Artificial drying or drying with forced air is now used for pecans, speeding up the process considerably and eliminating molding problems. In-shell pecan kernels will darken under high humidity as a result of the tannic acid being dissolved from the shell lining. For vacuum or gas packed pecans, or those stored under freezing conditions, relative humidity control is not necessary. Lower temperatures usually result in longer storage life of nuts. Storage temperatures and predicted storage times of shelled and unshelled pecans are listed in table 1.
Pecan pieces have a shorter shelf-life than pecan halves.
This time reduction is in proportion to the surface exposure of the pieces. The greatest benefit of storing at low temperature is retention of fresh flavor, followed by color, aroma and texture. Because pecan meats absorb odors and flavors readily from the surroundings, a storage area free of odoriferous materials and commodities is necessary. Even faint odors of paint, wood, asphalt, vegetables, and other fruits can accumulate and appear stronger in the nuts than in the surrounding environment. Pecans stored in rat contaminated bags are subject to confiscation by the Food and Drug Administration.