The last couple of months have been a challenging time period for figuring out what beer is most suitable for a particular occasion. Part of that has been the result of some weird weather swings here in southern New England. One three-day span in February saw us go from a low of 9 below on Sunday morning to a high of 53 by Tuesday afternoon, and a bunch of days in the 60s and even low 70s in March were succeeded by some significant snowfall on April 3 and 4. (If you look closely you can see the yellow forsythia blossoms peaking out from under the snow in this photograph from my back yard.)
As a result, I found myself trying to keep a variety of beers in stock, ranging from the smoky Velvet Merlin oatmeal stout from Firestone Walker to the flavor-packed King of the Yahd imperial IPA from local brewer Foolproof to the citrusy Tropical IPA from Sierra Nevada, with a lot of variety in between.
The Tropical IPA first came across my radar at our local Irish pub, and the hints of pineapple that I got along with the usual grapefruit notes from the hops were intriguing enough that I picked up a six-pack to enjoy at home.
The Velvet Merlin was on sale at the shop trying hard to build a reputation as the purveyor of choice for craft brews. The sale was probably in large part because we seemed to be approaching the end of what I think of as “beer as food season,” a situation that connects to my other theme for this post, which is “Why and how does beer go bad?”
This was a potentially important question that came up when I tried to follow up on my Pittsburgh exposure to a beer from Tröegs Independent Brewing of Hershey, PA. Tröegs apparently doesn’t have a distribution arrangement in Rhode Island, but I venture across the state line to nearby Massachusetts frequently enough that it wasn’t too much trouble to track down a mix pack. What I failed to notice, however, was that even though I was shopping in midwinter, this mix pack was actually the autumn seasonal sampler and thus was well on its way to the “best before” data stamped on the carton, leading me to be concerned about whether I would actually be trying a representative sample of the quality of their product.
A little bit of internet research turned up what it usually does: a mix of accurate information and plausible-sounding or conflicting misinformation on the ways in which beer might or might not age well, so here are the conclusions I’ve come to after scanning through the first half-dozen or so Google hits on “Why does beer spoil?”
There is pretty near universal agreement that exposure to UV and even short-wavelength visible light is the prime culprit that causes a beer to turn “skunky” by initiating a photochemical reaction in some of the sulfur-containing compounds (thiols) that are released by the hops. The easy way to prevent this is by using dark-colored or opaque packaging: cans are obviously great here, with brown glass a not-too-distant competitor, while green glass is less good (it still absorbs most of the UV and a significant fraction of the blue/violet visible light) and clear glass (which lets in essentially all the visible spectrum) is the worst. I saw some claims that leaving your Corona out in the sun for even a few minutes was detrimental to the flavor, though no data to back up that assertion.
There was some disputation about whether repeatedly cycling the temperature up and down could contribute to a shorter shelf-life, but I was more persuaded by the writers that considered this a myth and noted that there is no clear mechanism as long as the temperature swings weren’t particularly extreme.
There was greater agreement that beer rarely goes bad due to any kind of biochemical activity, since the alcohol usually does a pretty good job of discouraging micro-organisms. It’s worth remembering that we call alcoholic beverages intoxicating because alcohol is, in fact, toxic in high doses. (We had some vivid reminders of that unpleasant fact at my place of employment this week as several teenagers—thankfully none related to me–made the poor decision to explore the boundaries of that toxicity over the weekend and subsequently discovered way too many of the drawbacks of crossing that boundary. It was a challenging week at work.)
A final contributor to long-term degradation of a beer’s flavor is the slow but inexorable encroachment of oxygen into the bottle or can where it can react with pretty much the whole spectrum of flavor components. I suspect that the unpredictability of the rate of this process is the reason that brewers tend to be conservative in suggesting a “best before” date that is typically around six months after bottling, while reputable food experts indicate you can usually safely double that time frame.
For what it’s worth, all of the beers in the Tröegs mix pack were fine, despite coming closer to the expiration date than I might have chosen. The beers in this pack included a seasonal (the Hop Knife deep amber harvest ale), two of their year-round beers (a double bock and another amber ale), plus a pale ale that no longer appears on their web site (unless they have changed the name and packaging since I bought mine). I was probably most impressed by the double bock, though that might also be linked to the weird seasonal patterns and my desire for what they refer to as “liquid bread.”
Two more installments in this crazy mix of seasons. Another sale purchase (at a different shop) was the Snow Hole double red ale from Stony Creek Brewery (outside New Haven, CT). They seem to be a pretty small operation, but based on this initial exposure they would be worth keeping track of. (I’m especially intrigued by the autumn seasonal listed on their web site as an apple cinnamon oatmeal amber ale, but I doubt the seasons are so scrambled that I will be able to find this for another several months.) And beer buddy Philip and I shared a big bottle of Gnomegang, a Belgian-style blonde ale from Ommegang Brewery with a mix of yeast and fruit in the flavor profile which impressed me enough that I bought a bottle to keep at home for some future special occasion.
With any luck, the weather will be settling into a more typical seasonal pattern—warm enough that I can put away the wool sweaters but cool enough to keep the teenagers out of trouble until school is out for the summer. One mix pack of IPAs and another of lagers are currently in the cellar, and us usual I will be keeping my eyes out for other beers of interest. Cheers!