From Siebel...."First wort hops are used to break the surface tension of the wort, reducing the amount of hot break early on in the boil. Lessening, the chance of boil over. Thus, the brewer can fill the boiler with a higher volume of wort.".... "When FW Hops are added to the kettle. Hops that are added later, for bittering and flavoring, will contribute a smoother, rounded, bitterness and flavor, to the final product. When FW hops are used. The later additions of hops, will not need to overcome hot break remaining in suspension.".. "Since, the amount of hops used for FWH are minute. The bittering attributes are not considered. Nor, will a roughness be perceived from their use, when wort is boiled for longer periods."... "When wort is drawn from a decoction. Usually, two to five percent of the amount of bittering hops are added to the kettle, once, the bottom of the kettle is covered with wort. When the wort is drawn from an infusion. Usually, five to fifteen percent are added to the kettle. The wort drawn from the decoction method, requires a lesser amount of FW hops, than, wort drawn from an infusion. Due, to the greatly reduced amount of protein gum and starch carried over to the boil kettle." There are several pages about it in Siebel's book. Except, for improving the hops added later in the boil and the extra amount of wort that can be ran into the boiler. Nowhere, does it indicate FW Hops are used for bittering. It's a part of the brewing process that has been misconscrued. FWIW about FWH.....EIEIO...