Boil off Rate and DMS in the South

[AllBoosedUp]

On my last batch of beer, a fat tire clone, I got noticeable levels of DMS in my beer. This is kinda worrisome to me since I haven't had it since my very first batch where I made the stupid mistake of boiling with the lid on. :smack: (I actually did a blind smell test between my beer and a actual can of corn and nobody could tell which one was actually my beer...)

Anyways, after that first batch I switched to a propane burner and haven't had any issues with DMS in my last dozen or so batches. I usually boil the hell out of my wort, getting about 2 gallons an hour of boil off but this time I decided to dial it back a little after seeing other peoples less vigourous boils that they claimed to never get any DMS issues with.

My thought is that maybe because I live in central alabama where it averages in the lower 90's with 75% humidity in the summer, the DMS isn't going to boil off as easily. I know that 1.5 gallons per hour is around what most people get for their boil off but would I need to get it higher to carry off enough DMS in high humidity environments? Maybe some other southern brewers have had experience with this problem before.

I don't think it's related to the DMS problems but this batch happened to be my first all grain batch. Though I do remember reading/hearing something about when they condense the wort into extract they actually remove a significant amount of the precursors to DMS in the process.

Since I'm currently doing 60 min boils, should I just switch to 90 min boils and not even worry about it? I have a 10 gallon pot so I have plenty enough room for the extra boil volume.

Thanks,
Andrew

 

[kh54s10]

I don't know for sure. But here in the Northeast I brew on and enclosed porch (all windows and screen door open) and midsummer hit temperatures over 105 degrees in there. I have not had any noticeable DMS issues. The lowest I get is about 1.75 gallons per hour boil off, usually about 2 gallons per hour.

 

[gatomalo]

Here in TX, I'm about 1.3 gallons/hr. So far no DMS issues, but I have been able to get the wort chilled down pretty quickly too. That's going to get harder for me in the coming months.

You may also end up with slightly darker beer the longer you boil.

 

[roastquake]

Here in the SC midlands, I have never had DMS and I regularly do short boils for my no-chill method. Did you use Pilsner malt as your base? It is known to have higher levels for DMS precursors and many of the people who use it swear by 90 minute boils to purge it

 

[AllBoosedUp]

Here in TX, I'm about 1.3 gallons/hr. So far no DMS issues, but I have been able to get the wort chilled down pretty quickly too. That's going to get harder for me in the coming months.

You may also end up with slightly darker beer the longer you boil.

I'm almost positive I'm cooling fast enough as I'm using an immersion chiller and so it's below 140°F less than 10 mins after flameout.


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[AllBoosedUp]

Here in the SC midlands, I have never had DMS and I regularly do short boils for my no-chill method. Did you use Pilsner malt as your base? It is known to have higher levels for DMS precursors and many of the people who use it swear by 90 minute boils to purge it

I used Weyerman 2-row as my base, so using pilsner "shouldn't" have caused it...unless my LHBS gave me the wrong malt. The way it works is I email him my grain bill ahead of time and he has it ready to go when I get there. So that actually could have happened


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[roastquake]

I would suspect that you got Pilsner malt, mainly because I doubt that Weyerman makes a "plain 2-row" malt. I know they have various pilsner malts, pale ale malt, abbey malt, and munich malts. Look into that, I suspect it may be a labeling problem at the HBS, or the employee who packed your order figured that Pilsner would be the closest thing from Weyerman to plain 2-row. Remember there are probably other variables in play

 

[highgravitybacon]

I can't tell you for certain what is causing this off flavor. But I can assure you that neither the zip code, time zone nor weather plays any significant role in this.

Is it actually DMS or the smell of pils malt? An unfortunately high number of BJCP judges can't seem to tell the difference between actual corn vs DMS vs. pils malt, nor can they tell the difference between diacetyl and toffee / caramel from crystal malt. Try a can of cooked peas vs your beer and see if people can identify the difference. If they confuse your beer for cooked peas, you have a problem.

 

[thegreatmaibockaddict]

DMS can also come from bacterial infection, oversparging below 160F, or the underpitching of yeast.

In a hot humid environment, wild baddies may be all over the place, and very very tough to keep out of beer no matter what you do if there are enough present in the air.

Fuel for thought, because it sounds like you don't always have an issue...