How to make rich, flavorful caramel without melting sugar

I'd always thought of caramel as being produced when sugar melted. I figured it had something to do with the Maillard reactions - though that needs proteins and sugars reacting together.

Turns out that caramelization is based on thermal decomposition which is - to quote Serious Eats...

...on the other hand, is a chemical reaction that breaks down molecular bonds to produce new substances. While it's not a perfect analogy, imagine a pile of grass clippings releasing carbon dioxide as it turns to mulch in the sun—an irreversible process with variable results (i.e., no two handfuls of mulch are exactly alike, or composted to the same degree). Instead of occurring at a specific point, thermal decomposition occurs over a range of temperatures determined by the intensity and duration of heat.

That doesn't call for any melting at all. All you have to do is heat the sucrose up high enough that it starts to decompose into other compounds.

In fact, caramel is so unlike sucrose, C12H22O11, that its nature can't be expressed by a single chemical formula. Instead, it's a mixture of caramelan (C15H18O9), caramelane (C12H9O9), caramelen (C36H48O24), caramelene (C36H25O25), caramelin (C24H26O13), and over a thousand other compounds "whose names," one scholar lamented in 1894, "science seems to have invented in a fit of despair."

In fact...

Despite a modest progression of color, the sugar goes through extreme changes in flavor every step of the way. With only one hour of toasting, it mellows with a complexity totally unlike plain sugar. After another hour, it's evocative of caramel the same way unrefined sugar hints of molasses, surely but subtly.

Within three hours, thermal decomposition liberates enough water that the sugar begins to clump as stronger caramel notes develop, changes that intensify into hour four. At five hours, the clumping effect makes granulated caramel visually identical to light brown sugar, but with a unique flavor of its own. Though undeniably caramel, it lacks the bitter notes synonymous with high-heat techniques, giving it a lighter profile. Beyond that point, thermal decomposition will finally liquefy the sugar.

Check out the full recipe and science over at Serious Eats.