Acidify?

To add acid such as lemon juice, vinegar or verjuice to a culinary preparation. A process of adding an acidic solution such as vinegar, wine or lemon juice to foods as they are being prepared in order to tenderize, add flavor, or to create a sour or somewhat acidic flavor. Marinating meat often involves the use of lemon juice or wine in order to weaken the connective tissues running throughout the meat, thus tenderizing the food item.