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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