boil with lid on or off?

RonPaul · 11-22-2011, 11:06 PM

I have heard people say that they don't brew with the lid on their brew kettle... Is there a reason for this?

TarheelBrew13 · 11-22-2011, 11:08 PM

During the boil, the lid should be off. This is because you want to reduce the liquor volume. However, I do leave the lid on while bringing the liquor to boiling temp.

**jeepinjeepin** · 11-22-2011, 11:10 PM

When you boil you are driving off DMS precursors(bad flavors). If you have a lid on it condenses under the lid and drip back into the wort.

maffewl · 11-22-2011, 11:11 PM

Quote:

Originally Posted by jeepinjeepin

When you boil you are driving off DMS precursors(bad flavors). If you have a lid on it condenses under the lid and drip back into the wort.

This

**passedpawn** · 11-22-2011, 11:12 PM

Holy Cow, Ron Paul!

Leave the top off. Some nasty compounds leave the wort during the boil. If you leave the top on, they will condense and go right back into the beer. DMS is the big one. You can end up with a beer that tastes strongly of creamed corn. I can tell you from first-hand experience (not beer tho) it is nasty and undrinkable.

Leave the top off. Oh, good luck in tonights debate.

**jeepinjeepin** · 11-22-2011, 11:14 PM

Quote:

Originally Posted by TarheelBrew13

During the boil, the lid should be off. This is because you want to reduce the liquor volume. However, I do leave the lid on while bringing the liquor to boiling temp.

This too.

You are doing several things during the boil.
1. Sanitization
2. Isomerization of hop alpha acids
3. Concentrating wort sugars via boil off
4. Driving of volatiles that cause off flavors
5. I'm sure there are others I am missing.

3 and 4 have to have the lid off.