You're homebrewing, right? Just put a beaker of your Finished B100 in the freezer until it is solid, then let it thaw. When thawed, it should be crystal clear with no white residue settling to the bottom. If you do get the white residue this is high freezing point esters that have frozen and settled. This white goo will also form in the bottom of whatever your carrying B100 in, includng your fuel tank, and it will plug your filter real fast if it gets sucked into your fuel line. If the white stuff's in your containers, just pour the clear fuel from the top into your tank (as long as jostling around in your veh hasn't kept it from separating). But don't get the white stuff in your fuel tank! Save the white stuff and heat it when you get home, then mix it with your other B100 for use at home where it doesn't freeze.
If you do get the dreaded white stuff in the bottom of your beaker when freeze testing your fuel, do a search for "Glycerine pre treatment" to learn how to pretreat your wvo with glycerine byproduct. Pre treated WVO will produce fuel that is less likely to give you the dreaded white stuff, and will lower the gelling pont as well. I travelled through Wyoming in winter on B100 made this way once. Temps as low as 12F (at lest that's what the truck stop thermometer said) with no problem.
