#757 2016 · Sanku / Project Healthy Children (Felix Brooks-Church) · Public health / food fortification

Tanzania's flour-fortification law only reached the country's few big mills — so a nonprofit built a machine that lets thousands of small village mills fortify for free, without changing anything the miller does

the problem

A fortification law couldn't reach the small mills serving most people

background

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.

what everyone would do

The standard fix for a fortification mandate that misses small, informal-sector mills is to extend the law to cover them and require them to buy premix like large mills do — but no miller will voluntarily raise his own cost for an invisible nutrient his customers can't see, taste, or pay more for.

what they saw

Brooks-Church's team saw that the barrier wasn't the miller's willingness or the government's law, it was that fortification had always been sold as an added cost layered onto an existing purchase. Millers already bought flour bags from someone every week; if the premix could be funded from the margin on a transaction the miller was making anyway, fortifying would never appear on his books as a new cost at all.

the move

Sanku, founded by Felix Brooks-Church, built an IoT-connected 'Dosifier' that bolts onto a small mill and automatically meters micronutrient premix into flour during the milling the miller was already doing. To remove the miller's cost objection entirely, Sanku restructured the transaction: instead of selling millers premix, it buys the flour bags millers already needed in bulk, resells them at the same price millers were already paying, and uses the margin to fund the premix — so fortifying costs the miller nothing beyond continuing to buy bags.

why it works

By selling bags in bulk below what millers were already paying retail, and using that spread to cover premix instead of charging for it separately, Sanku turned a cost millers had every incentive to skip into a bundled input indistinguishable from the bag itself. The miller's price and behavior never change, so there is nothing to persuade him of and nothing for a regulator to enforce — the dosifier's own sensors track flour volume against premix dispensed, so compliance is verified automatically rather than inspected.

the payoff

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. Sanku's own tracked annual cost per person reached fell from $1.47 in 2016 to $0.92 in 2017. A 2023 peer-reviewed study by the US CDC, Helen Keller International and the Tanzanian government, surveying 711 Morogoro households, independently confirmed packaged maize flour had become a routine purchase across the region.

where it breaks

The model depends on an intermediary like Sanku being able to buy bags at genuine bulk discount and being subsidized enough to absorb dosifier hardware costs upfront — the 2016-17 numbers show cost-per-person still falling from philanthropic support, not yet self-sustaining from bag margins alone. It also only works for a staple ground through a physical mill a device can be bolted onto; it has no answer for foods fortified or consumed in forms that never pass through a chokepoint like that.

what came after

Morogoro's local government passed a bylaw requiring all flour sold in the district be fortified after Sanku demonstrated small mills could comply at no cost. Brooks-Church became a 2021 Rolex Award for Enterprise Laureate; by then Sanku was working with roughly 1,500 mills across Tanzania, Kenya and Ethiopia and reported reaching close to 25 million people, on a stated goal of 100 million by 2030.

references

[1]A conversation with Project Healthy Children/Sanku, October 24, 2017GiveWell, 2017files.givewell.org
[2]Coverage, Apparent Consumption, and Monthly Use of Packaged Maize Flour in Morogoro Region, TanzaniaFood and Nutrition Bulletin / US CDC, 2023stacks.cdc.gov
[3]Battling Malnutrition One Fortified Bag of Flour at a Time, Felix Brooks-Church, 2021 Rolex Awards LaureateRolex, 2021newsroom.rolex.com