Triticale (× Triticosecale Wittmack), developed by crossing rye and wheat, is increasingly applied in food production. The aim of this paper was to study the grinding process of eight new triticale grain (TG) varieties harvested in 2020 and 2021. TG was tempered to 12% of moisture and a knife mill was used for the size reduction. The following parameters characterizing the grinding process of TG were determined: specific grinding energy, Sokołowski grinding index, particle size distribution and average particle size. Additionally, the basic chemical composition, total phenolic content and antiradical activity of TG were determined. The protein content of TG was strongly influenced both by the variety and harvesting year, while other components were mostly affected by the genetic factor. The strongest influence on the grinding indices has a variety of TG. Specific grinding energy varied in the range of 14.0 kJ kg−1–17.8 kJ kg−1 and was positively correlated with the size of ground particles. Especially, the grain of Belcanto required lower grinding energy requirements and showed the strongest antioxidant capacity compared with other varieties of TG.