Cooking Q&A's, Videos, Tips, and Customized Recipes
As far as sauce “breaking”, there is a simple principle at play. Sauces (and dressings) that stand a high risk of breaking are those classified as emulsions. Emulsions are defined as combinations of liquids that do not normally mix together well (namely oil and water). Alfredo sauce is an emulsion of butter and cream in which small amounts of cream are added to melted butter while whisking rapidly. The three elements to an emulsified sauce to focus on are: the amount of butter / temperature / and speed of mixing.
But I can break it down for you even further. If you make a sauce over high heat, you can add the butter all at once but you need to whip it very vigorously. If you lower your heat, however, you will buy more time to mix it a bit less aggressively. Either way, once you mix it, remove the emulsified sauce from the heat, or it will break. In the case of an Alfredo Sauce, add small amounts of cream at a time and use a low heat.
There is a catch, though. You don’t want to let the sauce get cold, or else it may congeal. This is especially true for Alfredo Sauce. The trick is to keep it warm, even during serving and eating. Too hot and it breaks. Too cool and it congeals.
Angelica has indicated that she is using chafers, which will quite likely be kept hot by blue-flamed cooking fuel cannisters underneath. This may be too much heat. To control the heat these hot little guys give off, try reducing the number of them per chafer (there are usually two; try using only one, although you may want to assign someone to rotate it to keep the pasta from becoming unevenly heated). Or, elevate the chafers slightly to increase the distance between the flame and the bottom of the chafer pan. And remember, more water in the base of the chafer can actually help to control the intensity of the flame cannister.
Use heavy cream for your Alfredo, not milk, and especially not low-fat milk. Low fat milk curdles easily even over mild heat. Also, try simmering only 3/4 of the cream in the recipe, and then stir in the remaining cream after removing from the heat. You’ll get a better flavor and texture that way.

Another key trick is to serve the Fettucini Alfredo in warm bowls. Heavy ceramic bowls are ideal, as they hold heat longer. Just set up the bowls in a warmer or an oven at very low temperature (you should be able to hold to bowls with your bare hands). That way the sauce will not congeal and become clumpy.
Another suggestion, use fresh pasta rather than dried. It grabs the sauce better. Also, regardless of the pasta you use, reserve a little of the pasta water to add to your sauce at the last minute. The sauce consistency should be just a little thinner than what you envision, because it will thicken slightly as it is exposed to the room-temperature air, just as the pasta should be al dente, as it will finish cooking in the chafer.
Have fun cooking with your self-catered wedding, Angelica! We’d like to recommend that you sign-up for our Menu Plannning Service and select one of our expert chefs as your personal culinary consultant. Our service includes the creation of a complete and customized menu with you, all recipes to scale, a shopping list, cooking schedule, wine pairing suggestions, and of course live coaching every step of the way. Congrats and buon appetito!