What the Nose Knows
The olfactory system is vastly more complex. Nine million neurons of about 1000 types are together capable of registering 10,000 different aromas. Despite a huge amount of research, the chemistry and physiology of olfaction is still poorly understood, and is a fascinating area of study.
The olfactory receptors are in two places: in the nose, as you would expect, and a second cluster at the upper part of the back of the throat, connected to the brain by different wiring. Recent studies have shown that the aromas sensed through these back-of-the-throat sensors are perceived more as flavor than aroma per se. Also, they seem to be involved in food preference, which means they may have played a part in your childhood hatred of broccoli.
An important concept is called potentiation. Sensory neurons respond only to a change in stimulation, which means they stop firing when they become saturated, giving rise to the experience we’ve all had of coming back inside the house and re-experiencing a smell we’d been completely ignoring until stepping out for a while. This is why experts recommend you do your sniffing in short bursts instead of a long heavy inhalation. And if a particular scent is baffling you, this is why it’s good to give it a rest and come back after a minute or two.
Your olfactory system is wired like no other sense. Signals go very deep into the old lizard parts of your brain: the hypothalamus, seat of appetite and fear; the hippocampus, regulator of memories; and the brainstem, responsible for regulating basic bodily functions. To a taster, memory is a valuable tool in identifying aromas. Scents often generate a vivid memory of some other time and place. Dwell on this memory, have a look around, look to see what’s making the smell. Is it the flowers in Grandma’s backyard? Cookies in the oven? A freshly toppled oak tree? Zap! You’ve got it. It’s amazing what you can find rattling around in those old aroma-triggered memories. It really is a different kind of learning.
Sight is such a huge part of our sensory input that it’s hard to ignore. We all drink with our eyes far more than we should. That said, the visual aspects of beer—like a rich foamy head—have been appreciated for millennia. Texture and color can be valuable clues to a beer’s character, or simply misleading. Don’t rely too heavily on your eyes.
Fred Eckhardt’s sage advice to “listen to your beer” may offer limited information unless you heed the deeper meaning in his message: use all your senses, and never take anything for granted. Pay attention and you will be rewarded with a rich experience, in beer, as in life.