Q. Is there something called fat-free butter? If there is, where can I find unsalted fat-free butter?
There is no such thing as fat-free butter, and consequently, no such thing as unsalted fat-free butter. By law in this country, butter must be
at least 80% fat. The rest is water, milk solids, and often salt. Fat-free butter, then, would be primarily water with a small volume of milk solids definitely not something you would want to spread on your toast.
There is such a thing as "light" or reduced-calorie butter, which substitutes more water, skim milk, and gelatin for some of the fat. The calorie count is cut in half, and you can generally find salted and unsalted
versions in a grocery store.