Thank you all, I got it!!!
4.5 l of Haloumi whey, 4.5 l of MOZZARELLA whey, 1.9 l raw milk added at 72 C + 1 cup of vinegar at 90 C. It looked that I shouldn't have to add the vinegar but it increased the yield. The outcome was 620 gr of fantastic fatty and sweetie Ricotta.