This story appears in the February 2019 issue of National Geographic magazine. Ketchup—that cheerful red sauce sold in handy glass bottles—first came on the American market in the 19th century.

Do you store ketchup in the fridge or in the cupboard? It’s a debate that has raged on unanswered – until now. The condiment manufacturing company Heinz has finally given its verdict.

The plot has thickened in the Justin Trudeau-Heinz ketchup controversy, as consumers with bottles that say "Product of USA" question how Canadian the popular condiment really is. Kraft Heinz took ...