Previous studies have highlighted Brettanomyces claussenii OYL-201 as a versatile yeast that can produce ethanol or acetic acid from lactose or selectively metabolize glucose while leaving behind galactose, depending on a variety of operational conditions. This flexibility enables the production of multiple galactose-rich bioproducts from liquid dairy residues. The purpose of this study is two-fold: (i) optimize this partial anaerobic fermentation of milk permeate (MP) by B. claussenii to maximize the yields of galactose and ethanol and minimize leftover glucose, and (ii) combine this optimized process with distillation and freeze-drying to characterize multiple products resulting from this approach. To achieve this, response surface methodology via central composite design was used to create the optimization models. Three fermentation parameters were chosen as input factors: temperature (25°C - 35°C), inoculation level (7.0 - 8.5 log cfu/mL), and time (4 – 40 days), with three metabolites as responses: galactose, glucose, and ethanol. The optimal combination of parameters found was temperature, 28°C; inoculation level, 7.6 log cfu/mL; and time, 33 days. These were used to run an 18-L fermentation followed by distillation and freeze-drying. As a result, four product streams were obtained and characterized for relevant physicochemical and nutritional attributes. Our results show that the partial fermentation of MP by B. claussenii can be used as the first step to develop lactose-free, low-in-glucose, galactose-rich bioproducts, which improve the value of this residue and broaden its applications in the food supply chain.