FWH Questions
 

I want to make a Bitter with FWH which I have never done.
I'm making a 10 gallon batch with a 90 min. boil.
My questions are,
1-When should I add hops (usually a 80 min. fly sparge)
2- Will a 90 min. boil have adverse affects?
Thanks.

I would add them as you are lautering. I batch sparge personally and I have always added the hops to my kettle and collected my wort. I have done 90 and 60 minute boils with FWH and I haven't noticed any negative effects.

The long sparge is my only question. Considering it is FWH I would say put them in the kettle as you start the lauter process.

I put them in the kettle before sparging. My sparge is usually about half as long as yours, but I boil 90 minutes every time and no problem. Sitting in the wort as you sparge won't cause any trouble. As they say, relax, etc.

I don't fly sparge (I batch sparge), but I FWH by placing the hops in the kettle before my first runnings. I use beersmith to help with the IBU calculations. I typically do FWH, 30-20 minute additions and if it's a hoppy beer a 15-0 minute additions.

I fly sparge and add the hops to my dry boil kettle. I've done 60 and 90min boils with FWHs and the results have been good in both cases. I almost always FWH at least some of my bittering hops nowadays, usually all of them. I perceive a better, smoother bitterness, but it's not scientific. Could just be me expecting smoother bitterness so I think I taste it. It's certainly not hurting anything, though.