@Sturgis,
It was "animal milk", from cows I think, and the type of cheese was ... well, they just found fatty acid residues, so it would be difficult to compare it with nowadays known types. But one of the authors guessed, it was "like a farmer’s cheese or perhaps like a feta". (
Source)
The ceramics are called "rhyta" (singular: rhyton), most probably designed/used just for cheese-making. (Same sources as previously)