When I'm pulling fat from the top of a pot of animal broth that I'm making after butchering day, I occasionally ladle off 3/4 - 1 pint full of broth from the top, put it in a pint jar with a lid, turn it upside down in the fridge and leave it over night.
The fat, rising to the top, will be have become firm in the cold refrigerator and be on the bottom of the jar when I flip it over the next day. The broth, which has also firmed into a solid state due to the gelatin released from bones and feet, will come out of the jar in a single disc.
I put the disc of fat in one jar and the disc of gelled broth in another, label them and put them back in the fridge. The fat will be used when I'm frying and the flavorful broth will be added to soups, stews or used as the liquid for cooking grains and legumes.