Only beer I’ve ever dumped.

First question…are you sure it’s DMS?  We may be trying to solve he wrong problem.

Well, I’m not certain it’s DMS, to be honest. I can’t think of what else it would be. It’s something that only seems to show up in beer brewed with pilsner malt.

Can you describe it? DMS is like over cooked vegetables our canned corn. Could it be a sulfur note? Likely you are also using a lager yeast when using pilsner malt so it could be a yeast issue instead of a malt issue.

an experiment you could try to narrow this down would be to brew the same recipe as the last time you had this problem but sub pale malt instead of pilsner. If the problem persists it’s probably the yeast

Jesse,

I had two lagers go South on me and I figured out it was because I left them in the fridge overnight to cool and they got an infection.  Wondering if this could be your case as well.

I ended up buying a Chugger pump at NHC and building a closed system.  Now I cool it to 60F with my IC and tap water and then change the outlet of the hose to a tub with ice water and flip on the pump.  It gets to under 50F in about another 20 minutes.

Dave

If you aren’t getting it in other beers it’s probably not an infection. DMS would be detectable immediately post-boil, so that would be a good indicator. Might be another type of sulfur created during fermentation.

an experiment you could try to narrow this down would be to brew the same recipe as the last time you had this problem but sub pale malt instead of pilsner. If the problem persists it’s probably the yeast

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Great suggestion

Thanks, guys. I’m going to try what Jonathan suggested next and try to brew a lager with pale malt. Actually, the only pale malt I have right now is Warminster floor malted maris otter. I have some left over slurry from the helles I’m drinking now, I wonder if that will be bad to use. I have a pilsner lagering right now that will be ready to drink soon. So, it’ll suck if that one turns out the same way.
But I’ve had the issue with ale yeasts in the past, also, so that points me away from it being yeast.

So if it does happen to the pilsner malt, I guess that means I just shouldn’t use pilsner malt on my current system, huh? I’m not sure how I could get more boil off. It’s a tall narrow kettle, so I wonder if it’s because of that. I get around 3/4 of a gallon boil off per hour, I think.

Boiling off 1.25 gallons over 90 minutes for a 4-gal batch is plenty vigorous.  I boil off around ~1.5 gals for a 10-gal batch in the same time period without DMS issues with pilsener malt.

Hmm, well, that’s interesting. I am running a little experiment where I’m carbonating my current pilsner with a different tank and regulator.
Perhaps this flavor issue is tied to the dark beer issue I posted about in the “Stouts - grain to glass” thread. Hard to say. Hoping it’s not an infection issue. The beers seem fine when I keg them, but it’s hard to tell when they’re uncarbonated and at fermentation temps.

That makes me think it’s something other than DMS. I think you’d get a pretty solid “corn” note at kegging if the problem is DMS. Sorry if I missed it, but did you give any more desciption of the off flavor other than funky? Like Belgian funky?

No, it’s definitely not Belgian funky. If anything, it’s corn like, but I don’t smell it and instantly think CORN. Then again, everyone always says creamed corn and I’m not sure how that differs from regular cooked corn.

Or is it Rolling Rock-y ?  Rolling Rock is a pretty prime example of excessive DMS.  Just trying to picture what you have.

Not sure, but I might go buy a can of that now for the example. All I know is that it’s the same flavor I got in a helles brewed with rahr pils. I thought it was just the malt character but I think it’s something else now.

Unless your sanitation practices are questionable this should not be a problem. I followed that practice for years with never a problem.

Probably a dumb question but … your not boiling with the lid on are you?