Sanku fortified village flour by hiding the cost in bag sales

Tanzania's 2013 national fortification law required large industrial mills to add iron, folic acid and other micronutrients to packaged wheat and maize flour, but it exempted mills below a size threshold, because no dosing technology existed cheap or simple enough to fortify at that scale. That carve-out missed most of the country: maize supplies roughly 60% of the average Tanzanian's calories, and up to 95% of that flour is ground at thousands of small, informal village hammermills the law was never built to reach.

The obvious fix is to extend the mandate downward and require small mills to buy premix like large ones do. But a miller had no reason to comply: fortified flour costs more to make than unfortified flour once premix is added to his own bill, so buying it just meant raising his price against unfortified competitors selling from the next stall over, for a nutrient no customer could see or taste.

Bought the flour bags millers already needed, resold them at the same price, and used the margin to fund premix, so fortifying cost the miller nothing new.

Millers already bought flour bags weekly, so the bag margin was a reliable funding source.

Bundling premix cost into bag price made fortifying invisible to millers' books.

Dosifier sensors verified compliance automatically, removing need for inspections.

No price change meant no competitive disadvantage against unfortified rivals.

Fold compliance into a transaction the informal sector already makes, so the fix costs them nothing and needs no enforcement.

Helen Keller International's evaluation of the resulting rollout in Tanzania's Morogoro region found households consuming fortified flour daily rose from 0% in 2015, before Sanku began scaling, to 64% and then 96% within the year the bags-based model reached all 45 of its mills there — a combined 300,000-plus people in that district, and over 500,000 across Sanku's operations by late 2017. 92 in 2017.