I remember two cans on Grandma’s stove. One was the ‘for company’ grease the other for general use. She would pour the clear, or top grease off in one jar and the remainder in the other jar. So one was pure white the other had bits in it.
The company lard was used for biscuits and baking the other for general grease. I never had two cans, all fat went into the one and the bits just settled to the bottom. Never remember it going rancid but do not recall how long the can was used for, years to my recollection. Just take a spoonful out whenever frying anything in a pan.