Author: Greg Foster
I’ve always been interested in the differences between pellet and whole cone hops. Clearly both can be used successfully– Sierra Nevada makes world famous beers utilizing only whole cone hops, while the majority of commercial breweries tend to stick with pellets.
As a homebrewer with fairly easy access to pellet and whole cone hops, I use both regularly. It seems to me that most brewers’ decision whether to go with pellets or whole cone generally has to do with storage and filtering considerations, with pellet hops requiring less space to store and cone hops providing better filtration. However, for me an even more important question remained: which one makes the best beer?
| PURPOSE |
To evaluate the impact of dry hopping a split-batch of the same beer with either pellet hops or whole cone hops.
| METHOD |
I knew before getting started that an important aspect of this investigation would be finding the right hops, primarily because they are a highly variable agricultural product, meaning what one distributor offers is often completely different than what can be purchased from another distributor. To minimize these differences as much as possible, I purchased a pound each of 2014 Centennial pellet and cone hops from Hops Direct as soon as they became available. My thinking here was that sourcing the hops from a farm that grows and processes their own crop would increase the odds that both versions would be of similar quality and chemical makeup (i.e, AA%, oil levels, etc.). Moreover, I decided to stick with a single hop variety to keep things simple and not muddy the waters. Upon arrival, I gave the hops a quick smell test.
I picked up a surprisingly strong lemon aroma from these hops with some subtle yet noticeable floral notes. They smell great– pungent and delicious! The aroma from the pellet hops was significantly more subdued compared to the whole cone, which smelled much stronger, brighter, and sweeter. The differences were fairly obvious, one that I definitely was not expecting since these hops came from the same exact source. It was time to get brewing!
I settled on a Bell’s Two Hearted IPA clone based roughly on the recipe provided by scientifically minded blogger, Sean Terrill.
Two Hearted (f)Ale Recipe Details
| Batch Size | Boil Time | IBU | SRM | OG | FG | ABV |
|---|---|---|---|---|---|---|
| 8 gal | 75 min | ~54 IBU | 11 SRM | 1.079 SG | 1.013 SG | 8.6 % |
Fermentables
| Name | Amount | % |
|---|---|---|
| Domestic 2-Row | 18 lbs | 85.71 |
| Munich Light | 2.25 lbs | 10.71 |
| Crystal 40 | 12 oz | 3.57 |
Hops
| Name | Amount | Time | Use | Form | Alpha % |
|---|---|---|---|---|---|
| Centennial | 38 g | 75 min | Boil | Pellet | 8.9 |
| Centennial | 28 g | 20 min | Boil | Pellet | 8.9 |
| Centennial | 28 g | 10 min | Boil | Pellet | 8.9 |
| Centennial | 50 g | F/O – 20 min stand at 202°F | Steep | Pellet | 8.9 |
| Centennial | 28 g | 10 min stand, added at 180°F | Steep | Pellet | 8.9 |
| Centennial | 60 g/keg | Dry Hop – 1 week | Aroma | Pellet/Cone | 8.9 |
Yeast
| Name | Lab | Attenuation | Temperature |
|---|---|---|---|
| SafAle US-04 English Ale (x 2) | Fermentis | 72% – 75% | 59°F – 75°F |
This ended up becoming one of those lovely brew days where everything went perfectly… wrong. I really wanted to nail this recipe but it seemed the beer gods had it out for me. I undershot my mash temp by 4°F, milled my grain fine enough to reduce the recirculating wort to a trickle, clogged my kettle hop filter while recirulating during the hop stand, spilled a bunch of wort, burnt my arm, overshot my OG by .017 points… I’m venting. It was at this point I poured myself a nice big glass of my version of Kate the Great Imperial Stout. Things began to look up.
I eventually chilled the wort to about 85°F, transferred it to my corny keg fermentation vessel, and placed it in my chest freezer to finish chilling. It reached my target pitching temp a couple hours later, at which point I proceeded to oxygenate the wort, pitch my yeast, then turn on Netflix in an attempt to forget what had just happened.
The beer was fully attenuated by the following week, dropping to the expected FG of about 1.013.
It was finally time to start the exBEERiment! The finished beer would be evenly split between 2 “secondary” kegs and dry hopped separately. I wanted the hops to float freely in the keg and not be hindered by a hop bag, as I figured this would provide the best conditions for the hop oils to mix with the beer and ultimately optimize aroma. I repurposed two stainless mesh dry hoppers I had lying around to serve as keg hop blockers by drilling a hole in the top and attaching them to the end of each dip tube.
After sanitizing each keg, I measured out 60 grams each of cone and pellet hops, adding them to their respective kegs.
