As brewers and beer enthusiasts, we fuss over every little thing, whether it’s the best ingredients or processes, classic or inventive recipes, or ratings, reviews, and the latest hop-du-jour. But how much attention do we pay to how fresh our beer is? Do we recognize the complex, telltale signs when a beer is past its prime?
Beer is a fragile product that’s in absolutely pristine condition for only a brief window of time. Maybe you’ve heard a friend come back from Europe and say (or maybe you’ve come back from Europe and said), “It’s so different over there; it’s not even the same beer.” It’s true. Any beer, no matter how well brewed, that’s made a weeks-long trip by ocean freighter, truck, and other means, is absolutely different from the one that left the brewery, both in terms of its flavor and its chemistry. Time, temperature, and vibration all take their toll. This is an inviolable law.
Stale beer is a big issue for the industry and for discerning drinkers. Over the decades, more research money has been poured into staling than probably any other problem in brewing. It remains the most intractable one. The issue is that beer is not, as chemists say, “in equilibrium.” If it were, its chemicals would be at their lowest energy state, with no potential for further reactions—a perfectly stable product.