Whether you’re using pine nuts in salads or walnuts in cookie dough, a gentle toasting intensifies the nuts’ flavor and maximizes their crunchiness.
The simplest way to toast a lot of nuts is in a medium oven (325° to 375°F). Spread them in a single layer on a baking sheet with a rim (to keep wayward nuts from diving off the edge). If the nuts don’t fit in a single layer, use two pans. Stay close by, and give the nuts a stir every few minutes.
The nuts will be ready in 5 to 10 minutes; small nuts like pistachios will toast much faster than a batch of big Brazil nuts. You’ll know they’re done when they’re lightly browned and that comforting, nutty smell fills the air. Cut one or two in half; they should be an even pale brown throughout.
To toast just a handful of nuts, use a dry skillet over medium heat. The skillet method is faster since you won’t have to wait for the oven to heat up, but it also demands more attentiveness. You’ll need to shake and stir pretty constantly to avoid dark or burnt spots. A toaster oven is also convenient for small amounts.
If the nuts look and smell done but seem somewhat soft, don’t worry. Freshly toasted nuts dry and firm as they cool. They’ll also continue to brown slightly off the heat, so it’s better to remove them sooner than later. Be especially vigilant if the nuts will be added to a dish that requires further cooking: burnt nuts taste acrid and unpleasant.
Immediately transfer the nuts from the hot pan to halt their cooking. If you plan to chop the nuts in a food processor or pulverize them in a blender, first let them cool completely. When still warm, their oils are runny, and you may end up with nut butter.
Finally, toasted nuts have a shorter shelf life than raw nuts because the heat breaks down the nut oils, making them more prone to rancidity. Store toasted nuts, tightly covered, in a cool, dry spot, and use them within a week or two.