Author: Marshall Schott
When it comes to brewing beer that tastes good, it is often highly recommended to use fresh ingredients. Grain stales, yeast dies, and hops lose their oomph. On the professional level where ingredients are blown through in a matter of a few weeks due to production volume, freshness may not be nearly as big of a concern as it is for homebrewers, many of whom have begun purchasing in bulk to save some coin. Naturally, some of these ingredients are going to be around for awhile, certainly long enough to fall off of the spectrum of “fresh” in some minds. While there’s little we can do to stop the impact of time, homebrewers have employed some clever techniques for storage of ingredients to help prolong their life such as keeping unmilled grain in sealed containers, leaving harvested yeast under starter beer, and perhaps the most popular, storing vacuum sealed hops in the freezer. I can say from personal experience these methods work well, but I’ve never actually done a side-by-side comparison. Until now.
I was contacted by Brülosophy reader Mike Gutenkauf back in June 2015, he offered to send me 8 ounces of old Willamette hops for an xBmt. Cool, free hops! He then explained he purchased these hops in 2006, they were from the 2004 crop, and he kept them stored in a vacuum sealed bag in the back of his freezer where he forgot about them… for 9 years. Mike was curious how much a beer made with these old hops might differ from a beer made with fresher hops of the same varietal, as was I. And how often does the opportunity arise to play with 10 year old hops?
Prior to embarking on this xBmt, I dug around for more details on the commonly accepted claims regarding the impact age has on hops. Much of what I found focused on the impact of secondary variables such as oxidation on hops over time as opposed to age alone. For example, in his 2008 Brew Your Own article, Behind The IBU, John Palmer references a study where researchers found a beer brewed with hops stored for a year in a “punctured oxygen-barrier bag” to be notably different in many ways than the same beer brewed with fresh hops. I also found a post at the Beer Sensory Science blog where the author discusses how poorly stored old hops can produce grassy character in beer due to the presence of cis-3-hexanol, a “grassy” compound that arises from the breakdown of particular unsaturated fatty acids present in hops. Both of these articles, along with quite a few others I found, provide fascinating information about the impact improper storage over a relatively short period of time has on hops, but what about properly stored hops that are just really fucking old?
| PURPOSE |
To evaluate the differences between old hops and fresh hops that have been stored well when used in separate beers of the same recipe.
| METHODS |
I received the old hops from Mike in late June, at which point I ordered 1 lb of 2014 Willamette from Hops Direct. I expected the stats to vary, but the nearly 2% difference in alpha acid was rather surprising to me.
In an attempt to increase the chances of tasters actually noticing a difference, and also trying to avoid accusations of a shitty xBmt design, I threw together a simple Blonde Ale recipe with a small addition of Magnum up front, as I only had 8 ounces of the old hops and didn’t want to blow a huge load on bittering.
Willamette Blonde Ale
| Batch Size | Boil Time | IBU | SRM | OG | FG | ABV |
| 5.25 gal | 60 min | ~20 | 4.5 | 1.043 SG | 1.008 SG | 4.6% |
Fermentables
| Name | Amount | % |
| Domestic 2-Row | 13 lbs | 95 |
| Gambrinus Honey Malt | 8 oz | 5 |
Hops
| Name | Amt/IBU | Time | Use | Form | Alpha % |
| Magnum | ~18 IBU | FWH | Boil | Pellet | 11.2 |
| Willamette | 14 g | 10 min | Boil | Pellet | 2 |
| Willamette | 50 g | 0 min | Flameout | Pellet | 0 |
Yeast
| Name | Lab | Attenuation | Ferm Temp |
| WLP029 German Ale/Kölsch Yeast | White Labs | 77% | 66°F |
I created a yeast starter 2 days prior to brewing, some of which was stolen for later use while the rest would be split between the 2 batches.
The following evening, I prepared as I usually do by collecting the brewing liquor, adjusting water chemistry, then measuring out and milling the grain.
I woke up early the next morning and got to brewing, staggering the start of each mash by about 30 minutes. Thanks to BeerSmith, my mash temps were consistent between both no sparge batches.
Once each mash had completed their 45 minute single infusion rest, I collected the wort in my 14.5 gallon kettles and proceeded to boil.
After an hour of boiling, each wort was quickly chilled to 6°F above groundwater temp, which at 88°F was a bit warmer than my target fermentation temp.
A refractometer reading confirmed my process was consistent between both batches with each sitting at 1.044 OG, slightly lower than my target because I completely forgot to adjust for an annoying sack of grain.
