I also really don't like the taste of UHT milk (called "H-Milch" in German). For me it's undrinkable. I can also taste the difference in a cappuccino. Interestingly, like the_mitshuiko already said, UHT milk is not very common in Austria but extremely common in Germany. When I'm in Germany, I have a hard time finding a coffee shop that doesn't serve coffee with UHT milk. It is basically impossible and to be honest, it says a lot about the German food culture. In Austria, not even McDonald's uses UHT milk in its McCafes but in Germany, even the most expensive coffee shop with coffees for 4 € and up cheap out on the milk.