Quick answer: Cashews and macadamias are spoiled by moisture, oxygen, heat and light. Export lots are vacuum packed and flushed with CO₂ or nitrogen to slow oxidation. In storage, keep nuts dry, cool and out of the sun; cold storage extends shelf life. After opening, reseal and use within a few weeks.
Why do nuts spoil?
- High fat content: cashew kernels are about 44% fat and macadamias about 76%. Fat exposed to oxygen and heat oxidises and turns rancid.
- Moisture uptake: dry kernels absorb water from the air, losing crunch and inviting mould.
- Insects: dirty stores or open packs attract moths and weevils.
Export packing
- Vacuum pouches with inert gas: multilayer pouches (often with a foil layer) are evacuated and flushed with CO₂ or nitrogen to remove oxygen.
- 50 lb cartons: two 25 lb pouches per carton for cashews; macadamias often in 11.34 kg pouches or as agreed.
- Tins: strong protection against impact and insects, still used in some traditional markets.
- Retail packs: jars, boxes and zip pouches with moisture barriers, 250 g to 1 kg.
Recommended storage
- Temperature: the cooler the better. A cool, ventilated store works for short periods; for long storage use cold rooms (about 5–10 °C).
- Humidity: keep it low and avoid damp areas. Store cartons on pallets, not on the floor.
- Light and odours: avoid direct sun; don't store next to strong-smelling goods (dried fish, chemicals, spices), as nuts pick up odours.
- Stock rotation: first in, first out (FIFO), tracking the production date of each lot.
Typical shelf life
- Vacuum-packed cashew kernels, unopened: typically around 12 months under proper storage.
- Macadamia kernels: more prone to rancidity because of their high fat content; keep them cool and use them sooner.
- In-shell macadamias (NIS): the hard shell protects the kernel, so they usually keep longer than kernels.
- After opening: reseal, keep cool or refrigerated and use within a few weeks.
The exact best-before date is printed on every lot.
How to spot spoiled nuts
- A rancid, paint-like or stale-oil smell, or a bitter taste.
- Soft, chewy nuts that have lost their crunch.
- Mould spots, white threads or signs of insects.
Don't eat nuts that show mould, as they may contain aflatoxins.
Frequently asked questions
How long do cashews last?
Vacuum-packed cashew kernels, unopened, usually keep well for around 12 months in a cool, dry place. Once opened, use them within a few weeks.
Should cashews and macadamias go in the fridge?
Yes. Low temperatures slow rancidity. Use an airtight container so the nuts don't absorb moisture or other food odours.
Why are export packs flushed with CO₂ or nitrogen?
The inert gas replaces oxygen in the pack, slowing fat oxidation and discouraging insects, so the nuts keep their flavour through long sea voyages.
Sources
- Association of Food Industries (AFI), cashew kernel packing specifications — afius.org
- USDA FoodData Central, cashew and macadamia composition — fdc.nal.usda.gov
VSAP vacuum packs export lots with inert gas and offers private-label (OEM) retail packs from 250 g to 1 kg. Contact us for detailed packing specifications.
— VSAP
