Lid on or lid off?

As an extract brewer I have been boiling the wort with the lid off of my kettle.
However, I was just reading "Brew Chem 101" and Janson recommends leaving the lid on, however cracked a few inches. I'm curious, how many folks are going topless and how many go top-on?
Thanks.

I've always brewed lid-off, whether extract or all grain. The only exception was the one time I did a partial boil indoors, and that was only because I couldn't maintain a boil without the lid partially on the pot, as you described, on my stovetop.

Topless is the only way to roll. It matters less with extract brews however when you go all grain you need the lid off as many things you do not want in your brew boil off and escape with the evaporating liquid during the boil such as DMS.

your call man. imo, it doesnt matter at all.

Top-less all day errryday!!

Top off. But I do leave the top on to get to boil. This limits me to a 3.5 gallon boil on my stove top, which is why I don't recommend a boil kettle larger than 4 gallons unless you have an outdoor burner.

Top off to allow the VOC's an escape route. You don't want those bad boys funkifiying your brew.

off

As others have said, top off in order to release the DMS (at least on an AG boil). Glad I learned this before starting my AG campaign!

Top off. Want to make sure I get my wort down to my batch size. I feel if the lid is on you get a lot of the water back in the kettle.

When I'm brewing outside where bugs and what-not can fall in I do a partial cover to allow the VOCs to escape. When indoors, topless.

Do an experiment. Boil with the lid on, occasionally remove the lid and collect the condensate that forms on the bottom. Taste what you've collected and decide for yourself. I think it tastes nasty, so I boil lidless!

bergy said:

When I'm brewing outside where bugs and what-not can fall in I do a partial cover to allow the VOCs to escape. When indoors, topless.

Click to expand...

Bugs tend to avoid the heat just like when you BBQ, just avoid brewing under a tree.

Topless to avoid any DMS...

With extract it doesn't matter since everything is taken care of during the manufacturing process.. all grain is always top off...
Step 4...
http://***********/stories/techniques/article/indices/30-extract-brewing/1106-making-malt-extract

Edit: this is kinda contradicting saying it can create more DMS when held at a hot temp when the DMS is already removed..
I still see it as a might and not a definitely creating more DMS but would not worry!!


Carmelization and Volitization:

Brewing- grade extract has already undergone a kettle boil and extensive volatilization. Beneficial colors and flavors have been developed from carmelization and Maillard reactions in the kettle boil. Any volatile off aroma or flavors from the grain or DMS precursors have been removed. If the extract is diluted to wort and held at boiling temperatures without proper additional volatilization, additional precursors can be generated. In general, worts from malt extract do not need to be boiled to remove DMS precursors. However, if they are boiled, the boil must be vigorous enough to remove these precursors as more are created when wort is held hot.

Nice find!