Plant-based sources are being assessed as alternatives to animal-based foods as a strategy to reduce environmental impacts. This study aimed to calculate the environmental footprint of dry bean flour made from Phaseolus vulgaris cultivated in northwest Argentina. Since grain pre-treatment influences the flour’s nutritional properties, three different processing methods were evaluated: raw (R-BF), soaked (S-BF), and soaked and cooked (SC-BF). A comparative Life Cycle Assessment was conducted, evaluating multiple impact categories using the ReCiPe method. The functional unit was 1 kg of flour, and the primary stages assessed were seed and grain production, transportation, processing, and flour production. Inventory data were based on Argentina’s 2023 harvest. All impact categories were higher for S-BF and SC-BF due to several factors. First, flour yield decreased from 0.97 for R-BF to 0.80 and 0.74 for S-BF and SC-BF. Additionally, soaking and drying before milling in S-BF increased electricity and water consumption. SC-BF required further inputs of water and natural gas for cooking. As a result, the most significant differences were observed in global warming, fossil resource scarcity, and water consumption, with values 4, 5, and 8 times higher than R-BF, respectively. Regarding ecotoxicity, pesticide use during seed and grain production had a substantial burden, contributing 82% to freshwater and 64% to terrestrial ecotoxicity. Transport and agricultural machinery accounted for up to 90% of R-BF’s acidification impact; this share decreased by 20% in S-BF and SC-BF due to higher electricity use. Transport remained a major contributor in several categories because of distribution distances. Water consumption for soaking and cooking represented 6% and 15% of total impact for S-BF and SC-BF. This analysis highlights how processing methods affect the environmental footprint of flour.