The use of cutting fluids during machining processes remains one of the main challenges toward greener manufacturing, mainly when applied by flooding. The use of vegetable-based cutting fluids stands out as one of the alternatives toward more sustainability by making the process eco-friendlier without much impact on the economic aspects of the chain. In this paper, the performance of two vegetable-based cutting fluids applied by flooding was compared to one mineral-based during the turning process of the AISI 1050 steel. They were also tested after aging for microbiological contamination to assess the fluids’ sustainability further. The machinability of the cutting fluids was evaluated by considering the tool life and wear mechanisms, workpiece surface roughness, and cutting temperatures. After microbial contamination, all the fluids increased kinematic viscosity and specific weight, except for the emulsion of vegetable-based fluid, where its kinematic viscosity decreased. The vegetable-synthetic fluid obtained the best machining results in cutting temperature and roughness (Ra) and also had the best behavior for microbial growth. However, considering the tool life, the best result was obtained with the emulsion of the vegetable-based fluid.