This recipe comes from Cook's Illustrated "The Best Make-Ahead Recipe" Book. This was absolutely the best mashed potatoes I have ever made and the family all agreed. Rich and silky, easy, easy! Anyone who has used a Cook's Illustrated recipe knows that they go into great detail on how they come up with a recipe. There is no room here for their explanation of their cooking methods, but just trust me, this is a must have recipe. Purchasing this cookbook has been so worth it, everything I have tried so far is great!