Remember that tongue diagram you learned in school? The one divided into sweet, sour, bitter and salty zones, with each occupying very distinct territory? It's categorically wrong.
This is just one idea debunked by Pulitzer Prize-winning journalist John McQuaid in his new book Tasty: The Art and Science of What We Eat, as he deconstructs the maddeningly elusive worlds of taste and flavour. (As it turns out, all tastebuds can sense all five tastes, including savoury umami, almost equally.)
When it comes to the study of sensation, taste has always been the poor cousin. It is, after all, difficult to form an objective hypothesis when the intricate web surrounding food – including appearance, smell, texture, temperature, branding and even memory – is so subjective. This is slowly changing, however, as scientists use advances in microbiology, genetics and molecular biology to delve deep into taste and its elusive cousin, flavour.
As humans, from hard-core competitive 'chili-heads' to picky eaters, are poked and prodded in the name of progress, the science of taste is only now catching up to our understanding of, say, vision or hearing. And this, according to the author, will have profound consequences for how, and what, we eat.
In this quick, engaging read, McQuaid takes us along paths both new and well-trodden, in an effort to achieve what many books have tried to, and failed. Travelling from the evolutionary science of our forebears' ancient hunger to fermentation as the uncharted frontier, Tasty provides, in this "brief biography of flavour," a delectable road map to where our tastes began and where they might be heading.
Is liking Brussels sprouts a matter of discipline or biology?
A couple of generations ago, the idea was that you should eat your broccoli or your Brussels sprouts, and if you're not eating them when you're a kid, then you should be made to eat them, whether you like them or not. Not liking them was just making trouble.
Since then, we've learned that everybody does have these very strong likes and dislikes, particularly children, who tend to be picky eaters, and there's not much you can do about that. In some kids it's a real problem. They become so picky that it affects their nutrition. In terms of discipline, there's not really much you can do. There's this very complicated dynamic between biology, what's determined by genes, and also by environment and development.
How has our sense of disgust separated us from our food supply?
When people were living in the wild, thousands of years ago or longer, they would hunt animals and slaughter them and not get squeamish about it, as far as we know. But now we live in this hierarchical culture where a lot of the unpleasant stuff is walled off, both physically and mentally, so we don't need to see or think about animals being raised in inhumane conditions and then killed, humanely or not, in order to bring us our steak, which is delicious. Disgust is a really complicated emotion that's based on these visceral taste sensations, but we've applied it to all these other things, including culture. I think it might help us if we did see it more often and were more aware of where food comes from and what's done to bring it to us.
You compare eating a super-hot chili to childbirth – enduring pain to achieve a greater reward. Where does it come from, this desire to derive pleasure from pain?
That is a real mystery: Why do people like these sensations that are objectively painful or unpleasant? You look for the answer in biology or neuroscience, but they don't offer much explanation. You end up returning to psychology: It's just a human thing, which cannot necessarily be explained by firing neurons.
People are driven to extremes: Peppers, spicy food – most people like spicy food up to the point where it becomes unpleasant, and that's their ideal level of spiciness. Some people push it beyond that to total burn. There's some fundamental dynamic at work where people want to test themselves, push their sensation in new directions.
Are we setting up a taste backlash? Are people starting to crave purer, more simple flavours?
These things work in cycles. There's this bombardment of the senses, which desensitizes people. Inevitably you'll see the pendulum swing back and people will say that we need to dial this back, to appreciate the subtler flavours that we're missing out on. Because we're getting bludgeoned by bitter coffee and super-hot peppers.
Where is all this scientific progress taking us?
There's a lot of really freaky stuff going on, most of which we won't see in supermarkets for a while. There's the idea of virtual taste, where you attach some sort of clip to your tongue, plug it into your laptop and download a nice meal. You'll get the sensation of a steak dinner with mashed potatoes, without any of the calories.
In the more near term, I think you'll see more fermented foods, which is now filtering down into the food system. At a cheesemaker I visited in Vermont, they were working with a much larger cheese manufacturer, giving them space in their cheese vault, and helping them craft the flavours of these large cheddar wheels. As that becomes more science-ized, for lack of a better word, as they learn more microbiological facts about how fermentation works and how to manipulate that, you're going to see cheeses become much more interesting. But you'll also see huge microbial factories being built. It's going to be weird.
How does our future depend on flavour?
It depends on food, obviously, and the point of the spear is how food tastes. People in 10 years will be tasting different things than we are today on a regular basis. That will change the whole quality of life and what life feels like, meal to meal.
This interview has been condensed and edited.
ON THE FLAVOUR TRAIL
While researching Tasty, John McQuaid travelled and tasted his way around the world, from Iceland to South Carolina, with his wife and two children, Matthew, 13, and Hannah, 11, in tow. These family road trips add a personal, on-the-ground atmosphere to a book that might otherwise seem slightly academic. A few of their notable experiences.
On eating fermented shark in Iceland:
We drove up to this little farmhouse and museum, where they make this hakarl, this fermented shark meat. As you walk up to this shed where the meat is curing, 50 feet away you get this huge whiff of ammonia. The meat is literally exuding ammonia and fish-rot aroma. We said, 'Do we really want to do this?'
My daughter spat it out, and my wife and son and I ate it. You chew it, and then there's a secondary wave of this ammonia fish-rot. You power through it, swallow and then you eat some bread to try and clear your palate. It really forces you to think: Why do people like this? What is flavour even about?
On eating a super-hot chili with his son:
My son said that was one of the best experiences of his life. He has always been a real chili-head. So we visited Ed Currie –he grows this super-duper hot pepper. He fed us really tiny slices of this Smokin' Ed's Carolina Reaper, a few millimetres across. It takes 10 seconds before it starts affecting you, and taps into your body's heat-regulation system. We were sitting there, freaking out a little bit, and I developed the hiccups and Matthew stood up, shaking his head in alarm. We were with a bunch of other people and they all found it pretty amusing.
On his kids being used as guinea pigs:
They're a little embarrassed.