this is an email i received last month from BS for anyone wants to read it and missed it.
I have FW hopped several times and found that it made little difference but with the amounts of hops I use anything subtle is probly hard to pick up.
BeerSmith Home Brewing
First Wort Hopping your Beer
Brewing beer with first wort hops (FWH) is a method I have used extensively for beer brewing over the last few years to improve the character of many recipes. First wort hopping produces complex bitterness and aroma that is both smooth and pleasing to the pallet. The method has become quite popular with homebrewers and microbreweries over the last 10 years due to the pleasant and complex flavor produced.
FWH involves adding a portion of the hops to the boiler at the very beginning of the sparging process, allowing these hops to steep as the sparging completes and remaining in the kettle throughout the boil. Add the hops to the boiler as soon as you have finished recirculating the first runnings.
First Wort Hopping is not a new method, but is in fact an old one from Germany that was largely forgotten until Priess, Neuremburg and Mitter published an article on it in 1995 (Brauwelt International, Vol IV, p 308). The method was originally used by brewers at the beginning of the century to enhance bitterness rather than overall flavor. Adding hops to the wort early in the sparging process reduced the Ph of the mash, which enhanced isomerization of later hop additions, increasing overall hop utilization during the boil.
Sources vary, but most testing indicates that first wort hopping will increase the number of International Bitterness Units (IBUs) by as much as 10%. Given the hop shortage I wrote about earlier, increased utilization is an added bonus. However, taste perception is different. In blind taste testing across a number of articles, the overall flavor of first wort hops is perceived as smoother, less sharp, and had a more pleasing aroma. Hop bitterness was perceived as harmonic and uniformly bitter. In blind taste tests, the FWH were preferred by 11 of 12 test subjects. (Ref: FWH, Brewery.org)
First wort hopping can be used both by all grain and partial mash brewers. As the FWH method originated in Germany, it has most often been associated with Pilsner beers, but other beer styles with complex hop flavor could benefit. Aromatic, noble and other low alpha hops are recommended, as high alpha hops may provide too sharp of an increase in bitterness.
The amount to hops to use varies. Most sources recommend using 30% of the overall hop schedule and moving it to FWH. Other sources recommend taking aromatic hops from the end of the boil and moving it forward to use as FWH. I have even experimented on my Wit beer with using FWH exclusively and had good results. My limited experience indicates that if you are looking for a smooth pilsner style hoppiness, moving a portion (30%) of the finishing hops forward is appropriate. If you want the hops to blend into the background of the beer for relatively low hop rates, you can consider moving a larger portion of your hop schedule forward. FWH in general will produce a more complex, blended hop flavor.
Calculating the FWH numerically is quite simple. In most cases an adjustment (10%) is added to the calculated bitterness in IBUs to account for the higher utilization of FWH methods. For
BeerSmith users, there is a checkbox for first wort hops available as you add each hop addition, and BeerSmith will adjust the IBU calculation to account for the higher utilization. Despite the slightly higher IBUs of FWH, most authors do not recommend reducing the overall hop rate to compensate.
Overall, I have been very pleased with the effect first wort hopping has had on my beers. I have taken to using it on a larger variety of beer styles recently with good results. FWH seems to produce a more complex, pleasing and harmonic hop flavor and aroma that beer drinkers find pleasing.