English walnuts are the most widely available and come in many varieties some with moderately thick shells, others with shells so thin a tiny bird can crack them open. When buying walnuts in the shell, choose those free of cracks or holes. Walnuts in the shell can be stored in a cool, dry place up to 3 months. Shelled nutmeats should be refrigerated, tightly covered, up to 6 months. They can be frozen up to a year.
Walnuts are delicious in a variety of sweet and savory dishes and baked goods.
Oil made from lightly toasted nuts has a full, but not too assertive, flavor. For other types of oil, see chili, hazelnut, olive, peanut, sesame, and vegetable oil, and olive oil and vegetable oil cooking spray. Wasabi is used mainly with Japanese cuisine such as Sahimi, sushi, soba and tofu. It is often mixed with soy sauce. The French call this cooking technique bain marie .