Nine thousand years ago, the people of the Balsas Valley began transforming a wild grass with five inedible kernels into the most productive crop in the Western Hemisphere. What they built over five millennia of careful, intentional agricultural work is the most dramatic plant domestication in recorded history. What they discovered afterward — a preparation technique that unlocked the nutrition locked inside the grain — is the most important food discovery most people have never heard of. The three thousand years between that discovery and Europe's decision to ignore it cost hundreds of thousands of lives. The American Season opens where America's food story actually begins. Not with the Pilgrims. Not with colonial tobacco. With corn.

Seven thousand years, six hundred flavor compounds, and the full affirmative health case for the most complex food humans have ever made. The dairy series finale — and the Season One closer. Cheese earned this episode.

Part Three of the dairy series — milk was the origin, butter was the vindication, yogurt is the fermentation. The science here is less contested than most of what this show covers, which is its own kind of relief. The evidence for yogurt is consistent, the mechanisms are understood, and the food has ten thousand years of safe human use behind it.

What the American food industry did to it in the second half of the twentieth century is a separate conversation. We'll get there.