Fat should always be removed before stock is used. The easiest method to
accomplish this is to cool the strained stock quickly by allowing it to sit in a
bowl of ice. Once cooled, pour the stock into a bowl and allow it to chill
covered and undisturbed in the refrigerator for at least four hours. The fat
will rise to the top. If the fat content is minimal, it will appear in small
globules. Larger fat content will appear in a hardened layer on top of the bowl.
Once hardened, the layer of fat can be easily scooped out with a spoon.
If there isn’t enough time to allow the stock to cool, skim off as much fat
as possible with a slotted spoon. An easy trick for removing fat is to put
several ice cubes into cool stock and stir them around for a few seconds. The
fat will cling to the ice, and then easily removed. Another method for removing
fat is to draw a paper towel sheet across the top to soak up surface fat. This
step will most likely have to be repeated several times in order to remove all
of the fat.
Stocks can be reduced to concentrated form by boiling it rapidly on the stove
top after all the fat is removed.