Blueberries are as American as can be. The wild blueberry shrub (Vaccinium angustifolium) grows natively across the northeastern United States, where farmers tend both semi-wild blueberry patches and cultivated fields, producing more than sixty percent of the total global harvest. We Americans consume nearly all of our homegrown berries, plus another 190 million pounds of yearly imports.
If it weren't for an entrepreneurial woman named Elizabeth Coleman White, we might never have had commercially cultivated blueberries. Elizabeth was the oldest of four daughters born to Mary and Joseph White, Quakers who lived on a cranberry farm in New Jersey during the early twentieth century. She took an interest in the wild blueberries growing on her family's land and throughout the surrounding pine forest. At the time, blueberries were thought to be impossible to cultivate, but Elizabeth had ambitious ideas. After she read about the blueberry propagation research of Frederick Coville, a botanist working for the US Department of Agriculture, Elizabeth convinced her father to invite Coville to their farm. She paid a group of locals to seek out blueberry bushes that had desirable traits such as large berries and cold resistance. To differentiate the various plants, she named them after their finders. Coville began cross-fertilizing the best plants and, in 1916, just five years later, he and Elizabeth had achieved the nation's first commercial blueberry crop.
Since then, numerous hybrids have been created, some specifically designed for warmer climates. In Southern California, blueberries appear in farmers' markets from mid-May to late June. Look for plump fruits with taut skins. They should bounce around in their container when you gently shake it. If you arrive home from the market without devouring all of the indigo-colored berries, try baking this sweet, jammy blueberry crumble. I learned the recipe from my boyfriend, Graham, who made it during finals week when we were students at UC Berkeley. He didn't measure a thing. He simply tossed together a scoop of flour, half as much brown sugar, a pinch of salt, and a few pats of butter. The blueberries went into a baking dish with a sprinkling of sugar, and the topping was scattered over them. We ate the whole thing, straight from the oven, and it fueled us for our exams. For the following recipe, though, I did measure, testing the ingredient amounts until I found the ideal ratio of sweet fruit to crumbly streusel topping.
This crumble is one of the simplest and best summer desserts. It requires few ingredients other than ripe berries, and the whole thing comes together in a matter of minutes. If you prefer to leave out the oats, call it a crisp instead of a crumble. That's the difference between the two desserts -- did you know?
2½ cups (12 ounces) blueberries
1 tablespoon lemon juice
1 teaspoon lemon zest
¼ cup granulated sugar
1 cup all-purpose flour, plus extra for the baking dish
½ cup packed (4 ounces) brown sugar
1/3 cup oats
½ teaspoon Kosher salt
¼ teaspoon ground cinnamon
8 tablespoons (1 stick) unsalted butter, cut into small pieces, plus extra for the baking dish
½ teaspoon pure vanilla extract
Preheat oven to 375ºF.
Butter and flour the inside surfaces of a 9-by-9-inch (or equivalent) baking dish.
Combine the blueberries, lemon juice, lemon zest, and granulated sugar in a bowl, and set aside.
In another bowl, combine the flour, brown sugar, oats, salt, and cinnamon. Using your fingers, rub the butter into the flour mixture until there are no butter pieces larger than a pea. Add the vanilla extract and squeeze the mixture several times so that it forms clumps.
Transfer the sugared berries into the prepared baking dish. Sprinkle the streusel topping evenly over the berries. Bake for 30 minutes.
Serve the blueberry crumble with a generous scoop of vanilla ice cream.