Heptyl oleate synthesis is a good test to compare crude lipases. Being a reaction selective for lipases, esterases and proteases are not active in this esterification. The heptyl oleate synthesis has been carried out with crude lipases and other hydrolases (such as proteases and esterases) from different suppliers and origins, in order to explore the methodology scope. While the initial rate of esterification seems to be mainly dependent on the concentration of lipases in the sample tested, the final synthetic yield depends on the total amount of water in the reactor. The standard protocol to evaluate crude lipases is described.