Nuts are high in oil and vitamin B and turn rancid if stored badly or for too long. The best way to keep nuts is to refrigerate them in their shells, sealed in glass or plastic containers to avoid being tainted by other odours. Almonds and cashews are the hardiest while walnuts and pecans are most prone to deterioration in storage. When using almonds or other nuts, grind them in a food processor to the consistency of fine bread crumbs. Take care not to over-process, because nuts release their natural oils while grinding and you could end up with a nut butter!