Why do you need raw milk to make butter?
You don't need raw milk (or more precisely, raw cream). I've made butter from cream many times, but never from unpasteurized cream -- I prefer locally sourced organic cream for reasons, but the actual butter-making process is exactly the same with a pint of store-bought.

If you are starting from milk rather than from cream, you will need to get non-homogenized (or unhomogenized) milk. Homogenization and pasteurization are separate processes (even though both are typically performed on milk): pasteurization uses heat to kill bacteria and other pathogens, while homogenization breaks up milk fat particles so they stay mixed into the milk instead of rising to the top.

If you want to buy pasteurized, non-homogenized milk to skim your own cream, it may be labeled as cream-top or creamline milk. Raw milk is both unpasteurized and non-homogenized, but I personally like the increased safety that comes with pasteurization.



Personal anecdote: I once bought cream-top milk to try to skim it for butter, and the amount of cream a half-gallon produced was about a tablespoon. For me, that wasn't nearly enough to justify the extra work -- my family doesn't drink nearly enough milk in a week to salvage the necessary cream for butter-making. I personally recommend skipping straight to cream :)