Why Cashews Are Dried and Stored So Carefully

Water is what lets mould and spoilage take hold, so controlling moisture is the most important job after harvest. Freshly picked cashews contain a lot of it. Before anything else happens, the nuts need to dry.

After the nut is separated from the cashew apple, it's spread out in the sun and turned regularly. The Global Cashew Council says drying continues until the nuts in their shells reach about 8 to 10 percent moisture. Too wet, and they spoil in storage. Too dry, and the kernel can become brittle and break more easily during shelling.

Dry nuts are stored in conditions that are dry, cool and well ventilated, ideally dark. The Council gives targets of below 65 percent relative humidity and a temperature below 10°C for the best quality. Done properly, raw cashews in their shells keep well, which is why processing can continue through the year after the short harvest. See when cashews are harvested.

Once the nuts are shelled and peeled, the kernels are drier still, kept at no more than about 5 percent moisture. They need protection from strong smells, which cashews absorb easily, and from insects and pests. The Council also notes that methyl bromide should never be used to fumigate cashews, because it leaves an off-flavour.

Finished kernels are packed in clean, sealed packaging to keep out air and moisture. That's the same reason your roasted cashews come in a resealable pouch. For storing them at home, see how to store roasted cashews.

In a tropical country like Sri Lanka, the air is humid for much of the year, which makes careful drying and storage even more important. Nuts absorb moisture from damp air, so a pack left open on a kitchen counter softens and spoils faster than it would in a dry climate. That is why sealed packaging and a cool, dry spot matter so much, both for the farmer and for you.

Fresh cashews smell mild and buttery. If they smell sharp, sour or like old paint, or if they taste bitter or waxy, the fats in them have started to go rancid and the batch is best thrown away. Soft, chewy cashews that should be crisp have usually taken up moisture, and any sign of mould means they should not be eaten. Our guide to storing roasted cashews covers how to keep them fresh, including using the fridge or freezer for larger quantities.

Drying and storage are also about food safety, because damp conditions can allow mould to grow. Quality checks along the supply chain look for this, as we explain in how cashew quality and safety are checked. It is one more reason to buy from a producer you trust and to buy only as many cashews as you will eat in a reasonable time.

The longer a roasted cashew sits, the more it can lose its crunch and its freshness, however well it's packed. That's why we roast in small batches to order, so what reaches you is fresh. Browse the shop, or read how Sri Lankan cashews are roasted.