Put the potatoes in a large pot and cover with cold water. Bring to a boil over medium-high heat and cook the potatoes until tender, about 15 minutes. Drain and let cool slightly. Carefully peel and chop the potatoes into 1/2-inch chunks.
In a large bowl, combine the mayonnaise, milk, bacon, ranch dressing mix and scallions and stir together. Add the potatoes to the bowl and toss with the dressing to coat. Let the potato salad cool completely. Cover and refrigerate for at least 4 hours and up to 24 hours before serving. Transfer to a platter and serve.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.