I am munching on a sheep's-milk gouda (aged two years) that has a very crumbly/dry texture and a sharp bite, with a smoooooothe sweet caramel flavor...indeed, as tomer says, a Maillard-reaction type sweetened aftertaste that typically comes from browning (or caramelizing sugars in low heat), allowing the fructose-based energy stores to begin breaking down into shorter-chain sugars that our tongues can recognize as the sweet/caramel flavor. The cheese is called Ewephoria (from Friesland, Holland). It is magnificent!
Yes, my yogurt make sometimes gets forgotten during the high-temp phase and it develops a caramel-like layer of goo on the bottom of the pot, almost like manjar blanco (in Spanish).