I was a CIP technician at an organic juice company once and had to clean and sterilise the pasteurizer every shift. There are a few centrifugal pumps, holding tanks and pipe connection manifolds in play. You basically run hot water a few minutes through it then run caustic(sodium hydroxide) for a few minutes as well then rinse. It's basically a small radiator that recirculates the liquid to reach a certain temperature(hot water pumped through a different circuit) at which point the thermostat kicks in and releases a solenoid valve that lets the liquid flow to the holding tanks in the post-pasteurization room(That I would wash clean along with the tanks with pressurised foam bleach. I miss the smell.). This isn't relevant to the post. I'm just drunk and reminiscing about one of the few jobs I actually enjoyed. More relevant to the post: I bought ultra-filtered milk recently and the taste was amazing.