Cassava: the root that has to be handled right

Cassava feeds more people in West Africa than any other crop, and almost nobody eats it the way it comes out of the ground. It is soaked, fermented, grated, pressed, dried, fried, pounded — sometimes several of those in sequence — before it reaches a plate.

That is not fussiness. Raw cassava is mildly poisonous, and every one of those steps is a way of removing the poison. Generations worked this out by observation long before anyone could explain the chemistry, which is a quietly remarkable thing.

What is actually in it

Cassava root contains compounds called cyanogenic glycosides — mainly one named linamarin. On their own they are harmless. But when the root's cells are damaged — cut, grated, chewed — an enzyme in the plant meets them and releases hydrogen cyanide.

The plant almost certainly evolved this as a defence against being eaten. It works on most animals. It did not work on us, because we learned to take it apart.

There are two broad kinds. Sweet cassava is low in these compounds and needs only proper peeling and thorough cooking. Bitter cassava carries far more — and it is often the one that gets planted anyway, because it yields more, resists pests, and is less likely to be stolen from a field.

Every traditional process is a removal process

Look at what the methods have in common and it becomes obvious.

• Peeling. Most of the compound sits in the peel and in the layer just beneath it. Peeling generously removes a large share before anything else happens.
• Grating. Breaking the cells open on purpose lets the enzyme meet the glycosides and release the cyanide while it can still escape — rather than later, inside a person.
• Soaking and fermenting. Days in water lets the compounds break down and leach out. This is the step behind lafun and behind traditional fufu, and it is why both smell the way they do.
• Pressing. Squeezing out the liquid takes the dissolved compounds with it.
• Drying and frying. Heat and air drive off what remains. The frying of garri is the last gate.

Garri passes through nearly all of these, which is part of why it stores so well and travels so far.

What this means when you are buying

You are almost never in danger from cassava bought and prepared normally. The processing is thorough, the people doing it have done it a long time, and the traditional methods are genuinely effective.

The real risk shows up at the edges: cassava rushed through processing, cassava prepared during a food shortage when nobody could wait, or bitter cassava treated as though it were sweet. Where those things happen at scale, the results are documented and serious — a paralysing condition called konzo, and iodine deficiency made worse.

The practical version is short: buy from people who know what they are doing, and be wary of cassava products that look like they skipped a step.

What it gives you, and what it does not

Cassava is almost pure carbohydrate. It is filling, it is cheap, it stores, it grows in poor soil and it survives drought — which is exactly why so much of the region depends on it.

But it is very low in protein, and low in most vitamins. A plate of swallow on its own is a plate of starch.

This is why cassava is never served alone, in any culture that eats it. The soup beside it is not a garnish and it is not optional — it is the half of the meal that carries the protein, the fat, the iron and the vitamins. Eat the swallow and skip the vegetables and you have eaten energy and nothing else.

The tradition already knows this. It is worth knowing it deliberately.