Sugar beet

A sugar beet is a special kind of plant whose root has lots of sucrose, a type of sugar that people use every day. Farmers grow sugar beets to make sugar, and this plant is very important for sugar factories. It is part of a big plant family that also includes foods like beetroot and chard. Even though it looks similar to these vegetables, the sugar beet is different because it has much more sugar.

Sugar beets grow best in cooler places where it is too cold for another sugar plant called sugarcane. In 2024, two countries, Russia and Germany, grew the most sugar beets in the world. Together, they helped make up a huge amount of sugar—294 million tonnes. The rest of the world’s sugar mostly comes from sugarcane, but sugar beets are very important too, especially in colder regions.

Description

The sugar beet has a conical, white, fleshy root (a taproot) with a flat crown. It also has a rosette of leaves. Sugar is made by photosynthesis in the leaves and is stored in the root.

The root of the beet contains 75% water, about 20% sugar, and 5% pulp. The sugar in sugar beets can range from 12% to 21%, depending on the type of plant and how it is grown. Sugar is the main reason people grow sugar beets as a cash crop. The pulp, which does not dissolve in water and is mostly made of cellulose, hemicellulose, lignin, and pectin, is used to feed animals. Other parts of the sugar beet crop, like pulp and molasses, add about 10% more value to the harvest.

Sugar beets grow only in temperate areas, unlike sugarcane, which grows in tropical and subtropical zones. A sugar beet usually weighs between 0.5 and 1 kg (1.1 and 2.2 lb). The leaves of the sugar beet are rich green and grow to about 35 cm (14 in) tall. The leaves grow in a cluster from the top of the beet, which is often at or just above the ground.

History

Discovery

Main article: Beta vulgaris

The beet plant has many types. In the 1500s, a French scientist named Olivier de Serres found a way to make syrup from red beetroot. He said the juice looked beautiful because of its red color. But because sugar from sugar cane tasted better, this idea didn’t become popular.

Modern sugar beets started in the 1700s in Silesia. The king of Prussia, Frederick the Great, helped scientists try to make sugar from beets. In 1747, a scientist named Andreas Sigismund Marggraf found sugar in beetroots. He showed that this sugar was the same as sugar from sugar cane. The best beet for sugar was the white beet. But his work didn’t lead to making sugar from beets for sale.

Development of the sugar beet

Franz Karl Achard, a student of Marggraf, began growing sugar beets in Kaulsdorf near Berlin in 1786. He tested 23 types of beets and picked one from Halberstadt in today’s Saxony-Anhalt, Germany. This beet was named weiße schlesische Zuckerrübe, meaning white Silesian sugar beet. Around 1800, it had about 5% to 6% sugar. This beet became the basis for all modern sugar beets. Since then, scientists have kept improving them, and today’s beets have about 18% sugar.

Beet sugar industry

Main article: Beet sugar factory

In 1801, Franz Karl Achard opened the world’s first factory to make sugar from beets in Kunern, Silesia (now in Poland). Soon, people in France began making sugar from beets too, especially because it was hard to get sugar from sugar cane during wars. By 1840, about 5% of the world’s sugar came from beets. By 1880, that number grew to over 50%. In North America, the first factory opened in 1879 in Alvarado, California. German settlers brought sugar beets to Chile around 1850.

Culture

The sugar beet, like sugarcane, needs special soil and climate to grow well. The soil should have lots of nutrients, be rich in humus, and hold moisture. It should also be fairly level and drain well, especially where irrigation is used.

Sugar beets grow best in sandy loam soil—a mix of organic matter, clay, and sand. They can grow in sandy soil or heavy loams, but not in soil with gravel or hardpan. The best temperatures for sugar beets are between 15 to 21 °C (59 to 70 °F). They need about 460 mm (18 inches) of rain if there is no irrigation. High winds can harm young beets by crusting the soil. The best places to grow sugar beets are along the coast of southern California, where warm days and cool nights help them grow. In places like Idaho, Colorado, and Utah, the high daytime temperatures and cool nights also produce excellent sugar beets. In Michigan, long summer days and the influence of the Great Lakes create good conditions for sugar beets.

Production

In 2024, the world produced 294 million tonnes of sugar beets. The top producers were Russia and Germany.

Sugar extraction

Most sugar beets are used to make white sugar. This happens in a place called a beet sugar factory, sometimes just called a sugar factory. Today, these factories often also clean and finish the sugar, but in the past, they made raw sugar and another place cleaned it to make white sugar.

In the 1960s, making sugar from beets had these steps:

• Harvesting and storing the beets carefully
• Washing and cleaning them to remove dirt
• Cutting the beets into small pieces
• Taking the sugar out, leaving behind beet pulp

Now, most factories clean the sugar themselves. The beet pulp is used to make food for cattle.

