My earliest exposure to soufflés was as a child watching television sitcoms, where a slammed door or other loud noise would cause it to deflate instantly. They looked like more trouble than they were worth, especially since they appeared to be nothing but an edible balloon.
I finally understood the soufflé's appeal when, as a teen or young adult, I tasted a chocolate one at a restaurant. It was a textural marvel, combining the fluffiness of a meringue on the inside with the chewy crust of the best brownies on top.
For my own experiment, I decided to try a semi-savory version, using an apple-cheddar soufflé recipe from Mollie Katzen's The Enchanted Broccoli Forest. It came out fine, I think, though it didn't seem to puff up as much as I expected. It tasted pretty good, but it lacked the "triumphant height" Alice Waters refers to in The Art of Simple Food.
There are a number of things that may have gone wrong, and they all have to do with the unique physical and chemical properties of eggs. In fact, it occurred to me that soufflés and meringues may be the original molecular gastronomy. Although the inventors of these dishes are unknown, it seems unlikely that they hit upon the recipes entirely by accident. Someone had to have been curious about what would happen if you beat an egg yolk for a really long time—mon Dieu, it turns into a thick foam!—mixed it with other ingredients and then baked it.
As for the science, Cooking for Geeks by Jeff Potter explains the chemistry of egg whites:
Since regions of the proteins that make up egg whites are hydrophobic—literally, water-fearing—they normally curl up and form tight little balls to avoid interacting with the water. But when whisked, those regions of the proteins are slammed against air bubbles and unfold, and as more and more proteins are knocked against an air bubble, they form a layer around the bubble and essentially trap it in the liquid, creating a foam that's stable.Potter and Waters both say a copper bowl is best for whisking whites, because trace amounts of copper ions interact with the protein in the egg whites and make a more stable foam that is easier to work with. Potter also suggests whisking by hand because, he says, "electric beaters won't work in as much air before the foam is set." I used my stand mixer, another cherished gift, so maybe that was part of the problem.
The enemy of a stable egg-white foam is oil—either from traces left in the bowl or little bits of egg yolk—because it interacts with the hydrophobic sections of the proteins and interferes with their trapping of the air bubbles.
Another hint that some cookbooks don't bother to mention is that egg whites will expand more quickly and easily if allowed to reach room temperature than when straight out of the refrigerator. I learned this the hard way, I'm embarrassed to admit, when I attempted the delicious-sounding chocolate malt ball cake from Baked: New Frontiers in Baking, by Matt Lewis and Renato Poliafito, for my mother-in-law's birthday. The cold egg whites never formed a stiff foam but, impatient person that I am, I used them anyway instead of starting over. The frosting they were used in was a gloppy mess.
The final variable that may have factored into my soufflé's low profile was oven temperature; the appliances that came with my kitchen are charmingly retro but not necessarily reliable. In On Food and Cooking: the Science and Lore of the Kitchen, Harold McGee informs that the higher the temperature of the oven, the higher the soufflé will rise, because the heat expansion will be greater and more of the moisture in the mix will be vaporized. However, he points out, this also means the soufflé will fall more quickly once it's taken out of the oven.
Another nugget McGee explains makes me wonder if my soufflé came out the way it was supposed to after all: A thick soufflé mix can't rise as easily as a thin mix. Since the recipe included grated apples, it may have just been too heavy to rise very high. Who knows, but I'll keep trying other soufflé recipes.
Ramekins, you're next.