After the completion of primary fermenting, you then add hops back to the beer for it to steep. This is called dry-hopping.
One of the most fundamental ways to dry-hop your beer is to simply siphon it from the fermenter into another fermenter and then add hops. Through dry-hopping, the beer enhances its aroma. The question is, for how long should you dry-hop your beer?
24 hours of dry-hopping can already add a good amount of aroma. This will be more pronounced after 48-72 hours. After that, the aroma being added gets little and little. Leave it for several weeks, and the beer develops a slightly odd flavor. This should be avoided, so make sure to watch out for this. A good amount of time is during the entire second fermentation.
There are several variations of dry-hopping. The French press, albeit not the most ideal, is a variation that is a quick way to determine what aroma compounds work best. Keg hopping, on the other hand, is when hops are placed in bags, making them look like tea bags, and then added directly to the keg.
Lastly, the Randall is a device that you hook to your tap lines, enabling you to push your beer into your hops.