When you think of sweetness, you automatically think of sugar and perhaps honey and maple syrup. But it is sugar that is such a common part of our world. Sugar makes the sweet taste buds zing. But is that why you are eating a candy? Are you eating it because you are bored and want something to do? Is your mouth dry and you want to get the saliva going? Are you running out of energy and want a quick boost?

Do you long for sweet things when you are not even hungry? One reason for sugar cravings, some scientists think, may be due to a chemical in the brain called serotonin, which makes you feel happy. Eating sugar is thought to help your body make serotonin, so it’s possible that eating something sweet may make you feel happy. Now if that is true, then the brain is always telling you to eat sweet things.

Sugar is full of energy. Boiled sweets are often pure sugar, so they don’t have any other any other ingredients, while chocolates, toffees and similar foods have butter as well, and butter is a source of fat. The fact that sugar (and fat) has lots of energy in is not a bad thing in its own right, but when the body gets too much energy food, it tucks the surplus away for a rainy day as fat, and that is where the problem could lie and it is one reason why we become, and stay, overweight .

Sugar has been used by some people in Asia for at least ten thousand years and now it is used by everyone everyday. It is in all kinds of foods, from bread to cake to ketchup, to baked beans and ready-meals. So even when we don’t add sugar from a bowl, we are most likely still eating it. Sugar comes from just two plants: sugar cane and sugar beet. Sugar cane is the plant that changed the course of history. The big changes in the world brought about by sugar almost all happened before sugar beet was even used, and that is why the first part of our history is only about sugar cane. However, sugar beet is now the sugar in almost every packet on supermarket shelves today. So our story will end with beets.

Sugar is very sweet. You don’t need much of it to sweeten even the bitterest of foods. It sweetens without changing the flavour of the food. It is a solid and does not need any special things like fridges to keep it in.

Because it can be stored easily, it can be transported around the world without too much trouble being taken to keep it fresh. It can be moved in bulk, by truck, by train and by ship, which makes it cheap to get from one place to another.

But despite all of these things, sugar started out as a luxury item – the most expensive spice of the Middle Ages. What made it change? Supply. At first only small amounts could be made. As a result it could be sold for lots of money and only the richest could afford it. But then things changed which made it cheap – and despite this, even more people made fortunes.

You may be used to sugar as little grains – granules – in a bowl. These grains are why common sugar is called granulated sugar. But do you know what trouble has to be gone through to get it like that? Changing raw sap from the sugar cane to transparent little granules on a spoon has been a mighty challenge down the ages. Raw sugar is crystals of sugar stuck together and coated in a brown liquid.

Some people in the world still make raw sugar in ways that have been used for over a thousand years.

The liquid is poured into pots and when it cools it goes hard. It is then knocked out of the pots and taken to local markets for sale.

This kind of sugar has much in common with the way that sugar was made all over South and East Asia many thousands of years ago.

The sugar is a hard, solid block and has to be broken with a hammer and then broken still further using something like pliers.

You can still find examples of old, hard sugar, known as sugar cones or sugar loaves in museums.

Sugar beet as a plant has been known for a long time. The Romans ate sugar beet because of its sweetness, but most people used it for its leafy growth and root, which they fed to animals.

Sugar beet is a root crop, meaning it grows in the ground and produces a swollen root like a swede or turnip. It can grow in places that have short, cool and wet summers, and it will therefore grow as far north as parts of Scandinavia and as far west as Ireland. It is very adaptable, and will also grow in the warm climate of California, provided it is well watered (irrigated). A sugar beet stores lots of sugar because it lives for two years. In the first year it grows but does not flower. Then it stores up lots of sugar in its root and keeps it there over the winter. This sugar would normally be used the following year to help the plant produce flowers, after which it would spread its seeds and die. Farmers harvest the root at the very end of the first year’s growth, when the root has most sugar. The important thing to know about sugar beets is that they are grown just like carrots or turnips in huge fields in long rows and harvested with big machines. They are also grown very close to where they will be eaten. As a result of this there is not likely to be any problem with sugar supply.

Getting the sugar out of the beet is different to getting sugar out of canes. The beet is sliced and put into hot water where it dissolves. After that, the refining process is identical, and refineries often receive raw sugar from both cane and beet sources.

Does sugar have any competition?

Because so few plants have lots of sugar in them, sugar cane and sugar beet have been without much competition – until modern times. Now it is possible to get sugar from maize and some other plants. Sugar from maize is called corn syrup and you will find it in many ready-made foods on supermarket shelves, but most of all in soft drinks. But the sugar we put in our coffee and cakes is still the sugar from sugar canes or sugar beets.