Place the fat in a skillet or pot and add water so it reaches about halfway up the sides of the fat.

Set the burner to its lowest setting and let the liquid simmer for 60-90 minutes.

When it starts to look as though the simmer is dying down, watch the fat carefully. It should be a warm golden color, with smaller bubbles. As the water evaporates, those bubbles will come closer to a boil and the remaining liquid will turn a darker golden. Eventually, the boiling bubbles will suddenly become much smaller, just back to a bare simmer, which means all the water is gone.

Remove from the heat immediately and pour it through a fine mesh strainer. Let cool to room temperature, transfer to a glass jar and place in the refrigerator for 1 month or the freezer for 6 months.