Schmaltz is fat from a chicken. You don’t see it around much anymore, but once it was a very common thing in Germany and Austria, and among the peoples who emigrated from there, notably the Ashkenazi Jews. Though the word “schmaltz” can technically refer to beef, pork and even goose fat, it’s come to mean “chicken fat” among people who use it in the States. The cost common use for schmaltz was as a spread, which is to say it was used like butter on toast. However it makes a very nice general-purpose cooking fat as well, and is useful in baking as a tenderizer for doughs (I’ve used it in knish dough) and some crusts.
That’s where the utility of schmaltz mostly ends in the pastry kitchen because schmaltz isn’t terribly firm. Which means — yes you guessed right — that it’s lower in saturated fat than either pork or beef fat. And that makes it healthier in some peoples’ eyes. Schmaltz can be easily made at home by gently heating chopped pieces of chicken skin in a pan with a very small amount of water (some people add a few chopped raw onions to the pan to add flavor). After about an hour very, very low heat cooking, the fat melts and can be strained through cheese cloth or even paper towels into a refined fat. Once cooled you can use it for just about anything. In fact there was a soul food restaurant here in Louisville that used schmaltz instead of mayonnaise to make chicken salad. When that place closed I was depressed for a month.