Yesterday, I decided to try a homemade mac and cheese recipe. Everything was ok until I added the cheese to the milk. The sauce became visually cloudy and the texture was gritty. I thought the possibly that the cheese didn't have enough heat after turning it off, but the problem still existed after popping it out of the oven. The recipe I followed is here: http://gonnawantseconds.blogspot.com/2011/01/almost-zovs-mac-and-cheese.html I've made an alfredo sauce before and had no problems like this. What should I do next time to create a smooth creamy sauce?