Good news this week for salad enthusiasts: Walmart, America’s largest retailer, will now require lettuce suppliers to use blockchain technology to track their produce from farm to shelf.

According to the open letter sent to suppliers of all leafy greens, end-to-end traceability information about the products will need to be captured and recorded in the Walmart Food Traceability Initiative by September 30, 2019, at the latest.

The change is intended to ward off events like the high-profile E. coli outbreak that occurred between March and June this year, resulting in five deaths and more than 200 instances of illness. Although the source of the affected romaine lettuce was eventually traced to the Yuma, Arizona region, supermarkets were initially unable to say exactly which of their suppliers were affected. Millions of heads of lettuce had to be destroyed, and there was a loss of consumer confident in lettuce from all regions. Better product traceability will presumably avoid such cases in future.

Walmart’s suppliers are directed to visit the IBM Food Trust network in order to begin the onboarding process (or, presumably, lose their standing as a supplier to Walmart, which would likely be financially ruinous for many of them).

According to the press release about the new requirement, using blockchain to replace the current tracking system of paper ledgers will reduce the time spent in tracing contaminated foods to their source from seven days to 2.2 seconds. Unsurprisingly, requiring suppliers to record and provide this information in a digital format is a huge improvement.

Blockchain aside, though, one could argue that the real innovation is in forcing producers to comply with a new, stringent, and most importantly digital reporting process for their products. Digital tracking procedures could have been mandated years ago if Walmart had wanted to do so.

IBM, the technology provider behind the Food Traceability Initiative, has invested heavily in the development of enterprise blockchain services, becoming a go-to player in the field. With a longstanding pedigree as a supplier of corporate IT systems, the company is well placed to take on projects which require a complete overhaul of a legacy technology stack (or paper document stack), and convince executives and shareholders of the importance of accurate data capture.

Whether blockchain technology is absolutely necessary to the project, though, is beside the point. It’s a technology and enterprise marketing trend that makes it cool to build accessible, auditable, and distributed digital ledger systems—and that, my friends, is what will keep your next salad safe.

Lead image via Flickr user Ben Brown.