It’s extremely common for most homebrewers to apply the wrong hopping technique to their style of beer. Knowing which technique to use for a particular style or desired flavor profile is part science, part art form, and part reading this blog post, “Hopping Your Homebrew.”
Mash hopping is seldom used today because it requires a fairly large amount of hops and adds very little in direct flavor.
First Wort Hops
First wort hops are hops added to the boil pot at the very start of the lautering process. Unlike mash hops, first wort hops remain in the boiler during the boil and therefore do contribute bitterness to the wort.
Late Hop Additions
Hops added in the last 5-15 minutes of the boil are called late hop additions. These hops are usually not added for bittering, though they do contribute a small amount of bitterness to the beer. The main purpose for late hop additions is to add aroma and aromatic hop oils to your beer.
In addition to bittering compounds, hop cones from “aromatic” hop varieties contain volatile hop oils that provide the strong flowery aromatic flavor and scent desirable in many hoppy beer styles. Unfortunately most of these compounds boil off within 10-20 minutes of adding the hops.
Late hop additions should always use “aromatic” hop varieties, and should be done within the last 10 minutes of the boil to preserve as many aromatic oils as possible.
The Hop Back
A hop back is a device containing hops used inline between the boiler and chiller to infuse fragile hop oils and aroma directly into the hot wort before it is cooled and transferred to the fermenter. While a hop back does not add any significant bitterness to the beer, it can add great aroma to your finished beer.
Dry hopping is the addition of hops after the beer has fermented. Hops are typically added in the secondary fermenter or keg and left for a period of several days to several weeks. Dry hopping is used to add a hoppy aroma to the beer, as no bitterness is added with this method.