Last night, I made homemade ricotta for a dinner party tonight using organic milk (exp 3-18) and cream (exp 3-11) I bought the same day at Whole Foods, with lemon juice and salt. It turned out great - after draining it, it smelled and tasted wonderful. I put it in a clean plastic container with a tight-fitting lid and put it in the refrigerator overnight. I opened the container this morning and it released a strong off-putting smell - gasy and sort of sulphuric. I won't be serving it. Has this ever happened to anyone else? The milk and cream still smell fine in their containers. The only thing I can think is that the cream is a type I've never used before - grass-fed, unhomogenized. I'm going to replace the dairy and make a new batch today.