I then repeatedly pressurized and purged the empty kegs, a process intended to rid the keg of all oxygen, which I believe is crucial for IPA (xBmt?). Next, approximately 2.5 gallons of beer was transferred to each keg using a closed transfer system, which is as simple as pressurizing the primary keg then using a “jumper” to connect and push the beer to another keg.
I allowed both beers to rest on the dry hop additions at room temperature for a week, leaving them attached to the CO2 to carbonate. When the time came, I sanitized two more empty kegs and transferred the finished beer to them, putting my makeshift blockers to the test for the first time.
They worked perfect! I immediately put the beers on tap and excitedly pulled a couple test samples to compare. The pellet dry hopped beer was significantly more hazy upon first sample, while the beer dry hopped with whole cone was looking pretty good.
Both beers cleared up rather nicely a few days later and looked essentially identical by data collection time.
| RESULTS |
In August 2015, we began utilizing a 1-tailed binomial proportions test, a more appropriate and slightly more liberal statistic than the the 2-tailed test. Following this change, we reran all of our prior xBmt data to test for changes in significant results. This xBmt was identified as being significant (p=0.029) utilizing the new statistic when previously we said it had failed to achieve significance.
In all, 14 people participated on the tasting panel, all of whom were provided no information about the nature of the xBmt. Each participant received 3 samples of beer, 2 of which were dry hopped with pellets and 1 that was dry hopped with whole cone hops. The tasting panel included 3 homebrewers, 4 BJCP Certified judges, and a BJCP Provisional judge; all participants regularly enjoy drinking and evaluating craft beer.
Given the sample size, statistical significance would be achieved if 9 or more of the participants accurately distinguished the beer dry hopped with cone from the 2 dry hopped with pellets. Of the 14 people on the tasting panel, 8 (57%) correctly selected the different beer sample. From a purely statistical standpoint, this does not conclusively prove there is a strong perceptible difference between a beer dry hopped with pellets compared to one dry hopped with whole cone hops.
After making their triangle test selection, each taster was then asked about how confident they were in their selection. The responses here yielded interesting results:
– Of 2 participants indicating they were not very confident, neither were correct
– Of 6 participants indicating they were somewhat confident, 4 were correct (67%)
– Of 5 participants indicating they were very confident, 4 were correct (80%)
– Of 1 participant indicating they were absolutely certain, 0 were correct
Extrapolating from this data, we can at the very least conclude that confidence is to some degree correlated with selection accuracy, which I find to be rather interesting.
There was nearly unanimous agreement among the 8 correct participants that the beer dry hopped with whole cone hops had a fresher, stronger, sweeter, and generally more pleasing aroma compared to the beer dry hopped with pellet hops; only one person described the aroma of the beer dry hopped with whole cone as being “less hoppy.” The pellet hop beer was described as having a smoother and milder flavor, with one person saying they experienced far less hop flavor in it compared to the whole cone beer. While 5 of the 8 tasters guessed this xBmt had something to do with hops or aroma in general, none specifically mentioned hop type (pellet vs. cone) or dry hopping as being the variable investigated. In terms of taster preference, it was split right down the middle.
My impressions: You just read the results of the tasting panel survey, that there are no statistically significant differences between these two beers. Well, my initial experience couldn’t have been more different! When I first triangle tested myself (served blindly by someone else), I perceived the beers as smelling strikingly different, making the correct choice obvious. In the introduction to this article, I described the fresh whole cone hops as having a stronger, sweeter, more lemony aroma that packed a bigger punch compared to the fresh pellet hops. This is exactly what I was getting from the finished beers upon my own evaluation.
I realized something interesting while analyzing the data that may provide a potential explanation for these results. The first 4 participants evaluated the beers within days of it being racked from the dry hop keg to the serving keg. They all chose correctly. That’s right, everyone in this first trial perceived the beers as being different. At the time, this xBmt seemed like an obvious slam dunk. Then life happened and I wasn’t able to administer the evaluation for about a week, during which the beers remained untouched in the kegerator. I finally cajoled a couple more beer drinking friends into participating and was stunned to discover they both selected the wrong beer. Out of curiousity, and for science of course, I sampled the beers side by side again. To my utter surprise, and despite my obvious bias, the perceived difference was nill.
What the hell? How could that unmistakably strong hop aroma fade so quickly?
Apparently, the nuances of dry hop aroma can fade far faster than I ever expected. I went on to collect additional data for this xBmt at the Pacific Gravity Homebrew Club meeting the following week.
Again, many had difficulty choosing which beer was different, and even those who chose correctly reported the differences as being very subtle. A couple tasters noted something interesting that I had previously missed– the head on the beer dry hopped with whole cone hops dissipated slightly quicker than that of the beer dry hopped with pellets.
