What Spanish tapa consists of white anchovies marinated in vinegar and garlic?

The Spanish tapa of white anchovies marinated in vinegar and garlic is boquerones en vinagre.

This popular Spanish appetizer uses fresh anchovy fillets rather than the dark, salty anchovies commonly sold in tins. The cleaned fish are soaked in vinegar, which changes their flesh from brownish to white and gives them a bright, tangy flavour. They are then dressed with garlic, parsley and olive oil, and served cold.

Boquerones en vinagre is especially common in Spanish bars and restaurants, where it may arrive with bread, potato chips, olives or capers. It is often paired with beer or another refreshing drink. The vinegar marinade preserves the fish but does not reliably eliminate parasites, so Spanish food-safety rules require anchovies prepared this way to be frozen beforehand.

The main confusion is with anchoas en salazón, which are anchovies cured in salt and usually packed in oil. Those anchovies are darker and much more intensely savoury. Boquerones are milder, fresher-tasting and recognisable by their pale white fillets.