In Flavor: The Science of Our Most Neglected Sense (Norton, Apr.), science writer Holmes surveys the interplay of taste, smell, and feel.
Why is flavor such a surprisingly ripe field of scientific exploration?
I’ve always been fascinated by the sense of smell and the way it influences our behavior in unexpected ways. Also, I love to cook and eat. There is fascinating science work happening in flavor that is relatively new. We are still working stuff out, such as how many basic tastes there are, or how we detect the smell or taste of a molecule.
Can you describe some of the suggested “new” tastes beyond sweet, salty, umami, bitter, and sour?
There is some indication that people have a taste for calcium, but there is no conclusive evidence at this time. There may be a basic taste for water. Rodents have a taste for starch, but it isn’t clear that humans do. It has also been suggested that there is a taste for carbon dioxide, perhaps having to do with detecting fermented foods that might be going bad.
What was your favorite experiment that you participated in or learned about?
My favorite was trying Szechuan pepper, a seedpod in the citrus family. When you mush it in your mouth for a bit, you feel a buzz, like the lowest G on a piano. I have never felt that before and it is the most bizarre feeling. Also it was fascinating talking to professional flavorists and learning how individual elements come together to make one flavor—that wintergreen, anise, and vanilla make root beer, or that four unrelated flavors make strawberry.
Who is the coolest person that you met?
The Monell Chemical Senses Center in Philly is where some of my favorite people work. I was also impressed by Harry Klee, the tomato guy in Florida who figured out why grocery store tomatoes taste lousy and how to fix them. That is probably the most practical discovery that will impact people’s lives in the next 10 years.
What was the most surprising thing you learned?
That the human nose is quite good—better than that of rats and as good that of as dogs—but our noses aren’t down where the smells are. Human noses are optimized for flavor by the way our heads are shaped; we get the most of aromas that are inside our mouths in a way that no other organism does. We are better at appreciating flavor than all other animals.
What did you learn that you’ve used the most?
Paying attention. Everyone thinks “my nose isn’t special, I couldn’t pick out the coconut aroma in my peach or the fig note in my chocolate” but anybody who can pick out the difference between a raspberry and a strawberry has the basic perceptual tools. I now carry a wine flavor wheel because it is easier to pick things off a list than to come up with something from scratch. I also grill my steaks at a lower temperature since the research suggests that you get more of the roasty, nutty flavors if it has more time on the grill.