When the price of middle distillate fuels used in normal commercial operations increases, the use of alternate fuels as blending stocks becomes more attractive. In military applications, middle distillate fuels must pass more stringent requirements, and storage stability becomes a critical factor. Military fuels often remain unused in storage for months and sometimes for years, and can become unstable. The formation of particulate matter can plug fuel injector nozzels and fuel filters, which can degrade engine performance and cause engine failure. Soybean derived fuel, when added to middle distillate fuels enhances storage stability significantly. Blends in the 10-20% concentration range yield fuels that are stable for at least a year. Soybean derived fuel used as blending stock makes a biodiesel fuel that meets or exceeds ASTM requirements when mixed with stable and some unstable middle distillate fuels.