I transferred the wort into separate 6 gallon PET carboys and placed them in a cool chamber to continue cooling. A few hours later, both had dropped to my target fermentation temp, so I evenly split and pitched the yeast. Active fermentation was observed about 8 hours later and proceeded similarly for both batches.
After 3 days, I bumped the temp to 72°F where I left it for an additional 3 days to encourage complete attenuation and cleaning up of any fermentation byproducts. I pulled hydrometer samples on days 6 and 8 to confirm a stable FG, both beers had reached 1.008, so I cold crashed for a day, fined with gelatin, then packaged, hitting each keg with 40 psi of CO2 for 24 hours before dropping it to a serving pressure of 13 psi. The beers were perfectly carbonated and nearly bright just 10 days after being brewed.
I waited another 3 days for the weekend to arrive before presenting the beers to participants for evaluation.
| RESULTS |
Overall, 21 people lent their taste-buds to this xBmt including multiple BJCP judges, homebrewers, and craft beer drinkers. Each participant was served 2 samples of the old hop beer and 1 sample of the fresh hop beer then asked to identify the sample that was different. Given the sample size, 11 tasters (p<0.05) would have had to correctly select the fresh hop sample as being different in order to reach statistical significance. Only 5 tasters (p=0.82) accurately identified the odd-beer-out, a response rate more consistent with random chance than actual ability to distinguish between the beers.
The results of the comparative evaluation completed by the 5 tasters who were correct on the triangle test yielded no meaningful data since significance was not reached, but to satiate the curious, I’ll share a few bits and trust it’s interpreted appropriately. All 5 tasters agreed the aroma of the old and fresh hop beers were somewhat similar with 1 person noting the fresh hop sample as being “slightly fruitier and not as clean and crisp” as the old hop sample; preference for aroma was split. Similarly, 4 tasters reported the flavor as being somewhat similar while 1 thought it was exactly the same; of the 4 who noted some difference, 3 preferred the old hop beer. Regarding mouthfeel, 2 tasters experienced the samples as sharing no similarities while the other 3 thought they were somewhat similar; 4 preferred the mouthfeel of the old hop sample while only 1 preferred the fresh hop beer. Overall preference goes to the old hop beer, which was preferred by 4 of the 5 participants completing the comparative evaluation. Once the nature of the xBmt was revealed, 4 tasters inaccurately believed the old hop beer was the one made with fresher hops.
My Impressions: My immediate thought when I first sampled these beers next to each other was that they were far more similar than I expected given they came from crops 10 years apart. It’s often discussed how hops of the same variety change from one season to the next, but this didn’t seem to be the case with these beers. Perhaps Willamette is more stable than other hops, I don’t know, but to me this was promising. As far as differences go, I was not able to reliably detect enough differences to tell these beers apart, failing 3 out of 5 of the quasi-blind triangle tests I had others help me with. This is sort of interesting, as in my own side-by-side comparisons, I could have sworn the fresh hop beer tasted, well, fresher? Despite looking for some of the differences mentioned by those participants who were correct in the triangle test, I had a hard time finding them, which I’m comfortable accepting may be more the product of my inept tasting abilities than anything else. Either way, my concerns about using old hops that have been properly stored have definitely been reduced.
| DISCUSSION |
This is one of those xBmts I assumed would easily produce a significant result, as I’d been under the impression the aromatic and bittering qualities of hops degraded as a function of age alone. Of course, the old hops used in this xBmt were stored in arguably ideal conditions– vacuum sealed and in the freezer. Perhaps more than anything, the results of this xBmt seem to confirm the negative effects age has on hops can potentially be ameliorated by utilizing adequate storage methods, which requires only 2 readily available and inexpensive things, a vacuum sealer and a freezer.
I’m not sure these results are necessarily generalizable to all hop varieties, at least at this point, as there is a chance different hops with their different properties react differently to time, even when stored properly. Either way, my anecdotal experience absolutely supports the idea that well stored hops, from Tettnanger to Mosaic and so many in between, do indeed continue to impart all of the character I expect even after 10+ months in the freezer.
I’m now more curious than ever about the the impact poorly stored hops have on beer and plan to design an xBmt to test that soon. Until then, please feel free to share your experiences in the comments section below. Cheers!
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41 thoughts on “exBEERiment | Impact Using Old Willamette Hops Has On A Blonde Ale”
I’ve always gone with the policy that if the hops aren’t brown or yellow (i.e, they’re the same color as fresh hops) then they’re good to use. I don’t even vacuum-seal my hops when I put them in the freezer, I just put them in a zip-loc bag and squeeze out excess air.
