What Sweets Are Made Of

Almost every sweet in the shop is a variation on the same four things: sugar, glucose syrup, water, and something to set or flavour it. What separates a toffee from a fudge, or a marshmallow from a jelly, is temperature and technique rather than an exotic ingredient list.

This is the biggest area of search in the whole set. Marshmallow, liquorice and toffee alone account for 334,090 searches a month, and almost all of it is answered by recipe sites rather than by anyone who actually sells the things.

Why glucose syrup is in everything

If you read enough labels you will notice glucose syrup in nearly all of them, and it is easy to assume it is a cheap filler. It is not. Glucose syrup stops sugar recrystallising. Pure sucrose, boiled and cooled, wants to form crystals again; glucose gets in the way of that and keeps the texture smooth.

Without it, most soft sweets would set hard and grainy instead of staying chewy. It is the difference between fudge and a lump of sugar. It is also why an old sweet that has been through a warm cycle goes gritty — the glucose has stopped winning.

Temperature is the recipe

The single biggest determinant of what a sugar confection becomes is how hot the syrup got before it was cooled:

• 112–116°C — fudge and fondant. Enough water left for a soft, crystalline set.
• 115–120°C — marshmallow. Whipped with a setting agent while hot, trapping air.
• 120–130°C — toffee and caramel. Chewy, with the sugars beginning to brown.
• 145–155°C — boiled sweets. Almost all water driven off, so it sets glassy and snaps.

That is why toffee, fudge and caramel are genuinely different things rather than regional names for the same thing, and why the same four ingredients produce a completely different sweet a few degrees apart.

Air is an ingredient

A marshmallow is roughly half air by volume, whipped into hot syrup and held there by gelatine as it cools. That is why a large bag weighs so little, why the price per kilo looks higher than it feels in the hand, and why marshmallows behave so oddly when heated — the gelatine melts at close to body temperature while the sugar around it does not.

See what are marshmallows made of and, if you are cooking with them, how to melt marshmallows.

Sour is a coating, not a flavour

The sourness on a sour sweet is an acid dusted or sprayed onto the outside — usually citric, malic or tartaric. Different acids hit at different speeds and last for different lengths of time, which is why some sours are sharp instantly and others build and then fade. It is also why unwrapped sour sweets go tacky in a cupboard: the acid coating is hygroscopic and pulls moisture out of the air.

What makes sweets sour? goes through the individual acids and what each one does to your mouth.

Liquorice is a root, and it is not aniseed

Liquorice is made from the root of Glycyrrhiza glabra, a plant whose active compound is roughly fifty times sweeter than sugar and tastes like nothing else on the shelf. Most people who say they dislike liquorice are describing aniseed, which is a different plant with a superficially similar flavour.

It also has a genuine pharmacology, which is why there is official guidance about eating large amounts of it regularly. What is liquorice? covers the plant, the styles, and the salted variety that divides people.

The white film on chocolate is not mould

It is bloom — fat or sugar that has migrated to the surface after a temperature change. It affects appearance and texture and not safety, and it is why chocolate that has sat in a warm car looks chalky afterwards. Why chocolate turns white explains which of the two kinds you have and whether it still tastes right.

Shop the things in this section

Marshmallows, liquorice, toffee and fudge, fizzy and sour, chocolate. Every one carries its full ingredient declaration on the product page.