For some Americans, a trip to the ballpark isn't complete without the bright yellow squiggle of French's atop a hotdog. For the French, the slow burn of Dijon is a must-have complement to charcuterie. In the U.K., Sunday's roast beef is nothing without the punch of Colman's. Yet few realize that this condiment has been equally essential—maybe more so—for the past 6,000 years. In fact, the first spice that we know prehistoric humans used to pep up their dinners is none other than mustard. But why is the sale of mustard oil for consumption banned in the U.S., Europe, and Canada, despite the fact it’s used by millions of people around the world nearly every day? Listen in now for the answer to that mustard mystery and dozens more, including how mustard got its heat, and why we have caterpillars to thank for its particular taste profile.

When archaeologist Hayley Saul and her colleagues began investigating the food residues left behind in some particularly well-preserved cooking vessels from Mesolithic sites in present-day Denmark and Germany, she had no clue that the more than 6,000-year-old pots would contain definitive evidence of the first culinary use of spice in human history. "I think there's been a kind of assumption in general that, in prehistory, people were driven by the need to get a certain amount of energy, and that there was nothing particularly artistic about food practices," Saul told Gastropod. But, based on her analysis, it seems as though these Mesolithic communities were deliberately seasoning their meat and fish stews with a plant that is still widespread across Europe and Asia today: garlic mustard. By crushing the plant's mustard-flavored seeds and also adding its more garlicky leaves to their dishes, these Mesolithic chefs were carefully extracting the maximum flavor out of a plant that was otherwise not contributing much in the way of essential nutrients or energy. This episode, Saul shares her experience recreating these ancient meals—with surprisingly delicious results!

But how did mustard seeds get their heat in the first place? To understand the plant's evolutionary history, we speak with Patrick Edger, assistant professor of horticulture at Michigan State University, who describes an epic battle of chemical warfare between butterflies and brassica that took place over tens of millions of years and led to the popular condiment's potent sinus-clearing powers. Madhur Jeffrey, actress and author of what many consider the first popular cookbooks to introduce the West to Indian home cooking, explains why mustard is so beloved through the Indian sub-continent—and why current food safety rules in Europe and North America make it illegal for Indian chefs to use mustard oil outside of their home country. Finally, we visit America's one and only mustard museum, in Middleton, Wisconsin, where founder Barry Levenson helps us trace mustard's journey from ancient Egypt and Rome to the bright yellow squeeze-bottle, while exploring the basic chemistry that creates the different flavor profiles found in the mustard aisle today. All this, plus some unexpected mustard pairings: Dijon-dipped Oreos, anyone?

Episode Notes

Patrick Edger and Plant Warfare

Patrick Edger, assistant professor of horticulture at Michigan State University, loves mustard in all its forms. His 2015 paper on the butterfly-plant arms race traces the 90,000,000-year battle between butterflies and cruciferous vegetables that resulted in many of our most popular vegetables and spices, including mustard.

Hayley Saul's 6000-year-old mustard stews

Hayley Saul is an archaeologist at Western Sydney University, and one of the authors of the 2013 paper describing how the garlic mustard phytoliths she discovered in Mesolithic food residues at sites in northern Europe represent the oldest known culinary use of a spice in the world.

Madhur Jaffrey

Actress and author Madhur Jaffrey is perhaps the most famous writer of Indian cookbooks in the West; her books introduced American and European home cooks to the delight of cooking Indian food at home. Her first book, An Invitation to Indian Cooking, was published in 1973 and since then she has written over 15 cookbooks, now considered classics in their field, including, most recently, Vegetarian India.

National Mustard Museum

Lawyer Barry Levenson's passion for mustard led him to open the National Mustard Museum in 1992. It's filled with mustard memorabilia, and holds the world's largest collection of mustard.

Rose Eveleth

Finally, special thanks to Rose Eveleth, Gastropod fan and host of the podcast Flash Forward, for inspiring this episode with her mustard collection, her mustard questions, and her mustard pairing tips!

Transcript

For a transcript of the show, please click here. Please note that the transcript is provided as a courtesy and may contain errors.