As of now, we're only getting whole milk from the new producer (it's the only thing their farm produces). I do know they use a low-temperature pasteurization method, but i'm not sure exactly what temp they use.
Perhaps it has to do with the non-homogenized nature of the milk?
In iced drinks, it tastes fantastic. If only we can figure out how to steam it correctly, we may stick with it.
It's non-homogenized? That's your problem. Homogenization breaks the fat up considerably. The fat and proteins create the foam. Without the fat as a buffer, there's no doubt that the steam will scald the milk it comes into direct contact with, even if the average temperature hasn't reached 140F yet.
I'm no chemistry expert, but based on my experience, this is the logic that I came up with.
Does it taste better than your previous milk? Just wondering...
(Skim milk is not homogenized, as the milk is allowed to separate and the cream "skimmed" off the top to produce fat-free milk).
I can't help but think it has more to do with the pasteurization, as the milk is processed at nearly the same temperature to which most baristas steam it. HTST and UHT methods, on the other hand, process milk at temperatures higher (or MUCH higher in the case of UHT) than we care to see in a cappuccino.