Significant volumes of skim milk are concentrated in the Dairy Industry, primarily as an intermediate step in the production of milk powder. When concentration is conducted by thermal evaporation, detrimental changes to product quality occur. Additionally, mesophilic and thermophilic spores can develop and form biofilms within milk evaporators. These spores are extremely difficult to remove and ultimately affect the quality and shelf life of products made from the concentrated milk. In this work, the process of concentrating milk using forward osmosis (FO) was evaluated for its ability to concentrate skim milk at refrigerated to sub ambient temperatures and maintain product quality unchanged. Pasteurized skim milk (Cornell Dairy, Ithaca, NY) was concentrated at 4°C and 15°C using a pilot-scale FO unit (Ederna, France), equipped with a polymeric membrane. Batches of 8L of skim milk were concentrated in triplicate, and the physico-chemical properties of the concentrates were evaluated. The water flux for the FO process decreased exponentially with time, while sample concentration increased exponentially. At 4°C, flux decreased from 3.02 ± 1.32 L/(m²h) at 5min (initial sample °Brix: 9.83 ± 0.15°) to 0.96 ± 0.21 L/(m²h) after 7h (sample °Brix: 28.50 ± 0.78°). The flux was higher for the 15°C runs, ranging from 3.13 ± 0.57 L/(m²h) at 5min (initial sample °Brix: 9.83 ± 0.15°) to 0.87 ± 0.18 L/(m²h) at 7h (sample °Brix: 33.17 ± 2.39°). Because of the lower viscosity at 15°C, a higher concentration factor was achieved at this temperature (4.17 ± 0.65) as compared with 4°C (3.37 ± 0.43). FO concentrates were diluted to their original total solids (TS) content with deionized (DI) water and subjected to color measurements, in triplicate, using a CR-400 chromameter (Konica Minolta, Japan). Luminosity (L*) values of concentrated and re-diluted FO concentrates were not significantly different (P > 0.05) compared with the original skim milk. These results demonstrate that FO can achieve a high concentration factor for skim milk, with no impact on the product color or its chemical components. The process requires further optimization to maximize concentration rate, but the data obtained so far suggests that FO can be a very attractive alternative to thermal concentration of milk.