The aim of the study was to obtain hard cheese similar to the rennet hard cheese starting from the fresh white cheese (low and full-fat). This was accomplished with adding a powdered whey protein isolate to the fresh white cheese and heating. Fresh white cheese was produced from full or skim milk and ground with the whey protein isolate powder. The obtained mixture was heated at different temperatures. The increased heating temperature resulted in a more compact product characterized by higher hardness and elasticity compared with the full-fat product. The product approved by the organoleptic analysis panel was obtained by heating the mixed fat white cheese and the powdered whey protein isolate at 80°C for 30 min. The most significant achievement was to obtain in ca. one hour a product similar to that produced in ca. one year that is the hard rennet cheese. It contained ca. 39% wt/wt of protein and can be an interesting offer for dairy industry.