664458 Tue Nov 03 13:52:10 -0800 2009 6 31 Home Cooking 0 5153008 Several times I've made a basic marinara sauce and shortly before it's done I've added a little whole cream without a problem. Last I night I made the same thing but added half and half since I had some on hand. As soon as I began to stir it in, it started to seperate and instead of a nice creamy sauce, it had little grainy clumps in it. It was awful! What happened? Was it too hot? Or can't I use half and half in a sauce like that? Tue Nov 03 13:52:10 -0800 2009 254475 Ritcheyd 1 5153014 My guess is the whole cream has enough fat to blend smoothly while the milk content of the half & half was high enough for it to curdle on contact with the acid in the sauce. Tue Nov 03 13:54:13 -0800 2009 5153008 14386 BobB 1 5153018 You should have tempered the H & H first......it was probably too cold. http://www.ehow.com/how_5352414_temper-cream-making-sauce.html Tue Nov 03 13:55:04 -0800 2009 5153008 123497 fourunder 1 5153055 I suspect the H&H is on the brink of turning sour, if not already there. Tue Nov 03 14:03:12 -0800 2009 5153008 159317 greygarious 1 5153056 Too big of a temperature difference can cause it to separate or seize up. Next time, add a little bit of your sauce into the half and half, and then add that into the pot of sauce. Tue Nov 03 14:03:13 -0800 2009 5153008 1107401 Chefthekitty 1 5153207 Heavy cream has a higher fat content (at least 36% by law, less for "ultra-pasteurized" and whipping cream) than H & H (10-18%) and doesn't separate when heated, even in an acid. See the link below for an explanation of emulsification, casein proteins, etc. The lower the butterfat content, the more likely the product is to curdle, which is what happened to your sauce. Heat also affects H & H and it has to warmed before being added to a hot liquid. When it "breaks" in coffee, it's due to the acidity and also indicates that the H & H is not very fresh. Stick with heavy cream and you'll be fine. Here's another thread on this subject: http://chowhound.chow.com/topics/375635 Tue Nov 03 14:45:35 -0800 2009 5153008 1095104 bushwickgirl 2 5153280 "Stick with heavy cream and you'll be fine." ~~~~~~ agreed. i don't "get" half and half anyway. than again, i'm not food-fat-phobic. Tue Nov 03 15:10:53 -0800 2009 5153207 30273 hotoynoodle