Biodiesel is sort of like buying cheese. Some of it is fantastic, and some isn't so hot.
Enter the pHLip, a testing system from CytoCulture, which specializes in oil spill technology. Place a few drops of the biodiesel you are thinking of buying into the vial, shake it up, and then let it stand. If the fluid on the bottom stays cherry red, you have yourself good biodiesel, says Randall von Wedel, principal researcher at the company.
If the color changes and the barrier between the different liquids in the jar gets gummy and opaque, the biodiesel contains contaminants. Biodiesel, by the way, is safe it drink, von Wedel told me. I tried it. It tastes like old salad dressing.
You can buy the kits on the company's site.
Testing is probably going to be a feature of the market for a while because standards haven't evolved, said von Wedel, who drives a fancy biodiesel Mercedes. He sometimes gets biodiesel at Fish, a Sausalito restaurant that has a growing biodiesel business. They make the fuel from the deep fat fryer drippings in the restaurant.
Both the fish and fuel are rated highly.