We have canned cheese, butter and cream cheese. I just opened a cream cheese (after reading your question) we canned a year ago, tastes quite good I don't notice any difference between fresh and year old canned. The cheddar cheese I opened after a year, and it was fine and cooked with it. For cheese, it looks safe to can, if cheese can sit on a wooden shelf and age 10 years, it can go into a jar and be sealed. No fear of botulism because most cheese is dry enough the bacteria can't grow, salty enough and the PH is just low enough that it doesn't promote growth. Butter is safe, once clarified it is mostly oil, botulism needs water to grow, not oil. The only problem I noted with butter is, once clarified and canned ,and once opened it will go rancid sooner than fresh butter. So follow the directions, sterilize your jars and heat the cheese and all should be fine. The only cheese you have to worry about is wet cheese like cottage cheese or ricotta. I seem to recall an article in Countryside magazine last spring or early summer about canning cheese and butter, if you get that magazine.
