Blockchain: from the tech industry to the food industry, it seems like all anybody’s talking about anymore. The technology’s role in food supply chain traceability has been a hot topic for the past year or so, and now it’s starting to transition from the realm of discussion to reality.

Walmart has announced that by September 2019, it will require all suppliers of leafy greens to upload data about their products to the blockchain. This is part of a year-long project the mega-retailer has with computer company IBM, as well as food companies. The goal is to make it easier to read the history of leafy green products, stretching back to the farm and all the way to the supplier’s doorstep.

Walmart doesn’t expect the process to be an undue burden on suppliers. The technology is not complicated to use, it says.

“IBM will offer an onboarding system that orients users with the service easily,” said Walmart spokesperson Molly Blakeman. “Think about when you get a new iPhone — the instructions are easy to understand and you’re quickly up and running. That’s the aim here. Essentially, suppliers will need a smart device and Internet to participate.”

It makes sense that U.S. retailers would be interested in tracking leafy greens considering this year’s major E. coli outbreak associated with romaine lettuce. It took investigators months to identify a source of contamination, because the supply chain with this product was a particularly complicated web. With a transparent blockchain system, traceback data could be loaded and analyzed in just seconds.

“We felt the one-step-up and one-step-back model of food traceability was outdated for the 21^st century,” said Walmart Vice President of Food Safety Frank Yiannas. “This is a smart, technology-supported move that will greatly benefit our customers and transform the food system, benefitting all stakeholders.”

Hold up — what are these blocks, and why are we chaining them?

Blockchain systems are essentially digital logbooks. The technology is a secure record-keeping system that operates over the Internet. The Economist describes it as “a shared, trusted, public ledger that everyone can view, but which no single user controls.”

Blockchain can be used to monitor a continuously growing list of records that are tied together in a digitally encrypted format. It’s expected to be vastly popular as a food supply chain documentation system in the future, and it’s also the technology behind cryptocurrencies like Bitcoin.

Many in the industry expect that within a few years, blockchain could totally change the way we label food products, with customers possibly being able to scan the entire history of their food onto their smart devices. And as the food supply chain continues to become more globalized, detailed traceback documentation will only become more and more important.