I have used a Co2 hop extract of Marinka and Lublin. Our supplier imported pellets and extract from Poland. I found it best used for bittering as it didn't impart the aromatic properties that pellets or whole leaf would. So i would avoid using it on a hop forward beer, like a pale or an IPA.
We used about 20-60 grams for a bittering addition on a 10bbl system, depending on the beer style. It did the job, and it did not go bad, or take up much space.
Jeff Byrne (aka jephro)
11 year pro craft brewer available for hire...
Puyallup, Wa - for now