Author Topic: Lid on or off during boil?  (Read 6236 times)

Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11654
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Lid on or off during boil?
« Reply #30 on: September 19, 2013, 08:31:18 AM »
Stacks with exhaust vents AND a condensate drip ring.  Plus the kettle is domed.  If you leave the flat lid on even partially, you'll notice that the underside is covered in steam condensation.  That's the stuff that you don't want to fall back into your wort.

Just gotta ask...have you had a problem from boiling with a partially covered kettle?  Because I haven't.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

Offline bluesman

  • Global Moderator
  • I must live here
  • *****
  • Posts: 8678
  • Delaware
    • View Profile
Re: Lid on or off during boil?
« Reply #31 on: September 19, 2013, 09:51:32 AM »
I typically leave the lid off for the aforementioned reasons (DMS). I think as long as you get a decent evaporation rate, you'll drive off the unwanted precursers to DMS formation upon cooling.
Ron Price

Offline monkeypimp

  • 1st Kit
  • *
  • Posts: 8
    • View Profile
Re: Lid on or off during boil?
« Reply #32 on: September 19, 2013, 11:53:24 AM »
So Rolling Rocks flavor was caused by faulty exhaust which allowed some condensation back into the boil..Does that mean any condensation that drips back in causes DMS?   If I use a Hop Spider  won't some condensation likely drip back in? Will this cause DMS?

Just trying to learn! so don't beat me up for any silly questions.

Offline narvin

  • Senior Brewmaster
  • ******
  • Posts: 1232
  • Baltimore
    • View Profile
Re: Lid on or off during boil?
« Reply #33 on: September 19, 2013, 11:57:12 AM »
Stacks with exhaust vents AND a condensate drip ring.  Plus the kettle is domed.  If you leave the flat lid on even partially, you'll notice that the underside is covered in steam condensation.  That's the stuff that you don't want to fall back into your wort.

Just gotta ask...have you had a problem from boiling with a partially covered kettle?  Because I haven't.

I have had DMS issues before from inadequate boil-off when using Pilsner malt.  This was caused by a few different things, from burner problems to an extremely high humidity environment combined with bad ventilation.  I'm sure that leaving the lid on partially can be okay in many cases, but it's something that I think you do need to be careful about because it really can cause a problem in the real world (unlike HSA  ;) )
Please do not reply if your an evil alien!
Thanks
Chris S.

Offline narvin

  • Senior Brewmaster
  • ******
  • Posts: 1232
  • Baltimore
    • View Profile
Re: Lid on or off during boil?
« Reply #34 on: September 19, 2013, 11:58:32 AM »
So Rolling Rocks flavor was caused by faulty exhaust which allowed some condensation back into the boil..Does that mean any condensation that drips back in causes DMS?   If I use a Hop Spider  won't some condensation likely drip back in? Will this cause DMS?

Just trying to learn! so don't beat me up for any silly questions.

Well, if some drips back in, it should be able to boil off again.  It's more about getting the proper amount of ventilation... not enough and too much DMS precursor will remain, like Ron said.
Please do not reply if your an evil alien!
Thanks
Chris S.

Offline reverseapachemaster

  • Brewmaster
  • *****
  • Posts: 909
    • View Profile
    • Brain Sparging on Brewing
Re: Lid on or off during boil?
« Reply #35 on: September 20, 2013, 07:22:05 AM »
Once the SMM boils out it doesn't matter if the condensation drips back in.
Heck yeah I blog about homebrewing: Brain Sparging on Brewing but I'm also a lawyer: The Kielich Law Firm

Online morticaixavier

  • Official Poobah of No Life.
  • *
  • Posts: 5677
  • Davis, CA
    • View Profile
    • The Best Artist in the WORLD!!!!!
Re: Lid on or off during boil?
« Reply #36 on: September 20, 2013, 07:30:25 AM »
Once the SMM boils out it doesn't matter if the condensation drips back in.

in that case it shouldn't matter at all if you had a totally unventilated (lid on pot).

What is your support for this statement?
"Creativity is the residue of wasted time" - A. Einstein

Jonathan I Fuller

Offline narvin

  • Senior Brewmaster
  • ******
  • Posts: 1232
  • Baltimore
    • View Profile
Re: Lid on or off during boil?
« Reply #37 on: September 20, 2013, 07:37:25 AM »
Once the SMM boils out it doesn't matter if the condensation drips back in.

In theory, that's correct from what I've read. If you boiled for 60-90 minutes uncovered and then put the lid on and continued to boil, there would be little/no SMM left and hence no DMS in your beer.

Now, if you have condensate with SMM dripping back in throughout the boil, you're only removing a percentage of it and it's going to take longer for it to be reduced/removed via boil-off.  How long in practice probably depends on a lot of factors.
Please do not reply if your an evil alien!
Thanks
Chris S.

Offline erockrph

  • Brewmaster General
  • *******
  • Posts: 2414
  • Chepachet, RI
    • View Profile
    • Critical Tastings
Re: Lid on or off during boil?
« Reply #38 on: September 20, 2013, 08:24:53 AM »
Once the SMM boils out it doesn't matter if the condensation drips back in.

