Walmart Blockchain and Romaine

What if we had a better way of tracking our food from farm to fork? One that allowed us to see, at the tap of a button, all the different stops that a particular item of food has passed through to get to where it is? I have three words: Walmart Blockchain and Romaine.

Walmart thinks that they might. They sent out a letter to their suppliers of leafy greens on September 24th announcing a bold new initiative: in partnership with IBM, they’re attempting to get their whole supply chain on board with the blockchain. The encrypted public ledger made famous by Bitcoin isn’t just about creating cryptocurrency markets that consume as much energy as Belgium; the blockchain can be used to create secure digital records for all sorts of things. Including lettuce.

Walmart and Blockchain

To understand why Walmart is jumping on the blocktrain (sorry), we need to think back to June of this year, when more than two hundred people fell ill with E. coli after eating tainted lettuce. Five lost their lives. It was the largest outbreak of the pathogenic bacteria in more than a decade, and it sent investigators scrambling to determine a starting point.

They didn’t have much luck. Traceback work led them not to a particular supermarket, distributor, or farm, but instead to a canal in Yuma, Arizona. They found a genetic match for the E. coli behind the outbreak in the canal, and they had the notion that the E. coli had been transferred to lettuce from the canal via irrigation. What they weren’t sure of was where the E. coli had gone, exactly – what farms it had or hadn’t ended up on.

A Warning, But No Recall: More Info Needed

So, the CDC and FDA ended up issuing a warning to consumers asking them to stay away from lettuce from Yuma, Arizona. It was a broad, non-specific measure, and it generated a lot of confusion. It’s not always so easy to tell where the lettuce was grown by picking it up and examining it at the supermarket. Consumers didn’t really have the information that they needed to make the informed choices necessary to avoid the outbreak, and struggled to figure out what lettuce was from Yuma. That was made all the more difficult by the fact that Yuma supports a billion dollar lettuce industry and is responsible for some 90% of leafy greens in the United States during the winter.

That brings us back to Walmart, and back to the blockchain. The hope is that blockchain technology will prevent situations like the Yuma lettuce confusion in the future. It’s a relatively simple idea: without blockchain tech, the process of verifying each step that lettuce passes through on its way from the farm to the fork is a patchwork one. Some places keep paper records; some of them have elaborate electronic databases. Not everyone is on the same page, and not everyone is recording the same information. If someone’s cutting corners at some point along the line, it’s relatively easy for them to do so, and it’s difficult for the other parties involved to figure out that there’s malfeasance going on.

The Process

The blockchain takes this patchwork of records-keeping processes and centralizes them in a single system. The different parties involved along the supply chain for the lettuce are connected by a decentralized digital network. The parties are constantly checking in with one another, and everything that they do on the network is visible to the other nodes. Not only is it visible; it’s recorded by design. Actions taken by the nodes are stored in an encrypted digital ledger that’s shared between the network; the ledger is divided up into blocks, and encrypted in such a way that individual actions or the blocks themselves can’t be faked or altered without an enormous amount of computing power.

For Example, Let’s Take the Romaine Lettuce Outbreak

It can be a bit hard to get your head around, so we’ll attempt to explain it with lettuce. There are several different actors in the lettuce network: farmhands, field supervisors, the people who clean and wash the lettuce, delivery truck drivers, health inspectors, and Walmart employees of various sorts.

Walmart assembles a list of everything that needs to happen to a head of lettuce before it hits store shelves and gives all of these different actors a smartphone loaded with an app that allows them to add to the blockchain. Each time one of these actors does one of those things – sprays lettuce down with pesticide, checks it for bugs, picks it, washes it, packs it into a crate, loads that crate onto a truck, drives that truck across the country, delivers the lettuce to the store, verifies the delivery to the store, puts the lettuce on store shelves – they use their blockchain app to record and verify that they did indeed do the thing.

The Solution?

Each record that’s made along the way is seen by all the different nodes of the network (in this example, the smartphones distributed by Walmart). Hopefully, the new system provides more clarity when it comes to the provenance of leafy greens. That should (theoretically) translate into more efficient recalls and tighter food security. There’s still a lot of human error, of course: at this point, it looks like a lot of the data recorded in the blockchain will involve workers ticking off boxes on checklists, which can easily be faked or messed up. In a globalized world of food, however, fresh ideas and novel solutions that shed some light on the supply chain are badly needed. This seems to be a step in that direction.

It’s All About Trust

About 90% of greens are grown in the Yuma region of the United States in the winter. After the E. coli romaine outbreak, many consumers still do not trust Yuma farms. According to one farmer, “We have to get our consumer confidence back, and, hopefully, in time for our fall harvest beginning in November.” Maybe, just maybe, blockchain could be their answer.

By: Sean McNulty, Contributing Writer (Non-Lawyer)