From Bitcoin to puke-tracking: Walmart uses blockchains to monitor food

Commercial giant hopes distributed ledger tech speeds recall process, cuts illnesses.

As the potential of blockchains rattle beyond the financial realm, Walmart is the latest to try out the technology in the hopes that it can track food through the supply chain and pick out and recall tainted products.

As Ars has reported before, blockchain technology is essentially a ledger of data chunks—blocks—that link together using validation codes. Each block’s code references that of the one before it, creating an unbroken, sequential chain. Thus, all the blocks are preserved forever in the order in which they were added, providing a sort of built-in validation system—or as Ars previously described it, as a “souped-up audit trail”—locked from tampering. Better still, the chain doesn’t need to be stored in a master location but can instead be distributed among multiple computers still creating a linked record.

The technology was initially applied to secure money transactions, underwriting the rise of Bitcoin. But recently, there’s been a push to use it in other industries. In February, Ars reported that IBM was offering blockchain-as-a-service for businesses, particularly ones involving logistics, such as those in food supply. The idea is that food products could be tracked as they move from farms and factories to store shelves. Using tags and sensors, a product’s location, temperature, and other statistics could be recorded in a blockchain ledger at each step of the way.

As it happens, Walmart took IBM up on just that offer. In October, the commercial giant teamed up with IBM and Tsinghua University in Beijing to track pork in China as it moves from the farm to the shelves. Walmart is also tracking packaged produce in the US using blockchains. Walmart hopes that if anything goes wrong, such as the meat ships with contamination or spoils during delivery, affected batches can be quickly identified, tracked, and pulled from the reach of consumers.

“It gives them an ability to have an accounting from origin to completion,” Marshal Cohen, an analyst at researcher NPD Group Inc. told Bloomberg. “If there’s an issue with an outbreak of E. coli, this gives them an ability to immediately find where it came from. That’s the difference between days and minutes.”

For a retailer such as Walmart, which serves 260 million customers a week, an efficient tracking system also means the difference between pulling a few affected shipments and needlessly tossing products from hundreds of stores as a precaution.

This week, Walmart offered an update on the trial. “So far things are flowing smoothly and as expected," Frank Yiannas, vice president of food safety at Bentonville, Arkansas-based Walmart, told Bloomberg. If the trial continues to be successful, Walmart plans to expand blockchain ledgers to multiple foods in the US and China.