The first form in which sugar was produced was as sugar loaves. These were the purest form of sugar. Sugar loaves were made by pouring pure cane sugar into a cone-shaped mould with a small hole in the bottom for expelling the excess liquid. The moulds were hung to dry for a couple of weeks until the crystals settled.
The Persians used hollowed-out bamboo canes as moulds for drying sugar in. The Egyptians used glass sugar loaf moulds, and the Chinese were the first to use ceramic moulds. The Europeans used wooden moulds for many years, and later went over to using clay. However, both clay and wood are fairly brittle materials, so with the onset of industrialisation, steel or zinc moulds began to be used instead. These moulds had a clasp on the side so that they could easily be opened and the sugar loaf removed after solidifying.
Sugar loaves weighed between 5 and 15 kilos. Of course, this was far too great a quantity for individual consumers – and also far too expensive. Instead, pieces were broken off as required. The large sugar loaves were also rather cumbersome to handle. The loaves started being cut into slices for retail use, which made them easier for both merchants and consumers to handle.
Centrifugation was introduced around 1900. This method allowed the sugar mass (massecuite) to be dried more quickly. Instead of hanging the sugar loaves up to dry in drying rooms, they were spun in a centrifuge in their traditional cone-shaped moulds. Once dried, they were removed from the moulds and packaged.
Sugar loaves stopped being produced in Denmark and Sweden around 1940. Instead, the sugar was reduced to fine particles, and today's granulated sugar was born. Merchants continued selling sugar loose by weight until 1955. After this, sugar began being sold in the 2 kilo packages we know today.
Sugar loaves can still be bought in some places. They are smaller today – weighing roughly 250 g – and are imported from Germany.
[Source: Gertrud Helgesson of Arlö Sugar Museum and Erik Jørgensen of Nakskov Sugar Museum]