Apparently, you can also make your own powdered sugar with potato starch and granulated sugar, processed in a food processor or coffee/spice grinder. Recipes I've seen call for one cup of granulated sugar and 1 teaspoon potato starch (Martha Stewart), or 1/3 cup granulated sugar and half a teaspoon potato starch (Epicurious). That's what I'm going to try for this recipe.

• Reply