Got it look up and got some good info on in
QUOTE FOR bodensatz
Dry hopping is the practice of putting hops directly into the fermentor or keg. The practice yields an aroma and spicey flavour that is similar to late-hopping in the kettle, only more pronounced. It has been our experience that non-beer-geeks (i.e. your average Joe who doesn't know Budweiser from Buddy Holly) absolutely love dry-hopped beer.
There really isn't a whole lot involved in doing this. Normally you want to add the hops to the secondary fermentor, because if you add it during heavy fermentation the excaping CO2 will scrub out most of the aromatics that you put the hops in for in the first place. So it would be rather counter-productive. Just take them out of the package and throw them in. That's it.
We've found that the best types of hops for dry-hopping are the noble hops, or other low alpha hops which have good flavour and aromic properties. You probably wouldn't want to use any of the high-alpha hops which can have fairly abrubt and abbrasive aromatic characteristics. We also prefer the use of whole or plug hops for dry-hopping, because they tend to float on the top which helps protect your beer from infection. Though we do know that lots of people use pellets with great success. We've found that you need 1 ounce or more to get a really nice hoppy flavour and aroma in the beer. Leave them in the secondary for a good couple of weeks. When it comes time to siphon to your bottling bucket, putting a copper pot scrubber over the end of your J-tube will help keep the hops from clogging up the works during syphoning.
If you keg your beer, you can toss the dry hops right into the keg. If you do this we recommend affixing a copper pot scrubber to the end of the long dip-tube, to help keep the hops from getting sucked up into the dispensing tubes. Leaf hops tend to float on top, so you aren't going to have a problem with those until the keg starts to get empty. Using the pot scrubber helps a great deal we've found, no matter what type of hops you use, or how full the keg is.
Some people recommend steaming your hops first before dry-hopping with them. They do this out of fear of infection. The fact of the matter is, however, that hops are naturally antiseptic. In fact, one of their key functions in beer is as a preservative. As such we feel that this risk is highly overstated, and we continue to just throw the hops in with no ill effects. In fact, often we'll dry-hop a beer with leaf hops if we think it will be sitting around in the secondary for an extended period. The hops float on the top and help keep the nasties out. At the time of this writing we've got a Pale Ale in the secondary at room temperature now for over 7 months (boy, are we lazy). The dry hops are floating on top, protecting it from an infection.