Storing Maize So It Doesn't Spoil Before You Sell

The whole problem is moisture

Maize spoils for one reason: it is stored wetter than it should be. Everything else — weevils, mould, aflatoxin, weight loss — follows from that single failure, and every technique below exists to fix or maintain one number.

That number is 13% moisture content. Above it, mould grows. Below it, almost nothing does.

1. Harvest at the right time

Harvesting early to beat a thief or a rain is understandable and expensive. Grain harvested wet has to be dried by you, in the open, in the season when drying is hardest.

• Harvest when the husks are dry and the kernels are hard
• The black layer at the base of the kernel is the reliable sign of physiological maturity
• If you must harvest early, plan the drying before you cut, not after

2. Dry it properly

The goal is 13% or slightly below, evenly, without cracking the grain.

• Off the ground, always. A tarpaulin on bare earth draws moisture up into the grain overnight
• Use a raised platform or crib — airflow underneath is what makes the difference
• Turn the grain every couple of hours in the sun
• Bring it in before dusk. Grain left out overnight reabsorbs moisture and you lose the day's work
• Two to four days of good sun is typical for shelled maize spread thinly

Testing without a meter: bite a kernel. If it cracks cleanly and sharply, it is close. If it dents, it is too wet. Salt in a sealed jar with grain is a better test — if the salt clumps within ten minutes, the grain is still too wet.

Note: If you sell in volume, buy or share a moisture meter. It costs less than one rejected load, and rejection at the buyer's gate is the expensive outcome this article exists to prevent.

3. Shell and clean before storing

• Shell only when the grain is dry; shelling wet maize damages kernels and damaged kernels are where insects start
• Winnow out chaff, dust and broken grain — broken kernels spoil first and infest the rest
• Discard mouldy or discoloured cobs entirely. Do not store them "for the animals" in the same room

4. Choose the storage that matches your volume

• Hermetic bags — triple-layer bags that seal airtight. Insects inside suffocate within days, and no chemicals are needed. The best option available to most smallholders
• Metal silo — airtight, reusable for years, rodent-proof. Higher upfront cost, excellent for repeat storage
• Improved granary or crib — raised, ventilated, with rat guards on the legs. Good for cobs, less good for long storage of shelled grain
• Ordinary sacks in a room — the default, and the worst. If this is what you have, at least stack on pallets, away from walls, in a dry room

Hermetic bags are the change that transforms most smallholder storage, and they are the cheapest of the good options.

5. Keep it dry once it is dry

Storage is not a one-time act.

• Store in a room that does not leak and does not sweat
• Stack on pallets, at least 30cm off the floor and away from the walls
• Do not store next to fertiliser or fuel — grain takes on smell and buyers reject it
• Inspect monthly: open a bag, smell it, look for insects and for caking
• Rats are a storage problem, not a nuisance. Guard the legs and seal the room

6. Selling in the right month

The reason to store well is to sell late. Prices are lowest at harvest, when everyone is selling, and highest in the months before the next one.

• Track the price weekly rather than checking it when you need money
• Sell in tranches rather than all at once — it averages the price and reduces the risk of getting the timing wrong
• Factor storage losses into the comparison: a 10% loss wipes out a lot of price gain
• Clean, dry, well-graded maize attracts a premium from formal buyers that loose grain never gets

What to do this season

Dry to 13%, store in hermetic bags on pallets, inspect monthly, and sell in tranches over the lean months rather than in one load at harvest. Those four changes together are worth more than any single decision you can make about what to plant.