Google Books, the online digital library that allows you to search inside thousands of books, might be the most useful tool for journalists, fact-checkers and other researchers since the Dewey decimal system. I love my neighborhood library, and I still buy books, but sometimes I just need one quote from a weighty tome I would never buy and that my library wouldn't carry. Occasionally I find what I need in a book that I wouldn't have even thought to look in.
Now the evil geniuses at Google Labs have come up with another way to waste company time—I mean, conduct research. If you go to ngrams.googlelabs.com, you can enter two or more search terms and it will give you a graph comparing how frequently they appeared in books. It goes up only to the year 2000, but it's still a fun way to track food trends of the last century, at least by one measure.
For instance, compare "microwave" and "bake" between 1900 and 2000, and you see that "microwave" overtakes "bake" in the mid-1950s. Many of these early references probably have to do with other uses of microwaves than cooking (the first microwave oven was patented in 1941, but commercial models weren't popular until the 1970s), but there is a steep rise between the 1970s and the peak in the mid-1990s, when "microwave" starts to decline again. "Bake" hit a low around the era of Betty Friedan's The Feminine Mystique, but has been making a steady, if modest, comeback (like aprons).
Do you remember when you first heard of arugula? There's a good chance it was around 1984, the year it overtook iceberg lettuce in references in American English books. Since then it has risen sharply, while iceberg lettuce has wilted by comparison.
"Tofu" was nearly unmentioned until around 1970. By the mid-1980s it shot above flatlining "roast beef." Granola was also unheard of until 1970—not long after the Merry Pranksters introduced it to thousands of hungry, hungry hippies at Woodstock—but has risen steadily ever since, even briefly overtaking sushi for a few years around 1980, before raw fish made a flying leap and never came down.
It's also interesting to see how our names for foods has changed. "Pasta" was flat as a noodle until the 1970s, when it began to rise, climbing past "spaghetti" around 1982.
A three-way race between "pad thai," "moo goo gai pan" and "korma" shows Americans' changing tastes in ethnic cuisines: the Indian curry dish had peaks (in the late 1970s) and valleys (throughout the 1980s) as steep as the Himalayas, while the Chinese noodles went limp after their peak around 1994, and the Thai noodle dish, relatively obscure until the late '80s, shot past the others for a strong finish in 2000.
Can you think of any other good food-related queries? Report in the comments any interesting findings you discover.