Sugar has been extracted from sugar beets cultivated in Germany for over 200 years. Much has changed since then. For instance, in 1836 it took twenty kilograms of beets to produce one kilogram of sugar, whereas today, only seven kilograms are required.
From beets to sugar
If you were to measure the time it takes to produce shimmering white sugar crystals from a beet that had just been delivered from the field to the factory, you would be surprised: On average, it takes less than eight hours.
From the field to the sugar package: the steps required to extract sugar
Sugar beet harvesting begins in September. The entire process is referred to as "the campaign". Samples are taken from each load of beets delivered to determine sugar content and other important elements. The amount of soil still on the beets is also analyzed. The prices paid for the beets and feedback given to beet farmers are determined based on the results of these tests. The beets are unloaded either by dumping or using a water jet. After being thoroughly washed, they are sent directly to the processing line or to the storage facility.
The beets are sliced into thin strips, preheated in a cossette scalder and are then sent to an extraction tower. Water at 70° Celsius is poured through the device to extract the sugar and produce raw juice. The used cosettes are dried by means of screw presses and hot air.
A lime kiln is used to produce the natural substances lime and carbon dioxide, which are added sequentially to the raw juice to bind and precipitate out the non-sugar impurities. A clear, thin juice with a sugar content of about sixteen percent remains.
The thin juice is concentrated by heating to make a thick golden brown juice with a sugar content of about sixty-seven percent.
The thick juice is boiled until crystals are formed, which are a glowing golden yellow color because they are covered with syrup. The syrup is separated from the crystals in a centrifuge. Hot water is used to rinse off any residual syrup. The remaining sugar crystals are clear as glass, and the light refracted from them is white as snow. This sugar is dissolved and re-crystallized to produce refined sugar - sugar that is extremely pure.
The finished sugar is dried, cooled and stored in silos, and is subsequently withdrawn and further processed or packed. Over eighty percent of the sugar is shipped to the converting industry, which uses it to make confectioneries, beverages, baked goods, etc. Just under twenty percent of the sugar is converted to various types of household sugar and packaged.
All the by-products of this process are returned to the natural cycle. The pressed slices of sugar beet are used as animal feed. The "Carbokalk" [carbolic lime] that is a by-product of processing the juice is an excellent fertiliser.
Sugar processing diagram (PDF, 88.38 KB)