The nature of potato salad is such that poorly cooked potatoes will ruin the entire dish. As the star of the bowl, you're gonna want to ensure that they're tender yet firm—but not crunchy. Starting the potatoes in cold water lets them cook more evenly, so you don't have little raw surprises in your salad. Once they're boiling, cook until they're just tender when pierced with a fork. Depending on the size of the potato pieces, this can take between 8 and 12 minutes. If for some reason, you drain them and find that they're undercooked, they can be saved. Dump them into a bowl lined with a paper towel, cover with another paper towel, and pop them into the microwave for 30 to 40 seconds at a time. If you're making lots of potatoes, don't try microwaving them all at once—do a portion at a time.