Just a footnote to a discussion about late lactation/late winter feed cow milk:
I have recently been having trouble getting a really nice firm curd with a variety of cheeses. I tried changing starter and rennet with no luck.
Finally came across the suggestion in "American Farmstead Cheese" to increase the free calcium for a better set. Thanks to the info here, I mixed up a 30% solution yesterday, and added 1/2t to a 3 gallon batch of tomme. I had a gorgeous floc and perfect curds. The whey was clear, not milky like it has been lately.
Something good to know.