This was a result I had not expected and makes me wonder to what extent the additional plant matter from the whole cone hops affects head retention.
| DISCUSSION |
The question I originally posed for this xBmt was simple: which is better for dry hopping, whole cone or pellet hops. Based on the statistical data alone, it seems both contribute similar aromatic qualities when used for dry hopping. So, take your pic, it probably doesn’t matter.
However, my takeaway is slightly different. Given the fact the first few participants were easily able to distinguish between the 2 beers, I’m comfortable accepting that beers dry hopped with whole cone hops will be noticeably more intense when fresh, the intensity fading over time, eventually dropping to a level similar to that of a pellet dry hopped beer. This will definitely impact my decisions when it comes time to design recipes in the future, perhaps it will yours as well.
Thanks for taking the time to read this article, it was a ton of fun for me! Cheers to Marshall for his invaluable help, to my friends who agreed to participate, and especially to Pacific Gravity Homebrew Club for graciously contributing some great test subjects. I’ve got a ton more exBEERiments planned so keep your eyes peeled. Until next time, cheers!
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27 thoughts on “exBEERiment | Dry Hopping: Whole Cone vs. Pellet Hops In An American IPA”
Fascinating post, Greg! It’s super interesting to see that the difference was negligible after only a week. As someone who can’t keg, I’d love to see if that means that any aroma differences would be gone as soon as the bottles were carbonated and ready to drink.
Thanks, that’s a really good idea! I’ll try to get in the practice of bottle carbonating a few bottles for my upcoming exBEERiments so I can see if there’s a noticeable difference.
Very interesting article. I have seen lots of whole vs. pellet discussions. This is the first experiment I’ve seen like this. This experiment shows why beer experts say dry hopped beers are best drank fresh and not aged.
I’ve been honing in a hugely hopped IPA recipe recently- lots of hop stand additions and around 4 oz of dry hops per 5.25 gallons. The results have been good using both leaf and pellet hops as the dry hop charge and I’m starting to think that a mixture of the two works best for me.
The thing is all three iterations of this recipe have come out punch-you-in-the-fucking-face-fresh. The characteristics of the hops are easily identifiable in both aroma and taste, but one week later the hop character of each has developed into a different beer; tasty, but a pale shadow of what they were.
It’s shocking how small the window has been, and I am bent on finding better techniques for locking in that aroma. It’s a bit dismaying to hear that you’ve experienced something similar.
I was rather shocked that it faded so fast too. I obsess over keeping oxygen out of my system, keep everything perfectly sanitized, and yet still lost the hop aroma so quickly. I have noticed my hop stand aroma sometimes seems to stick around longer than my dry hop aroma for some reason.
Same here! My Double IPA dry hopped with 2 oz cascade and 2 oz chinook was amazing when first tapped. After a week it had noticeably less hop aroma and flavor and now 2 weeks later it is a totally different beer. Luckily the keg is almost dead 🙂
Your comments make me wonder if the CO2 is causing the degradation . . . or is it just time? Would nitrogen be different? Maybe try an Xbmt to see!
I found it all very interesting. Keep up the good work!
Great writeup! Due to the fleeting nature of hop aroma I typically prefer pellets because they’re easier to handle/store.
I used to be a PG member when I lived in LA, good to see the old gang 🙂
You might want to repeat this experiment. 60 grams of pellets and whole hops have a different utilization level. I believe BeerSmith can approximate the correct amount needed for each to be the same utilization amount. I could be wrong but I believe the results would be different if the the utilization levels were the same as opposed to the weight (just thinking off the top oft head without verifying). I also think there have been experiments done on this issue. In remember reading something about this somewhere; maybe the Brewers Publication Hop book or an article? Hope my thoughts help.
Thanks for the response! I’ve only used beersmith once so I may be wrong here, but I think the utilization they would be calculating is for bitterness (IBUs) extracted during the boil. The increased surface area of the pellets increases the isomerization of the alpha acids and ups the utilization. Simply put, you can uses slightly less pellets and get the same bitterness as leaf.
Now for dry hopping, we are talking hop oil extraction, and it gets even weirder. If you really want to get uber technical on pellets vs leaf, read this: http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/34093/Wolfe_thesis.pdf?sequence=1 . In one section Wolfe discusses hop oil extraction, and he found that you will extract differing amounts of various oils from pellets vs leaf. Since we’re dealing with varying extraction rates as well as varying oils, there isn’t really a utilization rate you can use to compensate between the leaf and pellets for dry hopping.
i keep hearing that leaf hops have “additional plant matter”, and I just don’t get it. I thought pellet hops were just chopped/pounded and compressed. I mean, the whole cones are used when making pellets, nothing is removed, right? Am I missing something here, or is this just another homebrew “truth”?
