Storing Hops: Vacuum-Sealed vs. Non-Purged
Conventional wisdom says that oxygen degrades hops and many professional brewers take that to extremes, such as dry hopping with only freshly opened bags. But can tasters identify a beer brewed with vacuum-sealed bags from one brewed with hops in a more oxygen-rich environment?
Process: Tester Jake Huolihan purchased a fresh package of Motueka hops, then split them half and half between a non-purged standard plastic sandwich baggie and a vacuum-sealed plastic envelope. The hops then spent 6 months in a residential freezer before they were used to brew two separate single-hop pale ales fermented with Imperial Yeast A07 Flagship. Fermentation proceeded for 3 days before dry hopping, and within 8 days, both beers had reached the same final gravity. The beers were crashed, fined, and kegged where they were burst carbonated.
Result: Tasters were served three samples, one made with purged hops and two with unpurged, but of the 16 tasters only four could pick out the odd beer, a statistically irrelevant result. However, the tester was able to reliably identify the purged sample 5 out of 6 times, perceiving some of the latent flavor from the freezer in the hops.
Verdict: Mixed. Requires more testing to isolate individual factors such as temperature that may have impacted the test.
Enzymes: Add to Mash or Fermentor?
Anyone trying their hand at a brut IPA has to face the question of whether to add amyloglucosidase enzyme to the mash (hot side) or to the fermentor (cold side), but does when you add the enzyme produce a tangible flavor impact?
Process: Tester Malcolm Frazer designed and brewed a dry and hops-forward brut IPA using Pilsner base malt and Southern hemisphere hops (Galaxy and Nelson Sauvin) that he the fermented with WLP090 San Diego Super Yeast. One version of this brew received Amylo 300 (amyloglucosidase enzyme) at dough-in while the other received a similar dose on the cold side when the yeast was pitched. Both beers were fined, crashed, kegged, and carbonated.
Result: Two immediate results were visible—the hot-side version was slightly hazier than the cold-side version, and the cold-side version attenuated further than the hot-side version (1.002 SG vs. 1.007 SG). Eighteen of 24 tasters were able to reliably distinguish the two samples, and the tester noted a distinctly maltier note to the hot-side version while the cold-side version was less sweet and lacked the bread-crust character of the hot-side version.
Verdict: Tasting impacts aside, the .005 SG difference in final gravity is enough to suggest that cold-side addition of amyloglucosidase is the superior method for brut IPA.
Dry Hopping Time: Is More Really Better?
Pro brewers use a variety of contact times for their dry-hopped beers, from short 2–3 day times up to 2 weeks of dry hops in the tanks. But does extended time for dry hopping really produce beer that’s noticeably different or better?
Process: Inspired by the difference in dry-hopping strategies between Matt Brynildson of Firestone Walker and Vinnie Cilurzo of Russian River, Marshall Schott set out to test the impact of dry-hopping time on a simple IPA. The base recipe was primarily domestic 2-row with some Munich and Gambrinus Honey Malt, and hops were designed to produce a finished beer with 55 IBUs but with almost half of the overall hops additions coming in the dry hop for significant aromatic impact. One beer was dry hopped for only 2 days, while the other was dry hopped for 11 days.
Result: Twelve of 19 tasters reliably distinguished the two beers from each other. Of those, 5 preferred the short dry-hopped one, 3 expressed no preference, and 4 preferred the long dry-hopped beer. Schott noted that he perceived a danker, more pungent and resinous character to the short version.
Verdict: Length of dry hops contact appears to have a significant impact on the overall impression, and depending on the flavor goals of the brewer, either long or short methods can be appropriate.
Wood Aging With Cubes: The Impact of Time
Using oak cubes to add wood character to a beer is simpler and more straightforward (and cost-effective) for homebrewers than racking beer into a barrel, but do short contact times lead to a rougher flavor, or do long contact times extract too much wood tannin?
Process: Tester Matt Del Fiacco set out to test the impact of contact time for a porter aged on medium-toast oak cubes. The beer was 6.6 percent ABV and brewed with Muntons Pale Malt for a base, with smaller additions of medium crystal, black patent, and pale chocolate malt. The batch was then split in two, with boiled (sanitized) oak cubes placed in one keg for 8 weeks and in the other for only 2 weeks. Before serving, the beers were racked out of those kegs and into serving kegs. They both were allowed to rest for a few weeks before serving.
Result: Of the 36 tasters, only 13 were able to reliably distinguish the two beers, below the threshold of statistical relevance.Del Fiacco was able to identify the odd beer three out of four times and noted that the beer with 2-month contact time had a slightly richer mouthfeel and a bit more intense wood and chocolate character.
Verdict: Mixed. The results suggest a test period of more than 2 months may be useful and that factors such as longer cold conditioning may mitigate other flavor impacts.