Factors that Affect Shelf Life
Almonds are relatively low-moisture, high-oil-containing nuts with a long shelf life when properly handled. Almond quality and shelf life can be influenced by three general factors: the product characteristics, the environment during distribution and storage, and the package. These factors interact in many ways to influence almond quality and to impact shelf life. Because of these interactions, shelf-life guidance for almonds must specify the product and the storage conditions.
Storage Conditions and Handling Practices
Storage for all almond forms in cool and dry conditions (<50°F/<10°C and <65% relative humidity) is recommended. The optimal goal of the recommended storage conditions is to maintain <6% moisture content, which helps preserve shelf life. A cool temperature of <50°F/<10°C is optimal, but a higher temperature that does not stimulate insect activity may work as well to control moisture migration (and also minimize lipid oxidation). Almonds are a shelf-stable nut that can have more than two years of shelf life when stored at the recommended conditions.
Storage Study Findings
Maintaining almond quality during long-term storage in ambient conditions is challenging in emerging export markets, such as China, which can have widely varying temperatures and relative humidities, depending on the season and region. A long-term-storage study published in the Journal of Food Science evaluated the shelf-life quality of almonds — raw kernels, blanched kernels and blanched-sliced kernels — stored for at least 18 months in ambient and controlled (including abusive) conditions.
A shelf study conducted by U.S. Army Natick researchers proved that various almond forms (raw, roasted, blanched, sliced) can have a three-year shelf life when they are packed in optimal packages (tri-laminated foil pouches under vacuum).
Almond shelf life factors, ABC Technical Summary, July 2014.
Long-term storage study of raw and blanched almonds, ABC research highlight, October 2012.
California almond shelf life: lipid deterioration during storage. Lin, X., et al. Journal of Food Science, 2012, 77(6):C583–C593.
Packaging is an important factor in almond quality and shelf life. The package can provide physical protection and, when needed, a barrier to moisture and/or oxygen and odors. Roasted almonds have very different packaging requirements than in-shell almonds.
Almonds are delivered to the handler for sizing, sorting and grading, and then stored in bins or other bulk containers under controlled conditions before being shipped or further processed.
For container shipments to overseas markets, in-shell almonds are generally packed in sacks. Naturally shelled almonds are packaged in cartons or fiber bulk bins, depending on the product and volume. Cut almond forms and roasted almonds require more protection against moisture and oxygen.
Cut almonds are generally packaged in cartons with a plastic liner or fiber bulk bins with a plastic liner — the plastic liner provides an important moisture barrier. Roasted almonds must be protected from oxygen (e.g., with nitrogen flushing and/or vacuum packaging). Roasted almonds processed in California are typically packaged in vacuum-packed foil bags and shipped in 25-pound (11.3-kg) cartons.