Raw shelled peanuts usually keep their quality for several months to around a year when stored cool, dry and free of pests. In cold storage they can keep longer. In a hot, humid warehouse they can go rancid, mouldy or infested within a few months.
There is no single shelf life. It depends on the crop, the moisture at packing, the packing type and above all on storage conditions. Agree a best-before period with your supplier based on how you will store the goods.
What shortens shelf life
- Rancidity: peanuts are rich in oil, which oxidises with heat, light and oxygen and gives stale or painty flavours.
- Moisture: kernels that pick up moisture can grow mould, which can also raise aflatoxin.
- Insects: storage pests such as moths and beetles can infest kernels, especially in warm conditions.
- Odours: peanuts absorb smells from chemicals, fuel or strong foods stored nearby.
- Damage: broken and split kernels oxidise faster than whole kernels.
How to store raw peanuts
Store in a cool, dry, well-ventilated warehouse. Keep bags on pallets, away from walls and off the floor. Avoid direct sun and big swings in temperature, which cause condensation. Keep peanuts apart from chemicals and strongly scented goods.
For long storage or warm climates, cold storage helps a great deal. Many buyers hold peanuts chilled and at controlled humidity. The exact set points depend on how long you hold the goods and your warehouse, so take advice from your cold store. Rotate stock first in, first out.
When you take peanuts out of cold storage, let them warm up before opening the bags. Opening cold bags in warm, humid air causes condensation on the kernels.
Shelled, in-shell and blanched
In-shell peanuts usually keep longer than shelled kernels, because the shell protects the kernel. Blanched kernels have lost their skin and usually keep for a shorter time, so they are often vacuum or nitrogen packed. Roasted peanuts have the shortest life unless packed with low oxygen.
Packing makes a big difference. The choice between jute, woven bags and vacuum packs is covered in how peanuts are packed for export.
Tests that show ageing
Ask for peroxide value and free fatty acid results at shipment, and test again if you hold stock for a long time. Rising values mean the oil is oxidising. Check moisture, insect damage and aflatoxin too. Typical limits for each depend on your product and market, so set them in your spec. Moisture limits for the voyage are discussed in what moisture level is safe for shipping oilseeds.
Where we come in
We check moisture, crop year and storage at the processor before your lot is packed, and ask for peroxide value and free fatty acid on the shipping sample. That way you start your shelf life with fresh, dry kernels. Ask for a free sourcing review to plan it.