Author Topic: DMS  (Read 5225 times)

Offline Broohoose

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DMS
« on: April 29, 2010, 01:56:46 PM »
The last two lighter styles I have brewed (an amber and a Scottish 40) seem to have the same flavor that I guess could be described as corny.  After boiling for 65 minutes, I turn off the heat, stir to whirlpool, then cover for 20 minutes before pumping through the counterflow.  Should I not cover after whirlpool, boil longer, or punt.  I get awesome trub/hop cones on the false bottom, so I think that part is right.  Also, I am a sanitation geek so I don't think that is the source.  Any advise would be greatly appreciated.

Thanks!
Ross

Offline sickbrew

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Re: DMS
« Reply #1 on: April 30, 2010, 07:27:11 PM »
DMS can occur from a weak boil.  If you have a righteous rolling boil, most of those DMS chemicals literally evaporate.  How would describe your boil.  Some brewers with small pots limit there boil vigor to prevent those nasty boil over's but at the expense of DMS.

cheers

Offline Pirate Point Brewer

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Re: DMS
« Reply #2 on: May 01, 2010, 04:02:00 AM »
Did you boil with the pot covered?  That’s where you can get a very noticeable amount in the brew,

Preston
In Fall and Winter, we burn wood in the fireplace and brew beer.
In Spring & Summer, we're on the water or walking the beach!
 Then back at the dock we create a reason to brew!

Offline MaltLicker

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Re: DMS
« Reply #3 on: May 01, 2010, 06:23:12 AM »
...have the same flavor that I guess could be described as corny.  After boiling for 65 minutes, I turn off the heat, stir to whirlpool, then cover for 20 minutes before pumping through the counterflow.  Should I not cover after whirlpool, boil longer, or punt. 

All malt has the pre-cursor to DMS, which is then formed when heated above 140F.  So,

  • Full, rolling boils >60 mins (90 mins for pale lager malts)
  • Boil uncovered, and do not cover the wort during chilling until it is well below 120F, as DMS is still being formed from 212F down to ~140F, and possibly dripping back into wort with condensation off lid


Could you adopt some type s/s scrubby thing in the boiler so that you didn't have to whirlpool hot wort (hot-side aeration risk) and also wait 20 minutes to start chilling?  It's generally preferred to whirlpool chilled wort. 

Offline Broohoose

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Re: DMS
« Reply #4 on: May 03, 2010, 08:29:46 AM »
Thanks for the tips. guys.  I always boil with the pot uncovered and I get between 10-12% evaporation, so I think the boil is good.  I will definitely be boiling the 90 minutes and leaving the pot uncovered while I am chilling.  One more question, I have a false bottom (from N. Brewer for Sankes) in my boil kettle, so do I even need to stir to whirlpool after the boil before I pump it through the counterflow chiller?

You guys are a great resource.  Much appreciated.

Ross

Offline Pirate Point Brewer

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Re: DMS
« Reply #5 on: May 03, 2010, 08:45:45 AM »
Broohoose,

I'll deffer to "Those Who Know" ::) I'm a small batch brewer using a 5 gal igloo MLT and braid. I always whirlpool the boiler as I siphon. No valves needed to fry turkey's ;D

Good Luck,

Preston
In Fall and Winter, we burn wood in the fireplace and brew beer.
In Spring & Summer, we're on the water or walking the beach!
 Then back at the dock we create a reason to brew!

Offline MaltLicker

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Re: DMS
« Reply #6 on: May 03, 2010, 09:06:16 AM »
One more question, I have a false bottom (from N. Brewer for Sankes) in my boil kettle, so do I even need to stir to whirlpool after the boil before I pump it through the counterflow chiller?

I do it b/c I drain from the side valve, but I have friends that drain from the center, beneath a false bottom or braid, and they like the "cone" of debris that forms over the drain.  The big stuff falls first and helps to filter the rest. 

 

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