PW: You taught English literature at Yale and wrote your thesis on Keats. How did that background influence your science writing in On Food and Cooking?
Harold McGee: I initially went to Caltech intending to study astronomy or maybe chemistry, but discovered I was more interested in looking at the stars and thinking about what an amazing place the universe is than in working out equations to describe how much light gets through a dust cloud. I was convinced by the literature professors at Caltech that I should get a bachelor of science in literature. So I was able to stay and study literature, but also cherry pick the most interesting science classes. Then I went off to Yale to do graduate work. I loved teaching writing courses. I'd never thought about writing as something to approach systematically and analytically. So I started writing about what I was interested in, the science of everyday life, the things that are going on a little closer to us than the stars.
The line "the egg is the sun's light refracted into life" is very poetic.
That is the kind of stuff that I really love. Food is a wonderful subject because there are so many different aspects of it—from purely mechanical aspects to cultural and historical. But what I get the most satisfaction from is tracing those transformations—from the energy of the sun to the sunlight yolk on our plate.
Have you spent the last 20 years really writing, and rewriting, different portions of this new edition?
It's been more in the last 10 years. Not quite as bad as 20! I initially thought it would take about as long to rewrite it as it took to write it in the first place. I was mistaken. The American public in the intervening 10 years had gotten much more interested in food and much more knowledgeable about food, so there was more to explain.
How has food science changed since the first edition?
Our understanding of flavor and our perception of flavor is light years ahead of where it was 20 years ago. Back then, there were all these wacky ideas about our smell and taste buds and what certain combinations and permutations did—it was very theoretical.
You mention that when making caramel, the sugar molecules break down into hundreds of different flavor components, including some that are antioxidants—does that mean that caramel is better for you to eat than just straight table sugar?
[Laughs.] I think you could make arguments both ways. You'd have to, to answer it definitively, feed somebody a lot of sugar and a lot of caramel and see what happens. But caramel also creates other chemicals that cause DNA damage, so it's a mix, like everything in life. And where the overall balance ends up, I'm not completely sure. I think that I would not overindulge in caramel.
You've answered many of the questions you left unanswered in the first edition. What are some of the answers we won't find until the third edition?
Something I think that is still mysterious is gluten. Bread. There's a new theory about what's going on in gluten—how those protein molecules combine with each other and combine into this amazing, almost living superstructure. But the jury is still out on how it all really works. I really hope that that's in my book next time.