When to Use Different Hopping Techniques in Beer

This week I take a look at the major hop techniques, and provide a perspective on which hop techniques are best used in different situations.

Hop Addition Techniques

While there are subtle variants of each particular technique, there are four major hop additions you can use when brewing beer.

• Boil Hops: This is the oldest and most popular hop technique. Hops in the boil is the primary method used to add bitterness to your beer to balance out sweetness from the malt, though boil hops serve a wide variety of secondary function including acting as an anti-bacterial preservative and aiding in head retention. Variations here mainly include using multiple additions as well as the timing of these additions, though shorter boil additions have recently been decreased in favor of whirlpool or dry hop additions.
• Whirlpool Hopping: Adding hops shortly after the boil has completed but while the wort is still hot has become a very popular technique. Because most delicate hop aroma oils are very volatile, they are lost in the boil. However at temperatures slightly below boiling they will not boil off. In addition the higher temperature aids in getting the relatively insoluble hop oils into the hot wort. Also whirlpool hopping does add some bitterness which you can calculate in BeerSmith.
• Dry Hopping: This is another very old technique. Early on brewers realized that adding hops to fermented wort imparted a hoppy fresh aroma and flavor to the beer. In this case, we are preserving the subtle aromatic hop oils by infusing them at low temperature over a longer time period. Recent studies have found somewhere around 24 to 72 hours of contact time gives you maximum impact with minimal off flavors. Dry hopping does impart a perception of bitterness to the beer though it is not directly from isomerized alpha acids, but rather from aromatic oils and other compounds in the hops that we perceive as bitter. In the last few years brewers have moved to dry hopping at the tail end of active fermentation to enhance fruity flavors for certain IPAs, as well as cold dry hopping as variations.
• Mash Hopping: Mash hopping is also a relatively old technique. I was a longtime critic of mash hopping as it is an inefficient way to add both bitterness and also adds virtually no aroma. However, recent research indicates that mash hopping can enhance the long term stability of some beers by reducing the amount of free metals in the finished beer. Also some brewers have experimented with mash hopping to enhance thiols for fruity IPAs with some success. I summarize some of the recent results here if you are interested in mash hopping.

When To Use Each Technique

One of the key steps in beer recipe design is deciding which techniques apply to the particular style of beer or effect you are trying to create in a finished beer. So let us take a look at each technique in terms of when it makes the most sense:

• Boil Hops Application: The main purpose of a boil hop addition is to isomerize alpha acids, which transforms those acids into the primary bittering compound in a beer. So boil hops are applicable in just about every beer style, as they lay down the foundation of bitterness needed to offset the sweetness of the malt. In fact only a small number of beers are made without boil hops. For most beers I recommend a single long boil addition for bittering as this is the most efficient use of your hops, though you can of course use a hop blend if you want to get a mix of hop flavors. A hop addition around 60 minutes will give you the best balance of maximum bitterness without off flavors for efficient hop use.
• Whirlpool Hopping: Whirlpool hopping is used in beer styles where you want to enhance the fresh hoppy aroma in the finished beer by infusing aromatic hop oils. This includes popular styles like Pale Ales, IPAs, Hazy IPAs and basically any hoppy beer though it can be used even with moderately hoppy ales like milds and English Pale Ale. This technique is most often used in combination with dry hopping depending on the aroma you are trying to achieve as different aromatic hop oils have differing levels of survivability for whirlpool and dry hopping. See this interesting article on hop survivability which details which varieties do best, along with this one on aromatic oils to understand which hop oils correspond to which aromas.
• Dry Hopping: Dry hopping is another method to infuse aromatic oils into the finished beer. It was traditionally done for many English styles like Milds, Bitters, and Pale Ales, but is now used on a wide variety of beer styles. It is also heavily used in Hazy and New England IPA styles where often huge doses of dry hops are applied for a unique aromatic finish. As mentioned at the bottom of the whirlpool section above, certain hop oils and varieties survive better in the finished beer when using dry hopping. Timing and length of dry hopping varies, though a contact time of 24-72 hours is considered best. For timing, many fruity flavored IPAs and Hazy IPAs will use dry hop additions near the end of the active fermention which can biotransform free thiols and oils like geraniol giving a tropical finish. However, most dry hop additions are done after fermentation has concluded, and some IPAs are double or even triple dry hopped with multiple infusions. I don’t recommend dry hopping a single addition for a long time as it can lead to lawnmower off flavors. Also you need to be aware of dry hop creep which can occur in beers with very high dry hop rates.
• Mash Hopping: As my article on mash hopping mentions, mash hopping might be appropriate if you have a commercial beer or homebrew you may store on the shelf for an extended period as it can aid in shelf stability. Also some brewers have had good results combining mash hopping with other thiol boosting techniques like dry hopping during fermentation, thiol boosting yeasts and thiol additives to generate fruity flavors in a finished beer. Outside of that, most beer styles do not need a mash hop addition.

I hope you enjoyed this week’s article on hop techniques! Thanks for joining me on the BeerSmith Home Brewing Blog. If you want to take the guesswork out of brewing, please try my BeerSmith recipe software from BeerSmith.com. Be sure to sign up for my newsletter or my podcast (also on itune and youtube) for more great tips on homebrewing.