Why Is Sugar Sweet?

Step 1 of 5

Sweetness happens on your tongue, not in the sugar.

Your tongue is covered in receptors shaped to catch particular molecules. Sugar fits the sweet ones, a nerve fires, and your brain calls it sweet. The sugar itself has no flavour to give.

Step 2 of 5

Other shapes fit the same lock.

Anything that fits that receptor tastes sweet, whether or not it is sugar. Some artificial sweeteners fit far better than sugar does, which is why a tiny amount tastes intensely sweet.

Step 3 of 5

Plants make it out of sunlight.

A leaf takes air, water and light and builds sugar. Every scrap of sugar in your kitchen was assembled by a plant in the sun, then squeezed out of cane or beet.

Step 4 of 5

It is the fuel almost everything runs on.

Your muscles and brain run on sugar carried in your blood. So do plants at night, and so do the yeast in bread and the bacteria on your teeth — which is where the trouble starts.

Step 5 of 5

Heat turns it into something else.

Warm sugar past melting and it browns, changing into hundreds of new compounds with a deep flavour that raw sugar has none of. That is caramel, and it is why toast and roast food taste as they do.

Honey is mostly two sugars and water. Bees turn flower nectar into it by evaporating most of the water off, which is why it never spoils.