Lid on or off when doing full boils?

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bkov

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When doing full boil extract brews, is it better to leave the lid on or off? thanks
 
I've always been told you should never leave the lid on during a boil as one of the benefits of the boils is the boiling off of a lot of things you don't want in the beer. If you leave the lid on, the steam will condense on the lid and drip all of those nasties back into your beer.

Lid off
 
Keep in mind that for an extract brew it has already been boiled so that the DMS should be gone. I'd boil with the lid off anyway just to ensure that any more that is generated is driven off, but I don't think it's as critical as with AG.
 
Keep in mind that for an extract brew it has already been boiled so that the DMS should be gone. I'd boil with the lid off anyway just to ensure that any more that is generated is driven off, but I don't think it's as critical as with AG.

But remember that heat is what causes wort to produce DMS. Taht's why rapidly cooling the wort below 150F is so important. 150-212F is where DMS production happens.

So when you boil the extract, it could produce DMS again, especially if the extract is based heavily on Pilsner malt.
 
I have been lurking here long enough that you would think I knew what DMS is, but I don't. Can anyone help a newb out?
 
Have to confess that my first (and only so far) AG brew was done with the lid half on, half off! :) It's almost ready to keg now and tastes awesome but my quantities were somewhat out, ended up with about 25l when I was aiming for 23.5l. Apologies for metric. However, SG was 1.044 at the start so should be a nice 4.5% or so brew when done.
 
I, while still doing partial boil extract kits, find that if I leave the lid on that I get boilovers. If I put the lid on till the boil starts and then remove it for the remainder, it boils but doesn't come close to foaming up and allows my apartment to fill with the sweet smell of wort.

ymmv
 
I leave the lid on until my 5-gal boil is at 200F+, then the lid comes off and when I get the bubbling a few minutes later, in go the hops, specialty grains and (usually part of) the extract.
 
I brew outside, or if its raining or windy, in my garage with the door open, so i leave the lid on till i get to boiling then put the lid half on half off to let out the nasties but help prevent anything from falling in, leaves pine needles, bugs etc... just my 2 pesos
 
I usually leave the lid on as far as I can just because it uses less fuel. I also don't want debris falling in it either. Of course, I was unaware of this DMS so practices will prob. change. Kyle
 
I brew outside too. As with the others, I leave my lid on until it gets to boiling and then set it ajar to prevent boil overs but still protect from UFOs.;)

-Jason
 
With the wind in my open back yard and the weak output of my electric stove I leave the lid partially on to minimize evaporation but let the bulk of the nasties out.
 
Lid stays on til the boil starts. Then it comes off for the duration.

This. Since I only have a 7 gallon kettle right now, I get pretty full after 5+ gallons of water, and then all of either your extract or DME. I like to have a bit of a boiloff to get me down around 5 gallons. Usually I have to add half a gallon or so if I do a vigorous boil for the hour.
 
Anyone know of any studies on this? I'm not sure I trust the wiki entirely on this one. It says you have to boil for 100 minutes uncovered to drive it off but then says its boil point is 99F and it is volatile. You would think it would be driven off after a few minutes.

(CH3)2S
H3C-S-CH3
Boiling Point: 99oF
Density: 0.848
Flavor Threshold (Beer):
Perceived Threshold: 10-150 ppb Depends on amount of flavor in beer
Flavor: Cooked corn, creamed corn
Aroma: Same - highly volatile
Source: Precursor in malt (SMM), hops (minor)
 
But remember that heat is what causes wort to produce DMS. Taht's why rapidly cooling the wort below 150F is so important. 150-212F is where DMS production happens.

So when you boil the extract, it could produce DMS again, especially if the extract is based heavily on Pilsner malt.

I agree with this guy. Lid off even with extract.

With a full boil you will need to start with MORE THAN 5 gallons so that after the loss to evaporation while boiling you end up with the proper volume of wort. I aim to have more then 5 gallons at the end of the boil because some beer is lost when racking to the keg.

I always start with 6 gallons of water + extracts. This boils down to 5+ gallons. I always have just the right amount to fill a 5 gallon keg. :)
 
I brew outside, or if its raining or windy, in my garage with the door open, so i leave the lid on till i get to boiling then put the lid half on half off to let out the nasties but help prevent anything from falling in, leaves pine needles, bugs etc... just my 2 pesos

Try using a grease splatter screen. They are made for covering a fry pot to keep the oil from spitting at you but make a perfect UFO guard for an otherwise open brew pot. My wife turned me on to this. You can get them at any kitchen specialty shop.
 
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