Are all new potatoes small? Are all small potatoes new?
New potatoes are potatoes harvested before the skin sets so that they have delicate skins. But even after reading the definition, we were shaky on the details. What does it mean to “set” the skin? Are all new potatoes small? Are all small potatoes new? Can we use new potatoes in the same ways that we use regular potatoes?
For help, we called the United States Potato Board, a marketing organization for the potato industry. A spokeswoman explained that setting the skin is the process of cutting down the vines of the potato plants but leaving the tubers in the ground for two weeks to a month. During that time, their skin becomes thicker and better able to protect the spuds during storage and transit. New potatoes don’t get that time to toughen up; they go straight to market with delicate skins that the spokeswoman described as “flaky.” If you rub the skin of a new potato with your thumb, she said, it will rub right off. The potatoes that are harvested this way are almost always small. In most of the country, new potatoes are available in late summer and early fall. Because they are moist and sweet, they aren’t well suited for frying: They’ll brown too quickly and won’t get as crispy as ordinary potatoes.
Are all small potatoes you find at the market new potatoes? No. If it’s not the harvest season, chances are they are just smooth-skinned varieties that have been harvested while still small. Some varieties, such as rough-skinned russets, are never sold as new potatoes; you’re not looking for moist and creamy in russets anyhow. If you’re making a recipe that calls for new potatoes but they aren’t in season, substitute a small, thin skinned variety like fingerlings.
THE BOTTOM LINE: New potatoes are sweeter, moister, and thinner-skinned than ordinary small potatoes. You can substitute fingerlings and other small, naturally thin-skinned varieties.