Key tests include viscosity, density, flash point, acid number, ester content, and water/sediment presence. These tests confirm compliance with ASTM D6751 or EN 14214 standards. GlobeCore also offers compact biodiesel testing kits for field verification. Advanced labs may use gas chromatography (GC) to confirm ester composition. Proper testing ensures safe engine use and helps monitor feedstock or process variability. High-quality biodiesel will have low moisture, high ester purity, and good oxidative stability.