Amber-coloured caramel, used as a sauce or a crisp sweet, forms when heavy sugar syrup is heated beyond the hard-crack stage, all the moisture has evaporated, and the syrup takes on a deep brown colour. Light caramel is mild-flavoured; medium caramel is dark golden brown and has a nutty taste. Take care not to cook the caramel beyond 190°C or it will burn. If the caramel sets too quickly, re-warm it briefly.
Bring heavy syrup to the boil in a heavy pan. Lower the heat and swirl the pan once or twice so the syrup colours evenly; do not stir.
When the caramel is the required colour, plunge base of pan into iced water to stop further cooking; remove pan before caramel sets.