Pretty much the same here. I keep them in their original foil packaging and roll them up then put a rubber band around them. I think as long as they remain frozen they can last a long time.
Probably depends a bit on the freezer. If it’s a deep freeze you are probably OK, a regular “frost free” freezer regularly gets warm enough to keep frost from building up and that cycling will “freezer burn” things that are not vacuum sealed.
I’m about to brew with some magnum and crystal hops I found at the local hardware store sitting in puffed up sealed foil packs on the shelf for who knows how long…I’ll let you know how those taste..
Assuming the were nitrogen flushed, I’d bet they’ll be okay.
Did you notice any difference in the aroma or the coloration of the pellets themselves?
Aroma- not at all, it was very surprising; coloration- yes, I took a pic to try to show it.
Thanks for an interesting experiment — I am right at the point of deciding whether to clean out my stores of hops in the freezer. When I lived in San Diego County, the hops at the homebrew shops were pre-packaged, which meant I had leftovers. Now that I live in Los Angeles, I can measure out exactly what I need per batch and not one ounce more — love it. This is especially helpful when you are planning a one-gallon batch.
Great job on this one Marshall. Ive been concerned about the properly stored hops as well, and this has calmed me down a little bit. Cheers!
Thanks Ed! I was so convinced there’d be a difference… nope.
I suspect that milling grain and keeping it sealed in the bag with a twist tie for 6 months will prove to be as good as fresh too. We’ll see…..
I’m intrigued by the similarities from a bittering standpoint, too…I’ve always worried a little about loss of alpha acids over time; Willamette has a hop storage index of 40%, so it is very interesting the batches were so similar (even with the old hops frozen and air-tight)!
I’d be interested in the effect of time on bittering potential. Looks like you went just for impact on flavor/aroma here, which is great (and thanks, because I’ve got a ton of 2-3 year old hop pellets in my freezer I’ve been avoiding, thinking they were too old, but can’t bear to just throw them away), but I always hear that it’s alpha acids that degrade with time. Hard to re-do this one though, unless you find more old hops to use!
If you’re interested in running this again I have some 10yo Cascade, Amarillo, Simcoe, & Tettnang. All have been vacuum sealed & frozen for the duration. I still use all of them regularly with no ill effects.
Dude. That’s rad. Shoot me an email: marshall@beerconnoisseur.local
Email sent.
Great idea. Can someone provide a sample that is vacuum sealed in mylar that has been at room temp?
My LHBS keeps theirs un-refridgerated . . . so I do not buy from them.
I recently brewed two beers using my 11 month old homegrown hops. These hops were vacuum sealed and frozen. Both beers (a pale ale and an IPA) were a disaster for flavor — cheesy and grassy and just plain bad-tasting. Just to be sure it was the hops, I re-brewed the pale ale with “fresh” hops from my LHBS and it was bright, hoppy and fresh tasting.
The difference may be that my preservative method doesn’t include nitrogen flushing like the pros use.
From my experience, I’ll always trust my rub-n-sniff test before tossing hops into the beer.
Were they dried?
Yes, they were. I use the method of spreading them out on window screens in dark bedrooms with a fan running for 2 days.
I’m using vacuum sealed frozen hops from 2012 – when I discovered that buying pounds saved dollars. Willamette, Cascade, Northern Brewer, Centennial Type, Fuggle, Summit – and have not noticed any detrimental effects.
The difference here would be that your hops were bought, not home packaged. I too have used commercial hops older than a year without any detrimental effect.
this would be interesting to see ran again using whole cone hops. Supposedly pellets store much better than whole cone hops…sounds like we need another exBEERiment!
I bought the pliney the elder kit from northern brewer in August 2014. It was to be my first all grain kit. Things didn’t work out how i expected and it took until August 2015 before I brewed the beer. The grains werd unmilled and the hops were in their foil pack but not vacuum sealed.
The beer still turned out amazing. Huge aromatics and nice bitterness. All I could think was “damn, if these are year old hops I wonder how much better fresh hops would be”
Oh ok…twist my arm…i guess I’ll order another kit.
Thanks for the exbeeriment Marshall
Thanks for doing this, Marshall! I’m glad to see another momily in the process of being debunked. I was hoping you’d bitter with the willamettes, too. However, it makes sense to do old bittering vs. new bittering hops in a different experiment, just too many variables doing all hop additions with new vs. old hops.
By the way: the hops were in a vacuum sealed mason jar (foodsaver jar sealer attachment) until I needed to mail them to you. I then re-sealed them in the package shown in the experiment. I was surprised by the aroma when I cracked open the time capsule…er, jar, that is.
