Consumers around the world enjoy - and expect - a consistently high-quality product in California almonds. Stockpiling is a key component of ensuring food safety. Read below for tips and resources to help maintain and exceed the expectations of California almond consumers.
Stockpiled almonds can be a food safety risk if not properly managed. The combination of the moisture in the crop and the condensation that occurs under tarps favors the growth of Aspergillus mold, which produces aflatoxins.
The orientation and shape of the almond stockpile can help minimize the risk of Aspergillus mold growth, as can these additional practices:
- Place stockpiles on a firm surface, preferably one that is slightly raised to encourage moisture to run off rather than puddle around the edges.
- Orient the long axis of piles from north to south as much as possible. Condensation and mold growth tend to be worse on the north side of piles when the long axis is oriented from east to west.
- Smooth the tops of the piles to help minimize the concentration of moisture from condensation.
- Use a white-on-black tarp, which is best at minimizing temperature fluctuations that lead to condensation and mold growth. Clear tarps allow the highest temperature fluctuations, but may be used on dry, in-hull product. White is intermediate between clear and white-on-black.
- If piles are stacked too wet, open up the tarps in the daytime, when the relative humidity is lower, and close them at night, when the relative humidity is high.
- Monitor relative humidity (rH) during the storage period, paying particular attention to the outside of piles, where there can be significant temperature fluctuations, condensation on tarps and moisture accumulation. If the total fruit (in-hull almond) moisture is more than 9%, the rH may exceed 65% in the pile, which is the maximum rH acceptable for almond storage.
In addition, stockpiled almonds should be kept in a storage area that is maintained to ensure cleanliness. Monitor regularly to keep pests away from stockpiled almonds.