Once again we have a happy coincidence on our hands. Today’s New York Times food section just so happens to have a lengthy article on baking and fat. In it the author (Melissa Clark) recounts her adventures using various animal fats to make sweet pie crusts. Sound disgusting? Actually it isn’t. In fact animal fat, especially pig fat, especially leaf lard, has been one of the baking world’s most highly prized pie crust fats for hundreds of years.
What is leaf lard? Simply it’s the layer of fat that surrounds the kidneys and intestines of a pig. It’s prized as a baking fat in part because of its relative purity (compared to fat rendered form the flesh of the pig), but mostly because of its texture (firm) and flavor (mild yet full). In fact in the days before margarine was invented (around 1875) leaf lard was the number one butter alternative in the Western world.
But even after margarine (and ultimately shortening) was developed, leaf lard continued to be a go-to fat for serious pie bakers. The question is: why? Two reasons I can think of. First, texture. Fat from an animal has almost no water in it, and that’s extremely desirable from the standpoint of crust making. Water, even in small amounts, toughens crust. Mixed into flour it combines with the flour’s protein to create active gluten, which is the stuff that’s not only responsible for giving a pie crust a hard “bite”, it causes it to shrink up in the oven. Water is obviously also the enemy of crispiness, since crispiness and dryness are pretty much one and the same thing.
Butter, even though it tastes great, can contain anything up to 18% water, which is why French pastry chefs employ specialty fats like the buerre pâtissier I spoke of earlier. Zero water means zero sogginess which means lots of distinct, crisp and flaky layers in their croissants and puff pastry goods.
The other reason people like leaf lard is of course flavor. Not that people want their pumpkin pie to taste like pork chops, any more than bakers want their butter pastries tasting like lactic acid bacteria. Yet both can add a certain indefinable je-ne-sais-quoi if applied to foods in just the right way. And while I generally demure from making my pie crusts with all animal fat, there is much to be said for combining them, as Ms. Clark found out. Whether I’d try something like that with a layered dough like Danish I can’t really say. It’s actually never occurred to me before. But do yourself a favor the next time you’re in the mood for a culinary adventure. Go out and find yourself a little No. 1 leaf lard. I promise you won’t be sorry.