Lemon juice will make milk curdle, but so does hydrochloric acid (stomach acid). So, milk always circles in your stomach and if this doesn’t give you GI distress, drinking milk before, during, or after drinking lemon juice won’t cause you a problem. You can add lemon juice to milk and watch it curdle. This is kind of fun. read more
Dr. Clay responded: Yes. The acidity of lemon will curdle milk; a phenomenon occurring within the stomach anyway. read more
Lemon juice and milk in combination won't harm your stomach or digestive tract, and, as pointed out, there are lemon-flavored creams and such which contain milk products. Plus, if you have a recipe which calls for sour milk (some cakes do) a little lemon juice will do that without actually causing the milk to "spoil". read more