We answer the question you may or may not have asked.
Breweries put a lot of hard work into ensuring their product is delivered to consumers in a fresh and ready-to-drink state. Not all, but many go through the effort to also put a packaged-on or best-by date on their beer.
What is the significance of these dates? Are they a specific, concrete rule dictating the beer’s quality of flavor? Once the best by date, or recommended timeframe passes, is there a magical switch that flips instantly, turning the beer bad?
. . . Okay, no, not really.
No beer has an exact amount of time that it is “good” for and though general rules of thumb can be helpful, they ultimately will fall short of giving you all the information you need in order to assess the freshness of a beer.
The best way I’ve found to approach the question of beer freshness and having an idea of when a beer is still retaining its flavor is to understand what happens to certain aspects of a beer’s flavor profile as time goes on.
Let’s start with the ones who leave the party first: that would be hops. You know all those intense fruit, citrus and piney, herbal hop flavors you love? The chemicals responsible for those flavors are generally the first compounds that begin to deteriorate. There’s a reason that the common suggestion is to drink hop-focused beers, say for instance Send It pale ale, before they are 90 days old. As the beer ages and these flavors diminish, you are left with a dull bitterness that is, well, gross. Even this bitterness will eventually fade and leave you with a completely unbalanced and bland liquid.
Malt flavors take a bit longer to fall apart but the eventual result is just as disastrous. Certain particles from malt like proteins and lipids tend to clump up and fall out of solution. Among other things, this causes the beer to become thin and watery. These malt particles are also great at helping protect beer from the negative impact of oxygen. This is nice in the short-term but down the road will end up contributing to oxidized flavors in the beer (think wet cardboard). These changes can be especially apparent with beers that rely heavily on malt for their flavor and who wants a thin, cardboard-flavored Irish Death? Not me.
Yeast and bacteria a.k.a Agents of Fermentation (which would be an awesome band name, fyi) are the most enigmatic variables here. The most important differentiation to be made is whether the beer in question is bottle-conditioned (there is yeast and/or bacteria intentionally put in the packaging with the finished beer) or not. If the beer has not been bottle-conditioned then there will ideally be no impact from these forces. I say “ideally” because there are situations in which these little guys get into a packaged beer when they’re not supposed to. In these instances, the beer’s flavor can be altered drastically from something as surprising as sour to as awful as sewage. On the other hand, if a beer has been bottle-conditioned, the brewery intended for the yeast and/or other microorganisms to change the flavors over time. Even these bottle-conditioned beers can fall prey to negative effects from their yeast. As yeast die, ahem, go through autolysis (fancy beer term for when yeast die) they will give off flavors akin to soy sauce. I don’t know about you but I prefer soy sauce on my food. At Iron Horse, we don’t bottle-condition our beers so that makes this aspect of flavor relatively straightforward. Sit back and relax, you don’t have to worry about that.
Carbonation is another important (though often overlooked) aspect of most beers. Regardless of the type of packaging, all beer will experience some amount of impact from oxygen over time and this will have an effect on the level of carbonation, As this occurs, you can expect the carbonation in a beer to decrease. Carbonation plays a role in the balance of a beer’s flavor and as it decreases, the perception of other flavor components will change. Sweetness is a great example of this due to the fact that carbonation “cuts” through the sweetness, making sure it isn’t cloying. Without adequate carbonation, a beer can seem overly heavy or sweet.
I know I haven’t given a straightforward answer for when a beer is good and when it is not but the truth is, there is not one answer to this query. All beers have a unique chemical makeup and this means they will change differently and at different rates over time. I encourage you to keep in mind what beer that isn’t fresh may taste like and hopefully this helps in discerning what you would like to drink. As always, my goal isn’t to tell anyone what to drink but in some small way, I want to make your beer-drinking experiences more enjoyable.