Johanne (Hanne) Ane Margrethe Nielsen (1829–1903) is the Danish inventor of Havarti cheese. In the 1800s, Nielsen traveled around Europe to learn about cheesemaking. Nielsen's farm was in Havarthigaard, north of Copenhagen, and in 1852, after returning from her travels, developed the technique to create Havarti, a semi-firm cheese dotted with small holes.
Havarti was, however, not introduced in Denmark until around 1920.
The original Havarti cheese is different from flødehavarti ("cream Havarti"), which is made from high-pasteurized milk, so that the whey proteins that would otherwise be eliminated during production remain in the curd. This raises yields, but alters the taste and texture. Cream Havarti usually ripens very little, since the remaining whey proteins cause problems (off-taste, odd appearance) during prolonged ripening.