In terms of smell, humans are often denigrated as being much poorer than bears or dogs. Compared to mice, it’s true we have only a third as many working receptor types, but we have way more copies. It’s a fair bargain, because their extra receptors involuntarily control their behavior, while our cognitive brain does these tasks with far more flexibility—and free will. Each creature has its own lifestyle, and its sensory systems are adapted perfectly to it.
Part One: Signal Processing
Unlike manufactured systems, our senses can’t rely on highly accurate and linear sensors to convert external stimuli into usable signals. Biological systems are inherently variable, noisy and limited in range, yet we need clear and accurate information to guide our behavior. How do we manage to do this?
This upcoming book took six years of mostly full time effort to write and edit.It was transformative for me, and I hope the information will be for you as well. Here are some of my major takeaways about our amazing chemical senses and the ways they are processed in the brain.
It’s obvious that we human beings are all pretty different from one another—in appearance, experience, attitude, gender, and countless other attributes. Each of us has things that come effortlessly and others at which we struggle. It goes without saying that these differences affect our abilities as tasters. But how, exactly?
Beer is more complex than any other beverage known. No one’s keeping the master list of odor chemicals, but it’s huge. Hops alone contain more than 1000 terpenoids with citrus, floral and other aromas, with many other chemicals, too. In malt, Maillard and other browning processes create hundreds more. Fermentation and subsequent maturation creates a third enormous family of aromas, yet there are more. Add them all up and you get far in excess of the widely quoted number of 600–1000 odor chemicals in wine.
From the glass on the table to the smells of the beer frothing up, to the sights and sounds of the barroom and beyond, our world usually feels solid and reliable enough. It is an illusion, however—nothing more than a projection created by our highly fallible perceptions. Ancient wisdom makes a point of it; modern science increasingly verifies this unsettling truth.