In the food industry, there is currently a great deal of interest in the development of plant-based alternatives to dairy products. However, little is known about the ways in which differences in formulation and/or processing affect the potential environmental benefits of such products. In this study, we investigated the environmental performance of four new fermented products created using different mixtures of plant- (pea) and animal- (cow milk) derived protein sources and prepared using a cheese-technology process (Camembert production). Life cycle assessments (LCAs) were performed that included all steps from the agricultural production of ingredients to the generation of the final ready-to-eat product. The goals were to identify the hotspots of this production system and to compare the different products to each other as well as to other common fermented or legume-based products (Camembert, tofu, hummus). The LCA results revealed that the two main hotspots for the mixed products were milk production (when used) and the ripening stage. All four products were similar with respect to the environmental impacts related to processing. Instead, with regard to the impacts of agricultural production, the products made with a higher proportion of pea protein were superior, providing clear evidence of the potential environmental benefit of pea-milk fermented foods. Overall, though, the mixed products did not present any environmental benefit compared to Camembert, hummus, and tofu due to the complex and energy-intensive nature of the manufacturing process. It is therefore critical that these processing steps be simplified and optimized in order to realize the environmental potential of such pea-based products.