Maybe try milk straight from the farm. We just started a dairy share and purchased milk. 1 gallon of milk has 3-4 inches of yellow-orange cream that settles on top. This milk was from Holstein cows. Most U.S. milk is ultra pasteurized and I suspect something is added to lengthen shelf life. Cream today is not real cream, it takes forever to whip. It never took that long when I was young. My mother could shake or whip with a manual whip and make cream or butter.