March 10th, 2016
Take a non-reactive container—a glass casserole dish is good for this—and cover the bottom of the dish with a deep layer (about 3 inches/7.5 cm) of your preferred salt mixture. You can use only salt, or a 60:40 sugar to salt blend. Get a little creative and use a bit of truffle salt, chili- or herb-infused salt, or even a smoked salt. Or how about vanilla sugar?
Use the back of a teaspoon to make little depressions for the yolks to sit in. Separate as many eggs as you want to cure, placing each yolk in its own dish, then very gingerly tip the yolks out of their dishes and into the indents in the salt. Cover with another deep layer of your salt mixture and place them in the fridge, uncovered, for about 7 days.
For each yolk, prepare a double-layered 6-inch (15-cm) square of cheesecloth and a 12-inch (30-cm) length of kitchen twine. You’ll also need to figure out a method for suspending the yolks in the fridge—I use a wire egg basket, natch!
After 7 days, you’ll need to dig the yolks out, and here you’ll want to be as careful as an archeologist digging up dino bones; the yolks are still fragile. Gently brush off the excess salt using a pastry brush, then set each yolk into the centre of a cheesecloth square. Pull the corners of the cheesecloth up around each yolk like a little coin purse, and cinch shut with a length of kitchen twine. Suspend the bundles in the fridge and there they will stay for about 3 more weeks, until they are almost rock-hard. Wrapped in cheesecloth and suspended for air circulation, the preserved yolks will keep for several months in the fridge.