The history of tomato ketchup

John Brownlee recalls how a 17th-century fish sauce evolved into a patent medicine, a health hazard, and finally a $3bn industry. It's all about the bottle:

How bad were the ketchups of the time? In a study of commercial ketchups conducted in 1896, 90% of all ketchups on the market were found to contain "injurious ingredients" that could lead to death. … If there was one principle that Henry J. Heinz valued more than any other, it was purity and transparency. "It is always safe to buy the products of an establishment that keeps its doors open," Heinz once famously wrote. That every bottle of Heinz Tomato Ketchup sold is see-through is no accident. It's a design statement: purity through transparency.