Published September 1, 2011. From Cook's Illustrated.
What can 2 pounds of salt do to a potato that an oven can’t?
We were skeptical of the idea that burying a potato beneath a mound of salt could possibly improve on basic baking, especially since our research recipes used a variety of different methods.
We wanted to separate fact from fiction by developing a recipe that would use salt to intensify the potato’s flavor and make its texture moist and fluffy.
Our first step was getting the mechanics behind the method straight. Baking potatoes on a bed of salt in a covered pan works so well because it allows for moisture exchange between the salt and the spud. The moisture that escapes from the potato is contained in the covered pan and absorbed by the salt crystals, while some of that moisture is reabsorbed by the potato, helping to make its skin tender and its flesh light and fluffy.
With that knowledge, we began refining the details. We settled on baking the potatoes in a spacious baking dish (where the potatoes wouldn’t touch one another) atop a thick layer of either kosher or table salt. We started the spuds, covered, in a hot oven and then removed the foil and cranked up the oven temperature to ensure that the skins stayed tender. Brushing the potatoes with olive oil after uncovering them boosted the skins’ flavor and gave them an appealing glossy look. Adding a few rosemary sprigs and a head of garlic to the dish scented the potatoes with a piney aroma and gave us the means to whip up a quick roasted garlic-butter topping after the dish came out of the oven.list of recipes