How do you use hops in beer making?
Ive used it green as a tea added to wort.
Has anyone ever lightly roasted hops. Is it steeped in the mash then filtered or added cold afterwards to the fermenter?
Hops are used a couple of ways in beer making ... one way is to boil the hops for a long (15 minutes to an hour or so) time to release compounds that produce the bitter taste in a beer and add to the preservative qualities. The other way is to add hops at the end of a boil or "dry hopped" into the primary or secondary fermenter to add aroma and the lighter hop flavors that are found the volatile oils (those that are boiled off during fermentation).
I've never tried making a tea out of the hops, I just throw them in and get going. You can use both whole leaf hops and processed, pelleted, hops towards the same result. Depending on when they are added, they are left behind during racking from the primary to the secondary or the racking just prior to bottling - all except using whole hops seem to drop to the bottom very easily so racking isn't difficult; for whole hops, they have a tendency to float so I just cover the end of the racking tube with a piece of cheesecloth and it seems to do the trick.
I've never tried to roast hops ... I guess it'd work with bittering hops but I'd be concerned about losing aroma otherwise and you'd have to be careful when roasting fresh ones not to catch them on fire since they are so dry.