That is a great question, and the answer is for Cholov Yisroel -
Mehadrin & JJ, both the whipped butter and the butter sticks are legal and contain just the milk cream (and salt if listed). Now - some packaging will list "natural flavors" - however, that's only because the label hasn't been updated in many years, but the way they make it currently is without any flavoring - and technically the words "natural flavors" need to be removed from the ingredient list. I have confirmed this with Mehadrin. If anyone wants to personally confirm it, feel free to call 718-456-9494 ext 342.