What Sugar Does Besides Sweeten

Sugar has four jobs

Halve the sugar in a recipe and you expect it to be less sweet, but the colour and texture change too. Sugar is doing four things at once.

• Sweetness
• Colour and aroma — caramelisation, and fuel for the Maillard reaction
• Moisture retention, since sugar holds on to water
• Structure: in baking it interferes with gluten and protein setting, which is what makes things tender

Reduce the sugar in a cake and it comes out firmer and stales faster — not because it is less sweet, but because the last two jobs went away.

Caramelisation and Maillard are different reactions

• Caramelisation needs only sugar. Around 160C it breaks down into colour and bitter aromatics.
• The Maillard reaction needs sugar and protein (browning and maillard). It starts at far lower temperatures and produces a much wider set of aromas.

A little sugar rubbed on meat browns faster because it supplies Maillard with more to work with. The glossy brown of teriyaki chicken or hong shao rou is both reactions running together.

The flip side: sugar burns easily. A sweetened glaze cannot sit over high heat for long.

Judge caramel by temperature, not colour

By the time you see the colour you want, you are late. Roughly:

• 110-115C: syrup, still colourless.
• 150C: pale gold; aroma starts here.
• 170-180C: amber, where most caramel sauces live.
• Above 190C: bitter, and unrecoverable.

The pan carries it another 20-30C after the heat is off, so pull it one stage early rather than at the colour you are aiming for.

Sugars do not substitute for one another

• White sugar is pure sucrose. Having no other flavour, it stays out of the way.
• Brown sugar, jaggery and palm sugar retain molasses, which is mildly acidic and carries minerals — so it changes reactions, not only taste. Jaggery in vindaloo is there for its bitter finish as much as its sweetness.
• Swapping white for brown in baking removes that acidity, leaving bicarbonate of soda with nothing to react against. The rise changes.

In savoury cooking, sugar is not there to sweeten

A teaspoon of sugar is routine across Korean, Chinese and Southeast Asian cooking because it damps down salt and acid. It is how you lower perceived saltiness without removing salt, and how you round off the edge of vinegar (balancing flavour).

The 150ml of vinegar in vindaloo, the shrimp paste in laksa, the vinegar and soy in yuxiang eggplant — leave the sugar out of any of them and each strong element steps forward on its own. Taste with and without and you will not notice sweetness; you notice that nothing else is sharp any more.

If you want to cut it

In desserts, about 20% is the safe margin. Beyond that brownies turn dry and tiramisu loosens, because you are removing the structural share along with the sweetness.

Savoury cooking is far more forgiving. If the sugar is there for balance, halve it and pull back slightly on the acid to match.