When it comes to no-bake oatmeal cookies, quick-cooking oats are the go-to grain of choice -- but not always. Just as in baking, making ingredient substitutions for stovetop-cooked desserts can be a mistake. In the case of no-bake oatmeal cookies, the proportions of liquids and fats to the oatmeal are important to achieve a cookie that firms up without baking, yet doesn't dry out.
Quick-cooking oats serve as a kind of middle ground between old-fashioned oats (rolled oats) and instant oats in no-bake recipes. Quick-cooking oats set up more quickly after being exposed to hot ingredients than old-fashioned oats and are less apt to dry out in typical no-bake cookie recipes than instant oats are. Quick-cooking oats come in smaller pieces than rolled oats and are more highly processed. As a result, they are considered less flavorful and chewy than old-fashioned oats.
Rolling with It
For no-bake cookies, use old-fashioned oats, also called rolled oats, interchangeably with quick-cooking oats, as long as the recipe specifies that either is acceptable. Use both in the same amounts in the recipe, but let the mixture sit longer after cooking when using old-fashioned oats. Both oatmeal types are more alike than instant oatmeal, which is more absorbent. Old-fashioned oats will produce a chewier cookie with larger oat pieces than quick-cooking oats.
Stirring the Pot
Follow recipes closely. In general, you'll combine milk, sweetener and a fat such as butter or oil in a saucepan, and bring it to a boil. After the mixture boils for the specified time, take the pan off the heat, and stir in the oatmeal and additional ingredients such as raisins. Drop the mixture by spoonfuls onto waxed paper. Do this immediately after mixing the oatmeal into the hot mixture -- in the case of quick-cooking oats -- or after 5 minutes of chilling if using old-fashioned oats. Let the cookies stand at room temperature or chill them, according to the recipe.
Going Against the Grain
While recipes often specify quick-cooking oats for no-bake oatmeal cookies, the recipe may be one that was developed in a test kitchen or to promote a specific product, such as instant oatmeal. If you try one of these recipes, use exactly the oat form specified. Oat flour and instant oats are more powdery and absorbent than the larger-sized oat types. A reputable recipe source will have adjusted fats and liquid accordingly.