Marinades are used as a way of tenderising dry or tough meat and to add flavour. Foods cooked on a barbecue benefit from marinating in oil and acid of some sort. The oil adds moisture while the acid tenderises. Marinades comprise some sort of moisture, such as oil, vinegar or lemon juice, and any of a number of aromatics. Aromatic herbs should be of the stronger varieties, such as rosemary, thyme, bay or oregano. Milder herbs such as tarragon, chervil or parsley are better added at the end of cooking. There are also dry marinades and pastes which are rubbed into the surface of the foods. Using too much salt will mean that the moisture is drawn from the meat, rather defeating the object.