The steps to turn this into white sugar are the same whether you start with sugar beets or sugar cane:

• Cleaning the juice to take out impurities
• Heating the juice to make it thicker
• Turning the juice into sugar crystals by boiling it
• Separating the crystals from the liquid in a machine called a centrifuge
• Boiling the leftover liquid to get more sugar and a thick, sweet syrup called molasses

Ethanol production

From molasses

There are two ways to make alcohol called ethanol from sugar beets. The first way makes alcohol as a side product when making sugar. This is done by fermenting the sugar beet molasses left after cleaning the sugar. This process is similar to how rum is made from sugar cane molasses. In some countries, like the Czech Republic and Slovakia, this method is used to make a rum-like drink called Tuzemak. On the Åland Islands, a similar drink is made called Kobba Libre.

From sugar beet

The second way to make alcohol is by directly fermenting sugar beets without first turning them into sugar. The idea of making alcohol this way started soon after the first sugar beet factory was built. Between 1852 and 1854, someone named Champonnois created a good way to make alcohol from sugar beets. Soon after, many factories to make alcohol from sugar beets appeared in France. Today, the steps to make alcohol from sugar beets are:

• Adding Starch milk
• Liquefaction and Saccharification
• Fermentation in special vats
• Distillation
• Dehydration, which makes Bioethanol
• Rectification
• Refining, which makes a very pure alcohol

Large factories that make alcohol from sugar beets are mostly found in Europe. In 2023, a company called Tereos had 8 such factories in France, Czechia, and Romania.

In many European countries, the clean alcohol made from sugar beets is used to produce drinks like vodka, Gin, and others.

Other uses

Sugary syrup

An unrefined sugary syrup can be made directly from sugar beet. This thick, dark syrup is created by cooking shredded sugar beet for several hours, then pressing the resulting mash and concentrating the juice until it has a consistency similar to honey. No other ingredients are used.

In Germany, particularly the Rhineland area, and in the Netherlands, this sugar beet syrup (called Zuckerrüben-Sirup or Zapp in German, or Suikerstroop in Dutch) is used as a spread for sandwiches, as well as for sweetening sauces, cakes and desserts. Dutch people generally top their pancakes with stroop.

Uridine

Uridine can be isolated from sugar beet.

Alternative fuel

BP and Associated British Foods plan to use agricultural surpluses of sugar beet to produce biobutanol in East Anglia in the United Kingdom.

Cattle feed

In New Zealand, sugar beet is widely grown and harvested as feed for dairy cattle. It is regarded as superior to fodder beet, because it has a lower water content (resulting in better storage properties). Both the beet bulb and the leaves (with 25% protein) are fed to cattle. Dairy cattle in New Zealand can thrive on just pasture and beets, without silage or other supplementary feed. The crop is also now grown in some parts of Australia as cattle feed.

Agriculture

Sugar beets are an important part of a crop rotation cycle.

Sugar beet plants can get sick from Rhizomania ("root madness"), which changes the big root into many small roots. This makes the crop hard to use for sugar. Rules in European countries try to stop it from spreading, but it is already in some places. The plants can also get sick from the beet leaf curl virus, which makes the leaves curl and grow poorly, and from beet yellows virus.

Scientists are always looking for new types of sugar beets that can resist these sicknesses and give more sugar. In the United States, important research happens at different USDA farms, such as in Fort Collins, Colorado, Fargo, North Dakota, and Michigan State University in East Lansing, Michigan.

Other important plants in the same family include:

• Beetroot
• Chard
• Mangelwurzel or fodder beet

Genetic modification

Main article: Genetically modified sugar beet

In the United States, scientists created genetically modified sugar beets that can survive a special weed-killing spray called glyphosate, made by Monsanto. This was allowed by the government in 2005 for farming. Sugar from these modified beets is safe to eat and has the same nutrition as regular sugar. Most sugar beet farms in the U.S. used these modified beets by 2011.

Farmers can spray glyphosate to kill weeds without hurting the sugar beet plants. However, some people worried that these modified beets might mix with regular beets. A court once said they could not be planted, but later allowed it again.

Genome and genetics

The sugar beet's DNA has been studied and mapped out. Its genome is about 731 Megabases in size and is found in 18 chromosomes. Most of its DNA is made of repeated pieces spread across these chromosomes.

Wild beet plants have also been studied. This helped scientists find a gene that can protect sugar beets from a disease called rhizomania, which can harm the plants.

satellite DNA LTR retrotransposons

Breeding

Sugar beets have been carefully grown to have more sugar, going from 8% to 18% in the past 200 years. They have also been bred to resist diseases and to grow bigger roots. Scientists found a special line that helps make breeding easier and improves the amount of sugar beets grown.