Beer Fact Friday: How We Smell Beer
Welcome to another Beer Fact Friday, our weekly pre-weekend dive into beer-related topics. Today’s subject: The way we smell, and how it affects our beer-drinking experience.
You’ve probably seen ads coming out of big breweries that tout their beer’s “crisp taste.” Vocab issues aside, there are really only five tastes your tongue can pick up: sweet, sour, bitter, salty, and umami (often also referred to as “savory”). What many people consider a beer’s “taste” is actually its “flavor,” and flavor is actually a combination of two different senses: taste and smell.
Of the two senses, smell is probably the more powerful and important. The aspects of beer that we most enjoy, from malty notes of caramel, bread crust, or cocoa to bright hop qualities that mimic grass, pine needles, spices, or tropical fruit, are all derived from aroma. The sense of smell ties directly into the most primitive parts of our brains; a particularly strong odor can surface memories you haven’t thought about in years or even decades. More than 1,000 genes are devoted specifically to our sense of smell.
We smell beer in two ways: orthonasally and retronasally. Orthonasal olfaction is what happens when you sniff an object—a glass of beer, for instance—and pull aroma particles through your nostrils. Retronasal olfaction occurs when you actually sip that beer; aroma molecules rise off the tongue during and after the swallow, travelling upward through a connection close to your throat. In both cases, aroma particles flow through your nasal cavity and hit your olfactory bulb, which detects different odors and sends signals about each of them to your brain.
It’s important to note that orthonasal and retronasal smelling can bring about very different impressions of a beer. Moving the beer on your tongue both warms the liquid and spreads it over a wide surface area, which volatilizes some aroma molecules that might not be so easily picked up via sniffing. The best way to enjoy beer is to be both ortho and retro in your smelling: Give your beer a few sniffs before each sip, then be sure to note the aroma generated as you swallow and breathe out.