Also referred to as Stearin in some circles, this palm derived product is wonderful in creams and lotions as an emollient and thickener. It is used in candles to make the wax harder and give a slower burn to give you a longer burning candle as well as greater opacity. It may also give a creamier finish to your candles.
Stearic Acid added to soaps will make them harder. This product is generally used at between 1% and 3%.