boiling wort

ok i have another rookie question...

my instructions say to boil two gallons of water then remove from heat stir in the ingrediants untill all disolved (except the finishing hops) then bring back to a boil for 60 minutes and in the last minute add the finishing hops.

Should I cover the pot when its boiling with the ingrediants?
Thanks!

I think I remember somebody else answering that question a while back. I think the lid stays off. Something to do with the boiling off of a certain something...or something like that.

Boil with it off, you are asking for a boil over with the lid on.

You can lid it until it comes to a boil though...like pasta.

You want to boil with the lid off. First off put the lid on and you guarantee a boil over. Second certain undesirable compounds are released during the boil and you want them to leave with the steam.

RichBrewer said:

....certain undesirable compounds are released during the boil and you want them to leave with the steam.

Click to expand...

That was what I was talking about.

from how to brew by john palmer:

"Covering the pot with the lid can help with heat retention and help you achieve your boil, but it can also lead to trouble. Murphy's Law has its own brewing corollary: "If it can boil over, it will boil over." Covering the pot and turning your back on it is the quickest way to achieve a boilover. If you cover the pot, watch it like a hawk.

Once you achieve a boil, only partially cover the pot, if at all. Why? Because in wort there are sulfur compounds that evolve and boil off. If they aren't removed during the boil, the can form dimethyl sulfide which contributes a cooked cabbage or corn-like flavor to the beer. If the cover is left on the pot, or left on such that the condensate from the lid can drip back in, then these flavors will have a much greater chance of showing up in the finished beer."

http://www.howtobrew.com/section1/chapter7-2.html