Vinegar serves several purposes when used in rib recipes, contributing to both the flavour and texture of the final dish. It adds a tangy and acidic element to the flavour profile of the ribs. This acidity can balance the richness of the meat and complement other sweet or savoury components in the marinade or sauce. The acidity in vinegar can also help tenderize the meat by breaking down its fibers. And lastly, in certain recipes such as this one, vinegar contributes to the caramelization process, especially when used in combination with sugars. This creates a flavourful crust or glaze on the ribs during cooking, adding depth and complexity to the overall taste.