In this study, the partitioning of minerals in ultrafiltration (UF) streams of skim milk using cross-flow (CF-UF) and dead-end (DE-UF) was investigated using 50 kDa membrane at different temperatures (5, 10, 25, 35, 55°C). CF-UF showed higher protein retention (6.02–10.9%) compared with DE-UF (3.44–4.70%), along with more retention of calcium, with values ranging from 29.8 to 41.5 and 57.8 to 112 mM for DE-UF and CF-UF, respectively. Ionic calcium in permeates varied less for CF-UF (2.48–1.18 mM) than for DE-UF (3.11–0.98 mM). The insights provided in this study can be exploited to tailor adjustments of minerals in milk streams using UF.