When nuts are stored at room temperature they can go rancid because they are protein-rich and loaded with heart-healthy fats. Because of this high fat content it is best to store nuts in a resealable plastic bag in the freezer. These will keep for up to one year (date the bag so you can keep track). If you buy nuts in bulk, portion them into several bags so you don’t open up the same bag every time you need just a few.