The course of hardness changes in KC was different from that of ES (Fig. 2B). Hardness of KC was rising with the increasing maturity degree of cheese until the 4th week (P < 0.05; Fig. 2B). Subsequently, a relatively rapid decrease in hardness occurred in KC made of cheeses with 6–10 weeks of maturity (P < 0.05; Fig. 2B). In the most of KC made of cheese with 12–16 weeks of maturity, no significant changes in hardness were detected (P ≥ 0.05; Fig. 2B). Hardness of KC measured on the day of production was always lower than the values of this parameter on the 7th and 30th day (P < 0.05) regardless of the maturity degree of cheese. In the most of KC, hardness on the 30th day was slightly higher than that of the 7th day (P ≥ 0.05). Hardness of KC was always higher than those of the corresponding ES (made of cheese of the same maturity measured on the same day after the production; P < 0.05; Fig. 2).