B100 found in the United States cannot be effectively managed with current cold flow additives like some petrodiesel or European rapeseed oil based biodiesel. The U.S. oils and fats contain too high a level of saturated compounds for most additives to be effective. Cold flow additive effectiveness can also change dramatically depending on the exact type of biodiesel and the processing it has undergone; much like the situation found with diesel fuel. Cold flow additives have been used much more successfully with biodiesel blends.
There are efforts underway to design new additives specific for U.S.-based b100, and there are processes which serve to winterize biodiesel by removing some of the saturated compounds. At present the cost of these approaches makes them undesirable. As time goes on, and biodiesel volumes increase, expect to see more progress in this area.