Dry Hopping: Adding Bright Hop Character
Brewer: Michael Pearson, Daredevil Brewing Company in Speedway, Indiana
The main challenges with dry hopping are to have good sanitary processes and to minimize oxygen pickup. A spray bottle of StarSan and disposable latex gloves are your best friends. The combination of alcohol and low pH in beer with the antibacterial acids from hops make contamination post-fermentation unlikely when using good sanitary practices.
For novices, I would advise adding dry hops toward the end of fermentation when there are still some slow bubbles in the airlock. This assures oxygen rejection when pellet hops are added. Advanced homebrewers can add pellet hops to a sanitized carboy, purge it with CO2, and then transfer the nearly complete fermentation for secondary conditioning. It’s also okay to rock the dry hopped carboy occasionally to stir up the hops and beer too.
For the adventurous, hops added during active ale fermentations can be very impactful due to circulation of the hops, warm temperatures that favor oil extraction, and biotransformation of hop oils. This technique is for the more experienced brewer that knows their equipment and process. Warning though, adding hop pellets to an active fermentation can release a lot of CO2, leading to a beer gusher.
Traditional dry hop additions post-fermentation tend to peak in 24–48 hours for oil extraction. Longer rests don’t add more flavor/aroma, but they do allow the beer to drop more clear, which leads to the impression of brighter flavor and aroma.
Hopping rates will matter most when a brewer has minimal oxygen pickup in their processes. Work on a great dry hopped pale ale first. When that’s perfected, those processes will carry forward to everything else. There are no limits once oxygen pickup is minimized. We dry hop our small batch, very hop-forward IPAs at 4–8 lbs./bbl (2–4 oz./gal or 15–30 g/L) with a lot of success.
Any beer style can be dry hopped. The key is how the flavor, aroma, and overall hop intensity pair with the hop, malt, and fermentation character already in the beer. It’s an issue of balance. I cook a lot and often use cooking as a way to educate less experienced brewers. Dry hops are a “season to taste” step. It’s up to the brewer to determine subtle or aggressive based on their intent.
Before I use a hop at commercial scale that’s new to me I’ll dry hop a test 1⁄2 bbl batch of a beer very aggressively to get as much aroma and flavor as possible. While we can use sensory evaluation for whole cones and pellets, it’s always more informative to put them in beer to mimic the dry hopping process. At the homebrew scale this could be done with a CO2-purged Erlenmeyer flask or mason jar. The best aroma/flavor peaks within 24–48 hours. This is a quick way to evaluate a new hop or hop combination before risking a full batch of homebrew on a new ingredient.
Brewer: Matt Cole, Fat Heads Brewery in Middleburg Heights, Ohio
Maximizing dry hopping plays an important part of the flavor and aroma of your hop-forward beer. Three critical steps to optimize dry hop flavor and aroma are: Temperature, time, and surface area exposure. Warmer temperatures between 60 to 70 °F (16 to 21 °C) will help maximize the aroma and flavor of your beer. It is common to reduce the temperatures slightly for the precipitation and settling of yeast before dry hopping. Avoid dry hopping at cold temperatures as they can lead to raw, grassy, and vegetative flavors to your beer. For contact time, shorter or longer periods of dry hopping will underutilize the hops. In our experiments we have found that it takes 7 to 9 days to fully utilize aroma. Dry hopping for just a few days can lead to an unpleasant raw hop flavor that can taste very unrefined. For surface area, hops sitting idle at the bottom of the fermentation vessel are not being fully utilized. So rouse your hops to get them back in suspension.
Another method that can reduce dissolved oxygen and greatly increase hop flavor and aroma is primary fermentation dry hopping. Add a round of dry hops 2⁄3 of the way through fermentation so that the convection of the ferment helps rouse the hops, helping release their flavor and aroma. Be sure to use a larger vessel when using this method as the hops can create foaming and a gushing reaction.
For hop varieties, the classic 4 C hops (Cascade, Centennial, Columbus, Chinook) in any combination work great. A few other varietals that give big tropical character are Simcoe®, Citra®, Mosaic®, EkuanotTM, GalaxyTM, and Nelson Sauvin. My personal favorite combination is Simcoe®, Mosaic®, Citra®, and Chinook. A good starting point for an American IPA dry hopping is around 1 oz. per gallon (7.4 g/L) and 1.75 oz. per gallon (13.1 g/L) for a double IPA. Adjust accordingly to the style, your system, and your desired flavor.
More is not always better. Over hopping can lead to vegetative flavors and aromas. Finally, don’t use hops that don’t have have a pleasant aroma.
