Using the wrong potatoes
Buying the wrong potatoes is one of the most common mistakes people make when making potato salad. If you are unfamiliar with the various types of potatoes, you may believe that they are all the same. However, when it comes to creating the perfect texture for potato salad, this is not the case. Rather, you should pay close attention to the potatoes you choose at the store.
A waxy potato, such as fingerling, red, or new potatoes, is your best bet for potato salad. These work well because they retain their shape, preventing a gloopy texture. It all depends on what you want from your potato salad. Some people prefer softer, starchier potatoes, such as russets. If you want the potato to fall apart a little in your salad, this is a great option. Starchy potatoes will have a more mashed potato-like texture, whereas waxy potatoes will stay more intact. Consider what you want from your potato salad and choose your potato variety accordingly. Because these potatoes cook at different rates, you probably won't want to combine them in your potato salad.