The most common signs of too much acid in a dish are an overly sour or tart taste, a metallic or chemical aftertaste, and a curdled or separated sauce. Adjusting the flavor balance is crucial to rescue the dish.
When you add too much acid, such as lemon juice, vinegar, or wine, to a dish, several telltale signs will indicate the imbalance. The most obvious is the taste. The dish will have an overwhelmingly sour or tart flavor that dominates all other ingredients. This sourness can be unpleasant and make the dish difficult to enjoy.
Another sign is a metallic or chemical aftertaste. This can occur when the acid reacts with certain ingredients, particularly in dishes containing dairy or certain vegetables. The acid can also denature proteins, leading to a curdled or separated sauce, especially in creamy soups or sauces. The texture will become grainy or lumpy, rather than smooth and velvety.
Finally, pay attention to the overall balance of the dish. If the acidity overpowers the other flavors, masking the sweetness, saltiness, and umami, it's a clear indication that you've added too much acid.
If you've added too much acid, try balancing it with a touch of sweetness (a pinch of sugar or honey), richness (a pat of butter or a splash of cream), or even a pinch of salt. These additions can help to neutralize the acidity and restore the flavor balance of the dish.