Cheese added to a soup can clump if the chef is not careful. If you're melting cheese straight or mostly so, like cheese toast or a decorative sprinkle on top of something, simply sprinkling or spreading water on top will give a bit of encouragement for the cheese to melt instead of dry out. Make sure to shred your own, instead of using pre-shredded product -- that stuff has additives to prevent clumping, which prevent good melting (plus the cheese itself may not be the best). It may take longer, but it will stop the clumping. :( It's the standard Kraft Grated Parmesaen in the can. My grated cheese is all clumped up. CHEESE NEEDS LIQUID. There are a few things you can do to help make this method a little easier. It's great the first time you open it; it's all nice and powdery-fine and goes on easily. Once all the cheese is in and melted, you can then incorporate your pasta. Yeah, you'd basically be making something like a Mornay or an Alfredo sauce. First, spray the blades of the processor with a little cooking spray to help keep the cheese from clumping on the blades. Let your cheese sit out until it comes to roughly room temperature before you try to melt it. – Jacob G Apr 30 '12 at 17:40 Let the cheese come to room temperature. Melt the butter, incorporate the milk/cream and, once hot, sprinkle the cheese in smaller than 1/4 cup increments stirring constantly. American made parmesan doesn't have the same characteristics as the genuine imported stuff so that might have something to do with it. This allows it to mix and melt in easier, while giving you more control over how much you add. If you melt cheese cold, it may cause it to melt slowly or unevenly. Cheese that is grated in larger shreds has a larger surface area and so is more likely to clump. Sprinkling cheese onto directly onto pasta will result in a lumpy mess. Second, make sure the cheese is cold. If you're melting a drier, sharper cheese, you can grate or shred it, and let it sit in water for a while to hydrate. But then you have to refrigerate it after it's been opened and that's when the problems start. Using a grater, as opposed to thinly shaving the brick of cheese, or cutting it into chunks, makes the parmesan perfect for a pasta topping or to use in recipes requiring freshly grated cheese. Cold cheese is less likely to be turned into cheese … Also this method of emulsifying the sauce is more difficult than just ignoring the butter and water and melting your cheese directly into heavy cream and with the quantity of butter specified in the recipe i'm not even sure it's a healthier alternative. Grr. Also add the cheese in small additions. Turn the box grated to the smaller side and use it. Grating your own cheese is not as quick and easy as using pre-grated cheese, but the flavor results are well-worth the extra preparation time. Do not leave cheese sitting out for more than two hours. Picture the parmesan in the shakers. If the cooking temperature is too high or the soup doesn't incorporate wine or another acidic ingredient, clumps may form. Most cheese will come to room temperature in about 20 to 30 minutes.