Potato starch is the extracted starch from potatoes. The starch turns to a light, powdery, flour-like consistency once it has dried out, and it is a common ingredient that features in several recipes.

Potato starch is a versatile ingredient made by crushing potatoes to extract the starch. When you’re using potato starch, you’re using the dried and ground potatoes in the form of a fine powder.

If you’ve ever grated a pound of potatoes—say, for latkes—and soaked them in water until you’re ready to fry, you may have noticed some white, powdery stuff sinking to the bottom of the bowl. That, my ...