Frequent navigation in ice-infested waters causes brash ice formation and accelerated ice growth. Large ice accumulation in ports and vessel tracks can hamper maritime activities. Therefore, the forecast of brash ice occurrence requires accurate prediction models based on frequent and comprehensive observations and measurements. However, field and large-scale laboratory testing for thorough brash ice investigation require significant resources. The current work outlines experiments on the formation of a freshwater brash ice channel in a tank. Thetank was exposed to outside weather conditions during winter meteorological conditions in Luleå, Sweden, where the air temperature went down to -25ᴼC. The channel’s geometry and ice thickness evaluation were systematically measured. The results gave insights into the laboratory-scale brash ice formation. Moreover, the influence of snowfall on brash ice solidification in the early winter is observed. The observed brash ice formation and especially thickness is reported and compared with predicted values. The work concludes by discussing the advantages, challenges, and limitations of this laboratory-scale brash ice formation method derived from the current tests.