Walmart cites the recent romaine lettuce Escherichia coli outbreak--and the difficulty in tracing where consumers and retailers’ lettuce had come from--as the impetus for this request.

“But it was difficult for consumers to know how to determine where their lettuce was grown,” says Frank Yiannas, vice president of food safety at Walmart.

“None of the bags of salad had ‘Yuma, Arizona’ on them,” he said. “In the future, using the technology we’re requiring, a customer could potentially scan a bag of salad and know with certainty where it came from.”

Walmart plans to use the power of blockchain to speed up identifying, researching and reacting to food safety situations. The traditional paper-based methods that many farms, packing houses, and warehouses still use can take up to 7 days to determine where a single food product originated.

Walmart’s suppliers are expected to be able to implement blockchain technology within a year.

Just last month, Frank Yiannas joined the Food Safety Matters podcast to discuss Walmart's food safety initiatives, including the use of blockchain. Listen to that episode now.