Which trade route brought the Portuguese frying method that led to tempura?

The Nanban trade brought the Portuguese frying method that helped lead to tempura.

“Nanban trade” describes the commercial and cultural exchange between Japan and European traders, especially the Portuguese, from the sixteenth century. Portuguese ships and missionaries reached Japan in the 1540s, and Nagasaki became a major center of this contact. Along with goods, religion, vocabulary, and technology, the exchange introduced cooking practices involving flour and deep-frying.

One often-cited influence is peixinhos da horta, Portuguese green beans coated in batter and fried. Portuguese Catholics ate such foods during Lent and other fasting periods when meat was restricted. Japanese cooks adapted the technique to local ingredients, especially seafood and vegetables.

The route and the final dish should not be confused. Nanban trade names the exchange network; it was not itself a recipe. Tempura was subsequently transformed in Japan, particularly in Edo, where vendors developed a lighter batter and served fresh seafood with dipping sauce. Thus the Portuguese influence explains the method’s arrival, while Japanese cooks created the form recognized today.