This week I check out chilly, brief period dry hopping which appears counter-intuitive however has been proven to have its benefits for sure beers.
Scott Janish was the primary one to point out chilly dry hopping to me throughout a podcast in 2021 (Dialogue begins round 42 min). He subsequently revealed a brief article on his weblog right here making the case for chilly dry hopping with a comparatively brief period.
From a strict science perspective, the principle goal of dry hopping is to attempt to get comparatively insoluble fragrant compounds into the beer. I’ve mentioned many instances that the explanation these oils are fragrant is that they don’t like to remain within the beer. Sometimes it’s simpler to get a comparatively insoluble compound into answer by making use of both time or temperature or each.
So if we have a look at whirlpool hopping, as an illustration, we add hops at a comparatively excessive temperature for a brief period of time (maybe 10-40 minutes) in an effort to get a few of the fragrant oils into answer. In distinction, dry hopping is completed at comparatively low fermentation or storage temperatures, however the hops are left involved for a for much longer time period – often 1-3 days and generally longer.
So it appears counterintuitive to assume that dry hopping for a comparatively brief time period at even colder temperatures goes to assist fragrant oils get into the completed beer. Nonetheless, the concept caught in my head so I made a decision to dive deeper.
The Case for Shorter Dry Hop Occasions and Agitation
Lets first check out the optimum contact time for dry hopping. After I first began brewing we frequently dry hopped for every week or extra and even used a way referred to as keg hopping the place you actually left the hops within the keg till the beer was gone. Nonetheless, the IPA revolution modified all of that, as brewers began to make use of excessive ranges of dry hops for types like Hazy IPAs, and we additionally gained a greater understanding of dry hops.
For dry hopping, the aim is to get fragrant hop oils into the beer, however keep away from extra undesirable vegetal flavors. Brewers have discovered that many hop varieties are liable to creating vegetal, garden mower or contemporary lower grass flavors within the completed beer if dry hopped too lengthy. So how a lot is sufficient?
Scott Janish notes in his article above that Wolf, Qian and Shellhammer revealed a examine the place they checked out fragrant compounds after dry hopping on the 1, 4 and seven day timeframes. They discovered that some oils like myrcene and linalool, peak focus was reached inside 24 hours and in reality dropped barely at 7 days. There’s some proof that the majority of the extraction takes place in a matter of hours. Ref: (2012, The Impact of Pellet Processing and Publicity Time on Dry Aroma Extraction, ACS Symposium)
They did one other take a look at however this time added agitation by dry hopping on a shaker desk to maximise extraction. On this case the linalool peaked in solely 4 hours. On account of this work, Scott now used a lot shorter contact instances and has added agitation to his dry hop routine.
One other examine (Reglitz, Okay., N. L., S. H., & M. S. (2018). On the Habits of the Essential Hop Odorant 4-Mercapto-4methylpentan-2-one (4MMP) throughout Dry Hopping and through Storage of Dry Hopped Beer. BrewingScience,71, 96-99) discovered that thiols additionally could possibly be extracted shortly, and certainly peaked inside two days of dry hopping.
If you wish to be taught extra , Scott has quite a lot of sources listed right here of research that assist the case for brief dry hop instances. Among the many advantages are good hop oil extraction, higher head retention, diminished hop creep and higher Hazy IPA stability utilizing a contact time of as little as 24-72 hours.
Chilly Dry Hopping and Polyphenols
What about dry hop temperature? Scott cites analysis that discovered that dry hopping at a decrease temperature reduces the polyphenol concentrations by an element of two or extra by dry hopping at 39 F (4 C) versus 66 F (19C). These polyphenols contributes to the aggressive bitterness we confer with as “hop chew” current in lots of Hazy IPAs. Time additionally performed a task, with the extent of polyphenols peaking at about 3 days and remaining steady by way of 14 days. So lowering the temperature and get in touch with time may end up in much less hop chew. Ref: (Oladokun, O., James, S., Cowley, T., Good, Okay., Hort, J., & Prepare dinner, D. (2017). Dry-Hopping: the Results of Temperature and Hop Selection on the Bittering Profiles and Properties of Resultant Beers. BrewingScience, 70, 187-196.)
There’s additionally proof that hop creep is diminished by reducing dry hop temperatures and get in touch with time, and as surprisingly the decrease temperatures don’t decelerate the absorption of hop oils by very a lot.
Optimum Dry Hop Time and Temperature
So what’s the optimum dry hop time and temperature? As at all times it’s a stability of tradeoffs. For instance an Hazy IPA with excessive ranges of dry hops would possibly profit from a really brief contact time of 1-2 days and low temperature (maybe 39 F/4C) to cut back hop chew, hop creep and nonetheless retain a lot of the oil and thiol extraction. You additionally would possibly wish to apply agitation to the fermenter or rouse the hops each few hours to reinforce extraction and shorten the time even additional.
A extra calmly hopped beer the place hop chew and hop creep is just not as massive a threat is perhaps OK with an extended 3 day contact time and barely increased temperatures. For these interested by extra particulars, I extremely suggest Scott Janish’s detailed article right here.
I hope you loved this week’s article on chilly dry hopping. Thanks for becoming a member of me this week on the BeersSmith weblog – please subscribe to the publication or take heed to my video podcast for extra nice materials on homebrewing.