In theory, that's correct from what I've read. If you boiled for 60-90 minutes uncovered and then put the lid on and continued to boil, there would be little/no SMM left and hence no DMS in your beer.

Now, if you have condensate with SMM dripping back in throughout the boil, you're only removing a percentage of it and it's going to take longer for it to be reduced/removed via boil-off.  How long in practice probably depends on a lot of factors.

So what makes both sides of this argument seem a bit dubious to me is that there are assumptions being made regarding the behavior of SMM in its vapor state. Once boiling, the SMM and water vapor are separate - the SMM is no longer dissolved in the water because they are both in a gaseous state. When the water condenses on the lid it doesn't contain any SMM immediately. The SMM would then need to redissolve in the condensate, or condense out itself before redissolving. The rate at which that happens will be determined by things like boiling point, hydrophilicity, etc of SMM.

I'm not sure the research has been done already, but I would imagine you would need to test for varying factors (length of boil, boiloff rate, atmospheric humidity and temp, surface area and shape of lid, yada yada), then run the condensate through HPLC to determine the amount of SMM over time. Or you can just brew some beer and use your palate.
Eric B.

Finally got around to starting a homebrewing blog: The Hop Whisperer

Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11654
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Lid on or off during boil?
« Reply #39 on: September 20, 2013, 08:27:28 AM »
I'm not sure the research has been done already, but I would imagine you would need to test for varying factors (length of boil, boiloff rate, atmospheric humidity and temp, surface area and shape of lid, yada yada), then run the condensate through HPLC to determine the amount of SMM over time. Or you can just brew some beer and use your palate.

Yep, that's what I did after reading about partial covering being OK.  I don't know about you guys, but I usually don't measure my beer...I drink it!
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

Offline yso191

  • Brewmaster
  • *****
  • Posts: 632
  • Yakima, WA
    • View Profile
Re: Lid on or off during boil?
« Reply #40 on: September 23, 2013, 06:56:39 AM »
As a result of this conversation, I emailed Muntons and asked them.  Here is the response I received:

Dear Steve,
 
SMM and DMS are volatile compounds and the temperatures and processes involved in the production of our liquid and dried extracts will drive off such compounds.
 
We have never tested for these compounds in the final products, but it is the consensus of our technical team that it is extremely unlikely that they will be found.
 
Best Regards,
 
Steve Brown
Technical Sales Support
Muntons Plc


Confirmation, though not absolute.
Steve

Offline klickitat jim

  • I spend way too much time on the AHA forum
  • ********
  • Posts: 2629
    • View Profile
Re: Lid on or off during boil?
« Reply #41 on: September 23, 2013, 07:51:44 AM »
Consensus these days IS fact.

Offline ynotbrusum

  • Senior Brewmaster
  • ******
  • Posts: 1003
  • Da mihi sis cerevisiam.
    • View Profile
Re: Lid on or off during boil?
« Reply #42 on: September 23, 2013, 11:33:20 AM »
As a result of this conversation, I emailed Muntons and asked them.  Here is the response I received:

Dear Steve,
 
SMM and DMS are volatile compounds and the temperatures and processes involved in the production of our liquid and dried extracts will drive off such compounds.
 
We have never tested for these compounds in the final products, but it is the consensus of our technical team that it is extremely unlikely that they will be found.
 
Best Regards,
 
Steve Brown
Technical Sales Support
Muntons Plc


Confirmation, though not absolute.

So as long as we brew like Muntons makes its extract, we are safe.  Good to know, but do they take the lid off?
Hodge Garage Brewing: "Brew with a glad heart!"

Offline denny

  • Administrator
  • I must live here
  • *****
  • Posts: 11654
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: Lid on or off during boil?
« Reply #43 on: September 23, 2013, 12:31:34 PM »
As a result of this conversation, I emailed Muntons and asked them.  Here is the response I received:

Dear Steve,
 
SMM and DMS are volatile compounds and the temperatures and processes involved in the production of our liquid and dried extracts will drive off such compounds.
 
We have never tested for these compounds in the final products, but it is the consensus of our technical team that it is extremely unlikely that they will be found.
 
Best Regards,
 
Steve Brown
Technical Sales Support
Muntons Plc


Confirmation, though not absolute.

So as long as we brew like Muntons makes its extract, we are safe.  Good to know, but do they take the lid off?

It won't matter as the compounds have already been removed.
Life begins at 60.....1.060, that is!

www.dennybrew.com

The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe

Offline ynotbrusum

  • Senior Brewmaster
  • ******
  • Posts: 1003
  • Da mihi sis cerevisiam.
    • View Profile
Re: Lid on or off during boil?
« Reply #44 on: September 23, 2013, 07:08:20 PM »
I meant in terms of all grain brewing - extract is clearly free of DMS issues, as long as you use Muntons, anyway!
Hodge Garage Brewing: "Brew with a glad heart!"