糖炒久了，为什么会变焦色？

Sugar starts as clean white crystals. 糖一开始是干干净净的白色晶体。 When it gets very hot, it changes itself. 加热到高温，它自己会发生变化。 This is called caramelization. 这就叫焦糖化反应。 Its color turns from white to light gold. 颜色从白色变成浅金色。 Soon it becomes deep amber and smells sweet. 很快变成深琥珀色，还香香的。 That is how caramel is born. 焦糖就是这样做出来的。