aroma hops?

Are you supposed to leave the aroma hops or hop pellets (in a muslin bag) IN the fermenter while the beer is fermenting?

No, they go in the boil towards the end (5 - 0 minutes).
I haven't run across a recipe (although I'm certain they exist), that calls for hopping in the fermenter.
Dry hopping is normally done in the clearing tank.

Not trying to hijack the thread but my question runs along the hops idea anyway. What's the difference between bittering hops and finishing hops? I understand boiling the bittering hops for 55 minutes to get them well incorporated in the wort but why only five minutes for the finishing? Couldn't you simply dissolve the finishing pellets in hot water and add them to the primary? What would this do to the finished product?

Ah so that would explain the flavor of my first brew--TOO hoppy! Well, that makes sense and now I know what to do in the future.

Does the strong hoppy flavor mellow over time? If so, how long could it take? Thanks!

Hops have dozens of aromatic oils in addition to the resins that contain the bittering agents. The amount of time they boil determines what components are driven off and what is left in the wort. Any hops can be used at any time in the process, but some are better for bittering because they have a lot of the bittering resins.

Hop aroma mellows, generally a month or two will do it.