Pellet Hops vs Whole Leaf Hops
Whole hops (sometimes called "leaf hops" or "raw hops") are the whole dried cone flowers of the female hop plant. Pellet hops are produced by grinding up the whole hop cones and pressing them into pellets. When used for bittering, pellet hops have a higher extraction efficiency by weight than whole hops (about 10% more) - e.g. one ounce of pellet hops will yield about 10% more IBUs than one ounce of the same hop variety in whole form, and give the brewer a bit more bitterness.
Due to the grinding and compression of the hop pellets they tend to be a more stable product and less subject to oxidizing than whole hops. This is a big reason pellet hops are often used in commercial brewing and are more readily available on a homebrew scale. Whole hops are often used in dry hopping beer as they are easier to remove from the beer and may give a slightly fresher aroma than pellet hops, which lose some of the flower's essential oils during the pelletization process. Whole Leaf Hops do take up more space in the fermenter. The difference in hop flavor is slight, if any, and pellet hops also work quite well in dry hopping situations.
Want to plant your own hops? Check out our step-by-step guide to growing your own hops!