If you make the potato salad ahead of time or are munching on leftovers, you will want to know when it’s terrible so you don't risk becoming ill. First, it’s essential to know that no potato salad should ever sit out longer than 2 hours because bacteria will grow rather quickly. Once the loaded baked potato salad starts going rancid, you will notice it may become extra water, have an unpleasant odor, or have mold. If you notice any of these issues, toss them!