Cassava is the great insurance crop of the tropics — it waits patiently in the ground through drought, pests and hard years. But fresh roots begin spoiling within forty-eight hours of harvest, and that clock is the reason so much cassava is wasted or sold for pennies. Flour changes the arithmetic completely. Well-made cassava flour keeps for six months, weighs a quarter of the fresh roots it came from, and sells into a market that grows every year as bakeries blend it with imported wheat.
The catch is in the phrase well-made. There are two products that come out of a cassava mill: a white, clean-smelling flour that bakers pay a premium for, and a grey, sour, streaked flour that traders take only at a discount. The difference is not equipment. It is speed and cleanliness, and both are free.
The twenty-four-hour rule
Everything about quality cassava flour follows from one fact: the moment a root is lifted, enzymes begin browning it and micro-organisms begin fermenting it. Traditional soaked products like lafun or fufu use that fermentation deliberately. High-quality cassava flour — the kind bakeries want — does not. It must go from soil to dry in twenty-four hours, and everything in the process is organized around beating that clock.
So plan backwards. Do not harvest more than you can peel, grate and press before nightfall. A household team of three can comfortably handle 100–150 kg of fresh roots in a day; a small cooperative with a motorized grater can do a tonne.
Step by step
1. Harvest and peel — same morning
Choose roots 9–12 months old from a sweet (low-cyanide) variety. Peel with knives, removing both the brown skin and the pinkish layer beneath it, and drop the peeled roots straight into a tub of clean water so they never sit exposed to air. Wash off every trace of soil — grit is the flaw millers complain about most.
2. Grate fine
Grate the roots into a fine mash. A motorized grater does a sack in minutes; a hand grater made from punched roofing sheet works for household volumes. The finer the mash, the faster it presses and dries, so do not rush this step.
3. Press hard, press fast
Pack the mash into clean woven sacks and press out the juice. A screw press is ideal; stones piled on a board over the sacks work too, though more slowly. You are aiming to get the mash from roughly 65 percent moisture down to about 45 percent — the point where a squeezed handful crumbles instead of dripping. This is also the step that removes most of the remaining cyanide compounds along with the juice, so press thoroughly.
Good pressed cake is bright white and smells of nothing. If it smells sour, fermentation has started — the flour will grade lower. Next batch, move faster between grating and pressing: that gap is where sourness is born.
4. Crumble and dry the same day
Break the pressed cake through a coarse sieve into fine crumbs and spread them thinly — a finger's depth at most — on black plastic sheeting, raised mesh trays or clean mats in full sun. Stir every half hour. In good sun the crumbs dry to a crisp rustle in five to eight hours. They must be fully dry before dark; crumbs that spend a humid night half-dry turn grey and musty. If the sky threatens, get the trays under a roof with air moving over them rather than gambling.
5. Mill and sift
Dry crumbs go to any local hammer mill — the same one that grinds maize. Mill fine, then sift through a fine-mesh sieve. What stays on the sieve goes back through the mill. The finished flour should be uniformly white, silky between the fingers, and pass entirely through the sieve.
Storage and selling
Pack the cooled flour into food-grade plastic-lined sacks or clean containers with tight lids, and store them off the floor in a dry room. Properly dried flour (under 12 percent moisture) keeps six months without trouble. Label sacks with the date — buyers trust a producer who can answer "when was this milled?" without hesitation.
Five kilograms of fresh roots become roughly one kilogram of flour. That kilogram sells for three to four times the price of the roots that made it — and it will still be sellable half a year from now, which the roots never were.
The bakery market is the one to court. Many bakeries now blend 10–20 percent cassava flour into bread and pastry flour, and they buy on consistency: same whiteness, same fineness, same dryness, sack after sack. Master the twenty-four-hour rhythm and that consistency is exactly what you have to sell.