Recipes and Cooking How to Cook Cooking Basics Why White Sauce Separates Wondering what causes a white sauce to separate and if there is a way to correct it? We've made a lot of white sauces and here's what we've learned. By Sheena Chihak, RD Sheena Chihak, RD Instagram Sheena Chihak is a registered dietitian, former food editor and current edit lead for BHG with over 15 years of writing and editing experience for both print and digital. Learn about BHG's Editorial Process Published on July 21, 2016 Share Tweet Pin Email A white sauce will separate if there is not enough added thickener (usually flour or cornstarch) or if it is not heated long enough for the flour to thicken the sauce (it should be cooked and stirred until bubbly, then 1 to 2 minutes more). If a white sauce is separated, try cooking it until bubbly. If it is still not a smooth, thickened sauce, stir together a little more flour or cornstarch with cold water, then add to sauce and cook and stir until bubbly. Continue the process until desired thickness. If you get lumps in a white sauce, remove immediately and whisk. If this does not help, strain out the lumps before serving. White Sauce Recipes Fettuccine Alfredo Pasta with White Clam Sauce Was this page helpful? Thanks for your feedback! Tell us why! Other Submit