using the simplified research of WikiQuotehttp://en.wikipedia.org/wiki/Nucleate_boilingDNB is the rolling boil we use, so temps from 212+54 = 266F to 212+220 = 432F
DNB is also known as Transition boiling, unstable film boiling, and partial film boiling. For water boiling as shown on the graph, transition boiling occurs when the temperature difference between the surface and the boiling water is approximately 30 °C (54 °F) to 120 °C (220 °F) above the TS. This corresponds to the high peak and the low peak on the boiling curve. The low point between transition boiling and film boiling is the Leidenfrost point.Quotehttp://en.wikipedia.org/wiki/CaramelizationThe conclusion I draw is that carmelization is possible in a boil kettle with a 266F to 432F temp on the kettle surface where the Temps are the highest.
The process is temperature-dependent. Specific sugars each have their own point at which the reactions begin to proceed readily.
Caramelization temperatures Sugar Temperature
Fructose 110°C, 230°F
Galactose 160°C, 320°F
Glucose 160°C, 320°F
Sucrose 160°C, 320°F
Maltose 180°C, 356°F
The caramelization reactions are also sensitive to the chemical environment. By controlling the level of acidity (pH), the reaction rate (or the temperature at which the reaction occurs readily) can be altered. The rate of caramelization is generally lowest at near-neutral acidity (pH around 7), and accelerated under both acidic (especially pH below 3) and basic (especially pH above 9) conditions.
without question Maillard reactions also occur.
The steam is that hot but what about the sugars? My intuition is that the sugars remain dissolved in the wort because I don't see caramel on the inside bottom of the pot. I do often see coagulated protein, which is not soluble, on the bottom of the pot.