Many of our recipes start by cooking chicken, pork, and beef in water. My mom is obsessed with using a round skimmer to remove all the foam made from fat and scum that rises to the top of those bubbling meat broths. Technically speaking, that foam is harmless and will eventually get integrated back into the broth after simmering for a while, though it will make the broth cloudy and a bit gray. This technique is mostly for aesthetic reasons to have a crystal-clear broth, but it also produces a cleaner-tasting stock.