Any chef worth her salt (-cured yolks?) knows that transforming inexpensive, readily available ingredients into something special is the key to making memorable dishes. One of the best examples of this practice is the salt-cured egg yolk. The process is dead simple: Separate yolks, pack in salt and sugar, wait, rinse, dry in the oven, and use. Like a hard cheese, cured yolks can quickly add savory depth and complexity to a wide range of foods—soups, salads, pastas, and even meats.
Like all curing, this recipe relies on osmosis—water in the yolks travels through the yolk membrane to the surrounding cure. Our recipe, which cures for a week, yields dry, firm yolks that lose almost 50 percent of their weight in water, which greatly concentrates fat and flavor.
[Ed. note: for more information on and images from the salt-cured egg yolk process, see this page featuring Molly Birnbaum from America's Test Kitchen.]
1. Pulse salt and sugar in food processor until evenly mixed and slightly ground, about 14 pulses. (Alternatively, salt and sugar can be processed in blender on high speed until evenly mixed and slightly ground, about 30 seconds.) Transfer 14 ounces salt mixture to 8-inch square baking pan and shake pan to create even layer. Using whole, in-shell egg, make 12 evenly spaced ¼-inch-deep indentations in salt bed by pressing bottom of egg gently into salt mixture.
2. Working with 1 egg at a time, crack eggs, separate yolks from whites, and transfer yolks to indentations in salt bed. Carefully pour remaining salt mixture evenly over yolks. Wrap pan with plastic wrap and refrigerate until yolks are firm and dry throughout, 6 to 7 days.
3. Adjust oven rack to middle position and heat oven to 200 degrees F/93 degrees C. Set wire rack in rimmed baking sheet. Fill medium bowl with cool water. Remove yolks from salt mixture, brushing off excess, and rinse gently in water. Pat yolks dry with paper towels and transfer to wire rack. Transfer sheet to oven and bake until exteriors of yolks are dry to touch, 30 to 40 minutes.
4. Grate or thinly slice yolks and sprinkle on your favorite dishes, from pasta and risotto to roasted vegetables and buttered toast. (Cured yolks can be refrigerated in airtight container for up to 2 weeks.)