Beer offers a dazzling abundance of sensory delights bestowed by its chemical components: water, a small amount of ethanol, and traces of sweet, bitter, acidic, and aromatic chemicals.
We can measure and express many of these in commonly understood numbers: OG, ABV, IBUs, SRM or EBC for color, and more. These basic parameters are well worth knowing, even for a casual enthusiast, because they give clues to how any given beer will taste and whether it will meet expectations for its style. Going further, it’s also possible to measure and describe the hundreds of molecular players that give beer its taste, mouthfeel, and aroma.
Useful as these metrics can be for brewers, no analysis can capture how beer actually tastes and feels to each of us. When it’s time to taste and drink, beer speaks to us purely in the sensory realm, with qualities far beyond the sum of its components.
Evaluating beers strictly by the numbers misses that important point, which is why beer competitions don’t just run the entrants through a lab and hand out awards based on how closely their numbers match the style guidelines. As an art form, beer is a multisensory conversation between the brewer and the drinker.
Beyond basic tastes, there are a few sensory characteristics that we can define chemically—whether an amber beer is toasty or caramelly, for example—but they’re quite complicated and don’t lend themselves to a reductionist approach or easy conversations. Aroma is so complex that even with some training and experience, we struggle to describe its character in dispassionate terms. We do the best we can, but sometimes even talking about a beer’s flavor can be an art form unto itself.
The closer we come to aesthetic characteristics we really care about, the more challenging this becomes. Many qualities we value highly in beer are difficult or even impossible to define.
Beer is not alone here. Despite a lot of puffed-up talk, wine wrestles mightily with this, and I assume it’s the same for all artisanal beverages. There is consensus behind many of these intangibles, so we all assume we know what we’re talking about—even when, in reality, we don’t.
When you actually try to precisely define things such as balance and complexity—or even basic concepts, such as quality—the more slippery they become.
What Can We Define?
Scientists have spent a fair amount of time on intangibles but, because they’re psychological phenomena, research hasn’t been that fruitful. Even so, there are some things we can say about a few of them.
Let’s start with an easy one: balance. Our general notion is that it’s a kind of counterpoint, preventing a beer from being too one-sided, whether cloyingly sweet or searingly bitter. This contretemps between hop bitterness and malt sweetness is the most common axis of beer’s balance, but there are others. It’s mainly about tastes and mouthfeel textures; aroma isn’t a big player in balance, but it does contribute.
One aspect of balance can be defined numerically, to a point. Looking at the ratio of a beer’s original gravity to its bitterness in IBUs gives a number that Cicerone founder Ray Daniels calls the GU:BU ratio. What it assumes is that to maintain a certain balance point, a beer’s bitterness must increase with the OG. It’s demonstrable: An American light lager of 45 IBUs will lean much more bitter in its balance than a barleywine with the same IBUs.
What the BU:GU ratio ignores is that not all beers with the same OG are equally sweet or dry. Some dark malts add astringency and/or bitterness that IBUs don’t capture. That can set up a kind of three-way balance, bouncing among sweet-malty, toasty-roasty, and hoppy. Creamy mouthfeel and aromatic fruitiness also can add to the sweetish side, as with wheat beers.
With sour beers, all bets are off—they’re more like wine. Red wine’s balance generally plays astringency/tannins from grape skins or wood against its acidity. In white wines, sweetness is sometimes at play along with its aromatic avatar, fruitiness. So, balance falls into the realm of “I know it when I taste it.” Experienced tasters learn to assess it despite the lack of any precise metric.
Complexity is more elusive, with little agreement about what the term even means. One might expect the number of smellable/tasteable components to be a good starting point, but that’s no help. Both the simplest and boldest beers have close to a thousand aroma chemicals—though, in most cases, just a few dozen of those are enough to create a believable mock-up.
That’s still overwhelming, given that even trained tasters struggle to focus attention on more than three flavor sensations at the same time. The other thing at work is how the brain uses this complex chemistry—solely to recognize aromas and assign value in a given context. Our sensory system tosses out receptor responses to the chemistry before a smell actually enters the brain.
A more fruitful way to think about complexity is to consider it from a psychological point of view, more in line with what our brains are actually doing. We now know that most aroma chemicals in things such as wine or beer join forces with others of their kind, producing “configural” smells that may be unlike any single component. Further, the sensation we experience as “flavor” combines smell, taste, mouthfeel, and cognitive information into a similarly unified whole. Could these agglomerated chunks of sensations play out as little tableaux in ways that capture our attention and imagination?
That’s the best explanation we have: Complexity happens in the brain, not in the nose or mouth. This is borne out by the fact that the most highly experienced professionals in beer or wine are the ones who can extract the most complexity out of them. For beer people, that means ingredients, recipes, and styles; for wine folks, it’s grape varietal, region, and terroir.
In other words, complexity is cognitive, depending strongly on one’s ability to perceive it. This is why it’s rarely on most consumers’ radar.
Now, quality. If it were just about freedom from flaws, this would be an easy one.
Beer is an extraordinarily fragile product that’s also complicated to produce. There are endless ways to screw it up; the minute it’s packaged, it starts to deteriorate. The telltale signs of less-than-perfect beer are taught in brewing schools and in the Cicerone curricula. But are all flaw-free beers of equal quality?
Trying to define positive characteristics that contribute to beer quality is challenging. Here are some things I look for:
Freshness is often defined as lack of staling compounds such as papery (E)-2-nonenal and honey-ish ethyl esters, while many of beer’s malt- and especially hop-driven characteristics are best when very young, fading rapidly with age.
Beer foam is a delight. That persistent head and “Brussels lace” on the glass depend on everything from ingredients to mashing, boiling, and fermentation to the carbonation process, and even how it’s served. Foam’s unique proteins also start to degrade as soon as the beer is packaged. To me, foam is the canary in beer’s coal mine. If it’s right, there’s a good chance everything else will be, too.
Getting More Ethereal
What constitutes quality has been a more central question for wine than for beer.
Flawed wines are less common than flawed beers, mostly because wine endures the ravages of time much more gracefully. Some wines are so valuable that they’re hoarded like rare coins. Are they really of higher quality? The wine world seems a little embarrassed to not be able to answer that question definitively. Sure, you can talk about prestigious estates but, in the end, whatever gets poured into the glass has to stand on its own.
Persistence or length are oft-discussed terms in wines, especially reds. That generally refers to the long tail of sensations after the sip, including the retronasal smell that hits your nose when breathing outward, plus the textural effects from tannins and other polyphenols. It can be desirable in beer, as long as it’s not harsh and unpleasant—true for wine as well. In beer, the quality of bitterness also plays a major role—is it smooth, soft, firm, crisp, resinous, or rough?
Beyond this, we go from the realm of the sublime to the ridiculous fever dreams of marketers. One wine textbook defines elegance with a straight face as “a combination of balance and quality,” two quasi-definable terms. Such generalities are endless: stylish, opulent, rich, harmonious, and others that are no more than fancy euphemisms for expensive.
I have my own ineffable term, though: memorable. This comes from years of judging, traveling, and tasting. At the end of a session, there are always beers that haunt my memory—sometimes for years.
I can’t define it and won’t attempt to, but for me that captures the mix of a great concept with some originality, all executed flawlessly. That’s what moves me. But I encourage everyone to find their own intangible stairway to beer heaven.
