Wet Hopped Beers

Definition

Wet hopping is the use of fresh hops that a have recently been picked. Hops are not hard to grow in most areas of the US. They are grown from a rhizome, which is a root-like 'stick' that is planted. Wet hopping is a fun and rewarding way of using home-grown ingredients in your beer.
Because of the moisture content of fresh hops as compared to dried pellets, plugs, or whole hops you might get from a manufacturer, one ounce of fresh hops will impart much less bitterness than a comparable mass of the same variety that has been dried.

How Much to Use

An equivalent weight of dried hops imparts about six times the IBU of a fresh, non-dried hop of the same variety. So, let's say you have grown some cascade hops in your back yard, they seem ready, and you are ready to throw some in your Pale Ale. First thing you will need to know is the AAU% of your hop. Well, that's not easy without lab analysis. No worry, just take the medium range of the hop variety to get an idea. Since cascade is in the 4 to 8% range generally, we will take the average ((4+8)/2=6). Ok, so 6% is roughly what we will say our AAU is. Now, divide this number by six (because the ratio of fresh/dried AAU is 6:1). That gets us down to 1 AAU%.
You can now plug this value into a New Hop Variety in your handy BeerSmith program called Fresh Cascade, and factor these into your recipe.
One note about wet hops - they seem to impart a 'green' flavor into the beer - so go easy. My recommendation is to use dried hops for the bittering and add your nice, fresh wet hops in as an aroma addition.
Another note - if you're reall worried about it, wet hops will decrease your gravity a little bit due to all the moisture. Probably a point or two a most. Not a big deal in my book, but worth noting.