Adding vinegar too early in a dish can result in a harsh, acidic flavor and can prevent other ingredients from softening properly. It's best to add vinegar towards the end of cooking to preserve its brightness and balance the flavors.
Vinegar is a powerful ingredient primarily used to add acidity and brightness to a dish. Its flavor is derived from acetic acid. When vinegar is added too early in the cooking process, the heat can cause the acetic acid to become more concentrated and intense, leading to an overly sour or sharp taste. This can overpower the other flavors in the dish and create an unpleasant experience.
Furthermore, the acidity of vinegar can interfere with the softening of certain ingredients, particularly vegetables and beans. The acid can toughen the cell walls, preventing them from breaking down properly during cooking. This can result in a dish with uneven textures and longer cooking times.
Adding vinegar towards the end of cooking allows its flavor to meld with the other ingredients without becoming overly concentrated. It also preserves the vinegar's bright, fresh character, adding a final touch of acidity that balances the overall flavor profile of the dish. The heat will still mellow the vinegar slightly, but not to the point of losing its intended effect.
When adding vinegar, start with a small amount and taste as you go. You can always add more, but it's difficult to remove the sourness if you add too much at once. A little goes a long way!