A grease collection system is provided that may be connected to an oven for the real-time removal of grease from the heating chamber while maintaining a closed system. In particular, one end of a grease removal conduit is placed in communication with a drain in the cooking chamber, and the other end of the conduit is placed in a portable reservoir for the disposal of grease having a predetermined fluid level to prevent ambient air from entering the heating chamber during the preparation of food product.