Fermentation is the oldest food technology on earth. It happens in our guts, in the soil, in every cup of coffee and most restaurants still throw the juiced lime away. At Baldío, Mexico City’s zero-waste restaurant, Chris Locke has built an entire philosophy around that lime: a Korean-style raw syrup, a lacto-fermented powder for seasoning, a tapache, and finally a koji-based shoyu. Four products, zero waste, from something already used.

In this conversation, recorded inside Baldío’s production warehouse in Mexico City, Chris unpacks the three real drivers of fermentation — flavour, health, and waste reduction — and why most kitchens only chase one. He explains why the menu at Baldío functions like an ecosystem, where removing one dish breaks six others, why consistency is the wrong obsession for any restaurant working with small regenerative farms, and how 200 litres of surplus corn vinegar a week is pushing the project toward a retail product line.

A UK chef who built his fermentation practice in Toronto and a circular innovation kitchen in Melbourne before arriving in Mexico City and waited four months for a job that didn’t yet exist, Chris brings a rare cross-cultural precision to a practice most people still associate only with natural wine. Fermentation as a tool for closing loops, building shelf-stable products, and making the economics of zero-waste food actually work.