Serious Eats: How to Make Rich, Flavorful Caramel Without Melting Sugar by Stella Parks.

“Melting is a phase change that has no impact on chemical composition, like the transition from ice to water. […]
Thermal decomposition, on the other hand, is a chemical reaction that breaks down molecular bonds to produce new substances. […]
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.'”

(Finally there’s a reason to learn organic chemistry. ;-) )

Harold McGee (of “On Food and Cooking” fame): Caramelization: new science, new possibilities.

“How does heat turn sugar into caramel? Heat is a kind of energy that makes atoms and molecules move faster. […]
That’s what I’ve thought for many years, along with most cooks and confectioners and carbohydrate chemists: heat melts sugar, and then begins to break it apart and create the delicious mixture we call caramel.
And we’ve all been wrong.”

Link via MetaFilter.

I think I will need to try to use caramelized sugar in shortbread, which I love. By the way, the secret to shortbread with that great crumbly texture is to substitute one of the three parts of flour with rice flour:

Shortbread:

Ingredients:
375g flour: 250g wheat flour, 125g rice flour
250g butter
125g sugar
vanilla aroma
pinch of salt (flaky sea salt works best)

Mix everything into a dough, don’t knead too much. Spread onto a baking sheet (23cm x 30cm) lined with baking paper and mark rectangles, pierce each rectangle twice with a fork. Bake for 50 minutes at 150°C (300°F), then cut into rectangles while still hot. The shortbread should have a little bit of color, but not too much.

Recipe found at German cooking/baking weblog Chili & Ciabatta and translated to English. See also here.