I've been using pellet hops in hop bags in the boil since the beginning of my brewing habit. I first purchased the medium sized nylon type from MoreBeer and soon discovered how limiting the size was. After the boil, the hops had expanded into a fist tight ball that pressed against the constraints of the bag. No me gusta! So, I started using 5gal. paint strainer bags a couple years ago to give the hops some more room to be exposed to the hot wort. My thinking and hope was that I could achieve a higher degree of flavor and aroma. You can go here to see other ideas or here to see my 'hop spider' solution . But there were problems with using these techniques, mainly that even with the larger bags the expanding vegetative mass appeared to seal off the flow of wort through the hops. I haven't done any studies to prove this so don't hold me to this theory but just from the looks of it I'd say I'm not getting my fair share of the available goodness from the hops....
A Homebrewing Blog that chronicles my brewing adventures, trials and successes from Santa Cruz, Ca. to San Miguel De Allende, and Patzcuaro Mexico.