Because of their high concentrations of fats, nuts have a tendency to go rancid. Heat, humidity, and light all hasten their spoilage. Be sure you shop for nuts in a store with a high turnover, especially if you buy from bulk bins. All nuts should smell sweet or “nutty.” A sharp or bitter smell indicates that the nuts may be rancid.
Storing walnuts is an important science. In general, whole nuts keep better than pieces, unprocessed nuts keep better than processed ones, and nuts in the shell keep better than shelled. Keep nuts in a cool place in a sealed container for up to four months. You can also keep them in the fridge for about six months and in the freezer for up to a year.
Dry-roasted nuts are always a good choice. Avoid those with added oil. Always check the labels: sometimes you’ll find added preservatives, corn syrup, or other sweeteners plus salt.
No-salt nuts are ideal, but if you can’t eat nuts without salt, it’s safe to enjoy them that way; just cut down on other sources of salt in your diet.