This issue features a “micro-interview” with Harold McGee, conducted by Rachel Khong. Harold McGee is the author of On Food and Cooking: The Science and Lore of the Kitchen, a canonical yet extremely readable 680-page compendium of food history, scientific fact, and kitchen lore. The book was hailed as a “minor masterpiece” upon its first release, in 1984; in 2004, its revised edition was met with comparably hearty fanfare. Flipping to a page at random, you might find information about breadfruit, “Guidelines for Succulent Braises and Stews,” or a poem about dumplings, circa 300 AD. McGee also writes the “Curious Cook” column in the New York Times, proffering food for the thoughtful on a more or less monthly basis: why fish-frying is greatly improved with a shot of vodka; how rats are able to distinguish between organic and inorganic produce. Prior to becoming a food-science writer, McGee studied literature at Caltech and Yale. His vocational trajectory took a turn toward the culinary when a friend asked an unlikely life-changing question: why do beans make us gassy?

–Rachel Khong

PART I

THE BELIEVER: What is it about toasting that makes toast so delicious?

HAROLD McGEE: Actually, lots of things fall under that rubric, because it’s browning with heat, and browning is basically heating proteins and sugars high enough that they begin to react with each other. Protein has no flavor of its own—sugar’s just sweet on its own—but when you heat them together they generate hundreds and hundreds of compounds that are sweet, sour, salty, bitter, and have aroma. It’s like stellar nucleosynthesis: it’s creating the universe in a star. When you toast something, the visual sign that it’s happening is the color change, and the chemical-senses sign is the developing aroma. If fat is involved you end up with fried aromas; if high, dry temperatures are involved, that’s roast flavors; if it’s very intense, very rapid heating and very close distance then that’s toasting. That’s also relatively dry. So there are distinctions among those different things, but they all come down to browning at high heat.

PART II

THE BELIEVER: Increasingly, people are becoming more conscious of the food they eat: what they buy, whether it’s grown organically or conventionally; they’re paying more attention to seasonality. Do you feel an obligation to address that?

HAROLD McGEE: It’s truer than ever that in order to sort through the really important but really basic issues around food and agriculture these days it really does help to have some perspective on what actually happens, and what you can really learn from experiments about those things. The ten-second version would be that we’re only just beginning to understand nutrition. We’re getting a little closer to understanding, but we’re always surprised by the next thing we find. In a way, it’s good to sort of step back from all the details and all the claims for this or that and realize that beef is beef. It’s not fish, so don’t think that grass-fed beef is going to be a replacement for the omega-3 fatty acids in salmon. There’s a place for everything, and fruits and vegetables and whole grains are the stuff to concentrate on. To get into any more detail is really pushing the evidence.

PART III

THE BELIEVER: Why do walnuts make purple bread?

HM: Walnuts make purple bread because the skins of the walnut are full of tannins, and tannins are closely related to the pigments in red wine, the purple pigments. Essentially what happens when you bake bread is the dough is slightly acid and the conditions are just right to sort of leach out some of those compounds from the walnuts and then cause them to change color because of the change in the chemical surroundings. So what I have in my larder are red walnuts. It’s a new variety—well, new to California; I actually saw them about ten years ago in a test orchard. Instead of the regular tannins in the skin, these have the pigments already made. They’re bright red, sort of brownish, so they’re really striking looking. Because the tannins are premade they turn the bread more pinkish-red than purple.

PART IV

THE BELIEVER: In On Food and Cooking you include a lot of ancient recipes. Have you tried some of them?

HAROLD McGEE: I included one of these in one of the columns from last summer: ice cream, which we think of in very narrow terms nowadays. But there was a time when really crunchy ice cream was appreciated, and there were recipes that actually were designed to make the ice cream as crystalline and crunchy as possible. The recipe that I found was called “pin ice cream.” It’s supposed to poke into your tongue like pins. It’s really cool because we’ve all had ice creams that are grainy because they were sitting in the refrigerator for too long, but the really nice thing about this was you get this prickly sensation—it’s really cold because of the ice crystals coming in direct contact with you—but then as they melt, the cream that’s there begins to flow and so with each bite you get this kind of attack, and then soothing, instead of it being just soothing.

PART V

THE BELIEVER: How do you feel about fake sugar? I was reading about the Miralin Miracle fruit that was put into capsules in the mid-’70s, before it was banned.

HAROLD McGEE: I teach a course twice a year at the French Culinary Institute and one of the things we try to do is get some Miraculin, the stuff that goes in the capsules, for people to taste. There are lots of taste modifiers, things that change the way you experience other things, so I find those things really interesting in the sense that they tell you something about how complicated our experience of food is and how it’s not that you have a mixture of foods and you taste them all separately and together, but each one is sort of modifying the experience of the other. I find that fascinating, but the idea that you’re going to reduce your intake of sugar by putting something in your mouth that just makes everything sweet, that’s not what people are interested in sweetness for.