Thanks! and keep up the good work!
Thanks for sending the hops, Mike! I fully intended to bitter with the Willamette as well, but it would have require so much there wouldn’t have been anything left for aroma. I do think using Magnum for both helped control for that component to better isolate the flavor/aroma contributions, which was remarkably similar.
A few days ago I’ve opened two bags of Centennial from the 2013 harvest stored in a fridge. (non-freeze temp) They were packaged but without vacuum or CO2. They had that well-known raisiny/caramelly old IPA smell to them. I still used them as bittering hops, i hope i did not ruined the batch.
This is the most surprising of any exbeeriments. Also lends a lot of credibility and feasibility to buying in bulk….can you write another article to convince wives?
That is a FANTASTIC idea! Maybe I’ll interview my wife for it, haha!
I enjoyed the article. Questions though…. Did you adjust for the alpha acid percent when using each? I missed the amount of hops for both batches which seemed like it had to be different. Am I missing something? Also, did the grower adjust the percentage of alpha hops on the old batch before sending it to the guy that provided them? They were two years old at time of sale, right?
Keep up the good work. Some of your work is guiding my practice and I follow your site closely.
I did no adjusting, wanted to limit variables as much as possible. Used exact same hop amounts. Regardless, beers taste the same. It’s crazy.
I’ve been buying in bulk for a while now. I actually get mine from Yakima Valley, it’s cheaper for me to order 3.5 pounds at a time, and have them shipped all the way here to Australia, than it is to buy hops locally. Go figure.
Anyway, when I get them I put them in new vacuum bags and immediately in the freezer, and they last quite a while and have not noticed any problems with my beers at all. The hops always look fresh and green too which gives me confidence that they are fine to use. My experience so far backs this up, so I guess Yakima Valley will be getting my custom for a while yet!
Cheers
Really great experiment! Timely, too: Just bottled a small batch of an APA using 2yr old Cascade in my freezer (not vacuum sealed). Did only a gallon in case it stunk. Was pretty happy with it at bottling. We’ll see.
Created an account and subscribed just to thank you for confirming what I’ve always believed to be true from my experience. I’ve had many people doubt me and my belief that hops when stored properly can last for years.
I have some frozen, but not vacuum sealed (just tied off in bags) leaf hops that have been in my frost free freezer for 5-6 years now (i bought two whole bales thinking i’d get through them before they died on my 100L system.. mistake!) and while i’m about to trash the low aa Hersbruckers that are just too low aa to even bother with, my Northern Brewer hops are still making good beer without any skunking or stale flavours. both hops still look almost as green as the day i got em, and still smell great in the bag, I use the Hops Age Calculator of Beersmith each time i brew to make sure my bitterness is up to scratch. with the exception of one beer (a wit, so thankfully didn’t matter much) i’ve never made an under bittered beer using these old hops. I have had aroma troubles though, and i’ve recently changed my brewday to include a generous flameout and steep hopping at 80c which seems to have made a difference. but even with that i’ve had troubles with newly bought hops too,
I’ve had a few hops from homebrew shops who don’t refrigerate their hop stock and despite being the recent season, have come out of the packet looking yellow and not smelling as good as i think they should. They’ve also given me mixed results in the aroma department. bittering was ok though.
I would love to see you experiment with vacuum packed leaf hops that have been stored at different temps, eg room temperature vs frozen. and vacuum vs open (or just tied off) when frozen.
Keep up the great work. I love your sciency comparison stuff! Cheers!
Stew
Hi Stew, we definitely have plans to do more hop xBmts, I’m super interested in whole cone hops fare as well as pellets!
Would be happy to send you some of my old hersbrucker and northern brewer cones that have been frozen but not vacuum sealed for years.. but I don’t have a vacuum sealer (yet) to package em up for you to make them suitable for a journey across the pond. I should have a deep dig around my freezer. i bet i’ve got some vacuum sealed leaf hops i’ve not touched yet from the noughties buried in there somewhere haha
Oh man, go ahead and keep them, I so appreciate the offer!
That was a very suprising result.
Now is an ideal time to repeat this experiment with 2015 vs 2014 hops to see whether really fresh hops vs year old hops make a noticeable difference!
From a guy who just scored over 2lbs of various hops from the 2013 crop off CL this is pretty much the best news I could have gotten. Looks like they were all stored well so it’s time to get my ass brewing.
Interesting experiment. Thanks for doing this one. I happen to have some 2006 Willamette in my freezer as I write this. I’ll have to give them a go!
What about the effect on heavily dry-hopped beers?