Science of Melting Sugar

• Sugar doesn't have a precise melting point, notes Baking911, citing a 2012 study done by scientists at the University of Illinois. Because the molecules of sugar break apart when they get hot enough to turn into a liquid, sugar isn’t truly melting, but rather decomposing. Sugar molecules break down before they get hot enough to liquefy, which means sugar is capable of caramelization at lower temperatures than previously thought. For example, sugar left in an oven heated as low as 225 degrees Fahrenheit can caramelize overnight. The discovery of sugar’s ability to caramelize without high heat means candy-makers can use different temperatures to manipulate the sugar molecules, gaining more control over the candy flavors.

Traditional Stovetop Methods

• Stovetop recipes for caramel usually say to use high heat until the sugar liquefies, usually at temperatures upwards of 380 F. Leaving the sugar on the heat causes it to brown, or caramelize, but once the process of browning starts, it’s easy to burn the sugar. Instead, use a lower heat, such as medium-high, and allow the sugar to decompose slowly. This gives you more control over the browning. Sugar begins to caramelize at 320 F; to stop the browning process, remove the pan from the heat and place it in an ice-water bath, letting the pot immerse halfway in the water for five seconds.

Using the Microwave

• Microwaving is a convenient way to melt sugar and chocolate quickly when making sweets. The trick to microwaving sugar is to watch the sugar closely. Because there is no exact temperature at which the sugar will melt, it must be removed from the heat as soon as if liquefies, or it will start to burn. Use a glass container to melt 1/2 cup of sugar at a time. Adding an acidic ingredient, such 4 or 5 drops of lemon juice, prevents the sugar from crystallizing, which leads to grainy candy. Microwave the sugar -- with or without 1 tablespoon of water -- on high heat and watch the bowl carefully. When you see multiple bubbles erupting on the surface of the sugar and a color change from light to dark, stop the microwave.

Dry Melting

• For hard candy, such as peanut brittle, you need to melt the sugar without adding water. Without the water in the sugar, no crystals form when the sugar hardens, resulting in a smooth, glassy candy. Melting sugar without water requires a sturdy, wide-bottomed pot. Warm the pot before adding the sugar, and use medium-high heat. As the sugar slowly heats, the outer edges melt first. Swirl the pan to promote even melting, and remove it from the heat as soon as the sugar turns a light golden-brown.