Author Topic: Lid on or off during boil?  (Read 6217 times)

Offline Joe Sr.

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Re: Lid on or off during boil?
« Reply #15 on: September 17, 2013, 12:27:31 PM »
I always take the safe route and keep the lid off.
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Offline monkeypimp

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Re: Lid on or off during boil?
« Reply #16 on: September 17, 2013, 12:28:00 PM »
I only in the last year made the move from the stove with a 4 gallon pot to the garage with a 15 gallon pot and never noticed any off taste before since I always brewed with the lid off.  I do partial mash....and usually do IPA's  which i have never noticed any off tastes.   But recently have made a couple of pale ale and they have all had an off flavor that i can't put my finger on.  It almost has a "burnt" type flavor...

 I do usually leave my lid cracked or the pot tends to want to boil over...but condensation does from and drips back in.....looks like my methods have changed!

Online morticaixavier

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Re: Lid on or off during boil?
« Reply #17 on: September 17, 2013, 12:34:22 PM »
I agree with all of the above.  However it is unimportant if you are brewing with Extract.  It really only applies to all-grain brewing since the DMS is gone out of extract.

don't the precursors begin to reform once you get the wort above the magic temp? or is that another myth?

Morticai, You are seriously beyond my experience level, but my understanding is that the precursor to DMS, which is SMM is entirely converted in a 90 minute boil.  I'm sure that the process of getting DME or LME goes way beyond what it takes to convert all the SMM to DMS and then blow that off.  However, I always take the safe route and defer to those more advanced than I.

I am pretty sure that anything I know about this is heresay from this forum.

In fact, here is a discussion about this very thing.

http://www.homebrewersassociation.org/forum/index.php?topic=33.0

I only in the last year made the move from the stove with a 4 gallon pot to the garage with a 15 gallon pot and never noticed any off taste before since I always brewed with the lid off.  I do partial mash....and usually do IPA's  which i have never noticed any off tastes.   But recently have made a couple of pale ale and they have all had an off flavor that i can't put my finger on.  It almost has a "burnt" type flavor...

 I do usually leave my lid cracked or the pot tends to want to boil over...but condensation does from and drips back in.....looks like my methods have changed!


What is your batch size?  I boil 40 liter batches (~49 liter preboil for a 90 minute boil) in a 50 liter pot and manage to avoid the worst of the boil overs with flame control. You really only need to see the wort turning over, it doesn't have to be leaping out of the pot.
"Creativity is the residue of wasted time" - A. Einstein

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Offline monkeypimp

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Re: Lid on or off during boil?
« Reply #18 on: September 17, 2013, 12:38:21 PM »
I make both 5 gallon and 10 gallon batches.....with the lid on and me not paying attention a 5 gallon batch will boil over....been done more than once!

Online morticaixavier

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Re: Lid on or off during boil?
« Reply #19 on: September 17, 2013, 01:07:21 PM »
I make both 5 gallon and 10 gallon batches.....with the lid on and me not paying attention a 5 gallon batch will boil over....been done more than once!

Oh yeah, with the lid on I can imagine. the only time I have had a boil over on a 5 gallon batch was when there was a lot of wheat in the grist... and I wasn't paying attention.
"Creativity is the residue of wasted time" - A. Einstein

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Offline denny

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Re: Lid on or off during boil?
« Reply #20 on: September 17, 2013, 01:14:26 PM »
Partially covered is fine.  Think of how many breweries have enclosed kettles.  But a study done many years ago concluded that you want at least 15% of your kettle surface uncovered.
Breweries have enclosed kettles, but they have stacks and probably exhaust fans too :) But still I'm sure partially covered is fine. The important point is letting steam escape before it condenses and returns to the wort.

Correct on the stacks and vents, which is why 15% open works.
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Offline narvin

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Re: Lid on or off during boil?
« Reply #21 on: September 17, 2013, 02:31:27 PM »
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.
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Offline ynotbrusum

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Re: Lid on or off during boil?
« Reply #22 on: September 17, 2013, 05:48:40 PM »
I leave it on up to the boil, but propped against the other side, so it is at least 25% open.  It gets to a boil faster and I pull it off during the full boil for a while. Never any problems with DMS.
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Offline factory

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Re: Lid on or off during boil?
« Reply #23 on: September 18, 2013, 10:13:26 AM »
For monkeypimp- DMS tastes similar to creamed corn. Rolling Rock has that flavor defect. If you never picked it up in your beer, or Rolling Rock, you my have a very high sensitivity, or be flavor blind to it (some people are).
Now I know why I don't like Rolling Rock.

Offline jeffy

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Re: Lid on or off during boil?
« Reply #24 on: September 18, 2013, 02:22:38 PM »
For monkeypimp- DMS tastes similar to creamed corn. Rolling Rock has that flavor defect. If you never picked it up in your beer, or Rolling Rock, you my have a very high sensitivity, or be flavor blind to it (some people are).
Now I know why I don't like Rolling Rock.
The story goes that they had a curve or kink in the exhaust chimney over the kettle and condensation would drop back in, causing the DMS precursor.  When they opened a new brewery without this fault they lost so much customer base because "the beer wasn't the same" that they had to incorporate the defect into the new system.
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Offline klickitat jim

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Re: Lid on or off during boil?
« Reply #25 on: September 18, 2013, 02:52:43 PM »
Cool story! Makes you wonder

Offline BrewArk

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Re: Lid on or off during boil?
« Reply #26 on: September 18, 2013, 03:51:41 PM »
For monkeypimp- DMS tastes similar to creamed corn. Rolling Rock has that flavor defect. If you never picked it up in your beer, or Rolling Rock, you my have a very high sensitivity, or be flavor blind to it (some people are).
Now I know why I don't like Rolling Rock.
The story goes that they had a curve or kink in the exhaust chimney over the kettle and condensation would drop back in, causing the DMS precursor.  When they opened a new brewery without this fault they lost so much customer base because "the beer wasn't the same" that they had to incorporate the defect into the new system.

Not to mention that AB bought them out and is brewing it in their breweries.  I've heard that they sometimes have trouble making it taste that way in a well built brewery.
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Offline HoosierBrew

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Re: Lid on or off during boil?
« Reply #27 on: September 18, 2013, 04:59:45 PM »
Hey BJCPs - on this topic, I've heard 2 or 3 times over the years that Rolling Rock is used as the reference sample and/or test question for DMS.  Any truth to this?  Just curious.
Jon H.

Offline hopfenundmalz

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Re: Lid on or off during boil?
« Reply #28 on: September 18, 2013, 05:41:57 PM »
We had Rolling Rock in our study group, and yes it had DMS, even brewed by AB. They learned how to do it.
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Offline reverseapachemaster

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Re: Lid on or off during boil?
« Reply #29 on: September 19, 2013, 07:06:01 AM »
I usually boil with the lid half on. No Rolling Rock clones in my house.
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