That’s an interesting point, and I think you may be right. There are two types of pellet hops: type 45 and 90. The type 45 pellets do get concentrated and would have less plant matter. But the type 90 that we homebrewers generally use are like you said, just chopped and compressed with only 10% waste. I suppose if you use less pellet hops to get the same bitterness then there would be less plant matter in the boil but that wouldn’t be relevant at all to dry hopping.
Greg,
Great xBmt, in my experience hop aroma fades extremely quickly even when bottle conditioned. I made an all Citra IPA with a nearly identical grain bill and hop schedule as the one you made. The first bottle I cracked open (after about 2 weeks of bottle conditioning) filled the entire room with hop aroma. By the time I finished the batch a couple of months later I had to get my nose wet before I could detect the Citra.
It would be interesting to try something similar for the whole hopping process, not just dry hops. You’d have to compensate for the different utilization as mentioned in the above (below?) comment, I guess.
This is definitely on the list 🙂
Hi!
I agree with “marctr”. To distinguish the difference between hopping with fresh cones vs. pellets in the boil. Preferably not dry hopping since we already know the results from that.
Upon reading that you were using Centennial hops I thought to myself, “he should do a Bell’s 2 hearted.” Pleasantly surprised. Nice write up.
I am a commercial hop grower, this is what you need to remember about dry whole hops vs. pellets… 1) dry whole hops impart 70% more myrcene during the dry hop brew phase than pellets – that’s science not an opinion 2)The hop lupulin is exposed to heat three times as it is becoming a pellet, first during whole dry phase, secondly when it’s smashed/baled, and thirdly when it’s smashing through the pelletizer, therefor this changes the lupulin properties from within the same batch of whole dry hops off the same bine. 3)Your test can never be a same for same even if the hops come off the same bine for exactly ‘that heat reason’. Terroir of hop is everything. True terroir only comes from a whole dry hop – ask a grower. Your eyes can tell you the purity of the hops in your brew with whole dry hops – you will never know the amount of trash in your pellets. That same pellet is different if it is made with hops from the outer 6″ of the bales vs. being made from the hops in the center of the bale. The center of a stored hop bale degrades slower than the outside but holds more heat while it waits to be processed. Also, pellets are made later in the year post-harvest after the dry whole hops have been smashed into a tight bale where they have already been bio-degrading – the older the bale… the worse it is. Never accept any hop in any form older than 12 mos. – your lupulin will already have been seriously compromised. Science requires ‘apples-to-apples’ or ‘hops-to-hops’ comparison and because whole vs. pellets can never be truly same-to-same… your test will always be subjective – but your beer will tell you everything.
This is fantastic info, thank you!
Thank you so much for taking the time to post this info! I’m really interested in your statement that dry hopping with whole leaf imparts 70% more myrcene. The only data I’ve seen on this is in the oregon state thesis I linked to a few posts up. In that test they found higher myrcene levels were extracted across the board with pellet hops.
“dry whole hops impart 70% more myrcene during the dry hop brew phase than pellets – that’s science not an opinion”
With respect, you seem a little confused. They contain 70% more myrcene than pellets, but pellets “impart” more myrcene to the final beer as the utilisation is so much better :
http://inhoppursuit.blogspot.co.uk/2011/07/hop-oil-is-bigger-better-preview-of.html
“Even though the whole hop has about 70% more total myrcene than a typical pellet, the amount of myrcene from the flower that is dispersed into your pint glass appears to be substantially less (5.5 ml vs ~6.5 ml). A far lower amount of myrcene is “extracted” compared to a pellet (5% compared to 17%). It appears that a big chunk of the myrcene in the whole hop is lost.”
Another interesting point in that article is that the oil in pellets is 40-45% not-myrcene/humelene, whereas in leaf that number drops to 20-30% (Cascade in both cases). Potentially there’s lots of interesting flavour compounds in that non-myrcene/humulene fraction.
Of course, aside from the handling thing, the big reason for using pellets is that they store much better, so beer is more consistent through the year.
As for the processing of pellets – sure any extra processing is Not Good for delicate hop chemicals – but as anyone who has drunk wet/green hop beer can tell you, the biggest loss of volatiles happens in the initial drying, which is common to both “normal” leaf hops and pellets.
It looks like we have the same scale, mine was bought at dx.com
Hey – what’s the story with the repurposed dry-hop filters? I’ve been thinking of buying a couple. Looks like you’re employing them differently to their intended use. What’s your experience been?
thanks
rowan
If I can freshen up my coffee with short pour from the pot, then why not add a little more hops each week to keep each glass fresh?
Keep doing a closed system transfer onto new hops every week with whatever remains in the keg
Just stumbled upon this. Awesome experiment, thanks for the detailed blog post.
Cool experiment and nicely written. How do you think the drinking vessel affected your results? It looks like some of the participants were drinking from solo cups and others from tulips. Can you go back and look at pictures and see if the glassware had any affect on choosing the beer correctly?