My parents were living on a base in Germany when my brother was born. Sometimes they bought American milk, and sometimes they bought German milch, which is processed differently than American milk.
When my brother, then a baby, was given a bottle of milch, he would happily suck it down within a short period of time. When he was given American milk, however, it was another story. He would take a sip, then throw it down as though utterly disappointed by it. After several minutes, he would pick up the bottle again, give it an experimental suck, then throw it down again, disgusted by the inferior liquid. It would often take him well over an hour to finish a bottle of the American milk.