The Steffen House: A Molasses Deugarization Effort That Failed to Gain Traction

What happened to Steffen House, which was once a fundamental feature of beet sugar factories, especially in Europe? A Steffen house was considered so essential to the economic success of a beet sugar factory that a major player in the business of building and operating beet sugar factories in the early days of the 20th century, Henry Oxnard, said no I’d accept a contract to build a sugar factory unless it included a Steffen House.

A key measure of the performance of a beet mill back then and now is the percentage of sucrose in the molasses. The appearance of sucrose in molasses is evidence that the sugar destined for the warehouse ended up in molasses instead. In Oxnard’s time, molasses was considered a waste product and as such was often dumped into rivers adjacent to a sugar factory. Typically, in a standard factory lacking a Steffen House, or in this more modern period, an ion exchange process, the beet molasses will consist of fifty percent sucrose, an unacceptable loss for those in the business. of a beet factory. Factory overseers refer to the presence of sugar in molasses as “purity.” High purities, then, reflect high losses of sugar in molasses, as well as throwing money down the drain.

The production of molasses is generally equal to five percent of processed beet, therefore a production of 1,000,000 tons of beet could result in the production of 50,000 tons of molasses that would contain approximately 25,000 tons of sugar that would have a market value of ten million dollars. assuming sugar sells for $ .20 per pound, net of manufacturing costs. It goes without saying that preventing the loss of sugar in molasses is a fundamental challenge for managers of beet mills. Since the technology captured as much sugar as the existing equipment allowed, the next remedy was to remove the sugar from the molasses. That became the role of Steffen House.

The Steffen process was a method of extracting sugar from molasses invented by Carl Steffen, a Vienna-born Austrian who patented the process in 1883 while making sugar in Moravia. While his method has several variations, the process basically begins by diluting molasses with water (enough to create a 5-12% sucrose solution) and cooling it to a very low temperature (below 18 degrees C), after which Finely powdered lime (calcium oxide) in sufficient quantity to establish a 130 percent ratio to sucrose content is added continuously with stirring at a slow, uniform rate. Sugar is formed from molasses combined with lime and a sack of lime that is insoluble in liquid. The saccharate was then separated and washed on a filter press. The filter press cake (lime saccharate) was mixed with fresh water to a creamy consistency and took the place of milk of lime in the carbonation process.

About ninety percent of the sugar originally in beets was extracted in factories using the Steffen process. In some facilities, the wastewater from the Steffen process, which was rich in fertilizing qualities (mainly potassium sulfate), was used to irrigate the lands adjacent to the factory. The structure designed to accommodate the equipment used in the Steffen process became generally known in the industry as the “Steffen House”.

The Steffen process quickly gained popularity in Europe, but found less acceptance in the United States probably because the process was more sophisticated in terms of its associated chemistry than any process introduced in a beet factory up to that point. The first such process was installed in 1888 in Watsonville, California. It was a small pilot plant with three 5-foot refrigerators supplied by Grevenbroich Machinery Company of Germany. Grevenbroich eventually supplied much of the equipment for three pioneering California factories, Watsonville, Los Alamitos, and Chino, and continued to supply Oxnard’s Steffen process equipment until his company and Kilby Manufacturing of Cleveland, Ohio, began producing improved models a few years ago. later.

In the United States, the list of accomplished chemists holding leadership positions in beet factories was slim. Factory overseers often stuck to the tried and true technology of the past, preferring methods learned from experience rather than scholarship. Guided by practical experience rather than theory, they would without malice reject ideas and methods for which they lacked a basis for understanding. Watsonville’s Steffens experimental process was seldom used, for example, because the factory superintendent “didn’t believe in it.”

The main attraction of the Steffen process was its comparative advantage. Molasses was then an unwanted product and was presented more as a waste than as a salable product. Removing sugar from molasses was seen as getting good value from something that would otherwise be dumped into the river, a practice that from the earliest days of the beet industry in the US disapproved of those who depended on it. rivers for other industrial purposes, including fishing. Over time, molasses, which is basically a sugar syrup that has been through the factory several times and which, through the removal process, is mostly beet residues containing fifty percent sucrose, found a variety markets. At first, it became a source of ethyl alcohol, but it lost popularity for many years due to the low cost of foreign crude oil. Interest in ethyl alcohol production revived in the 1970s, when crude oil prices rose. Molasses is also a main raw material for the production of baker’s yeast and is an important source for the production of monosodium glutamate (MSG) and citric acid. However, the volume demanded by these users was low compared to the amount available by the country’s beet sugar companies. As a consequence, the price of molasses was low.

In the 1970s, attitudes about factory waste shifted from acceptance by the general public to almost total rejection of the premise that because of the good things factories do (they provide useful products and economic strength) ), your waste products must be tolerated. Therefore, the Steffens process, which produced liquid waste with high alkalinity and pH, as well as high organic content and consequent malodorous compounds, was not welcomed. A Steffens house discharged wastewater in amounts up to 800 percent of the volume of processed molasses.

Several studies indicated that it was possible to improve the strength of the odors emanating from Steffen’s waste. However, the cost of installing and operating effective systems would outweigh the economic gains provided by the process. So factory managers who used the Steffens process began shutting them down, and those who wanted the benefits of the process looked elsewhere. In addition to its shortcomings on the environmental front, the Steffens process recovered only about 60% of the sugar in molasses. Sugar manufacturers began looking elsewhere for a solution to the task of recovering sugar from molasses. The idea that it would be best to avoid making molasses in the first place crept into his thoughts. They resorted to ion exchange, a process that would prevent the manufacture of molasses in the traditional sense.

Ion exchange, or deionization, is a method of reducing impurities in the juice that then allows for more sugar extraction. The principle of ion exchange has been known for over 125 years, but is rarely used in the beet sugar industry due to its unfortunate habit of increasing the sodium content of sugar juices, delaying the ability to crystallize. of sugar. However, sugar manufacturers in recent days have turned to the practice of ion exclusion chromatography, which was first used successfully to produce high fructose corn syrup (HFCS). The process is based on the exclusion of ionic compounds and the inclusion of non-ionic compounds.

So molasses, once regarded as a thief capturing huge volumes of valuable sugar during the sugar manufacturing process, had finally been made to abandon its plunder through ion exchange, where sugar recovery rates reach ninety. percent compared to sixty percent in the country. Old Steffens House and no negative environmental impact. And yet another bonus awaited the sugar factories that resorted to ion exchange.

Modern factories that began in the 1990s began producing betaine from molasses, a valuable food additive with additional medicinal benefits. The University of Maryland Medical Center noted in one of its studies that inexpensive wines that use beet sugar to increase alcohol content contain betaine. Some experts suggest that this may explain why French wine drinkers tend to have low rates of heart disease despite diets high in fat and cholesterol. However, more convincing is the value of betaine as a feed supplement for chickens and pigs. Various experiments show that adding betaine to food improves performance. Furthermore, studies with pigs indicate an effect of betaine on energy metabolism and a strong increase in growth hormones. Humans are also finding uses for betaine as a food supplement under a different name, trimethylglycine, or TMG.

Thus, the Steffen process, once the savior of sugar manufacturing fell into disrepute due to cost and environmental concerns, gave way to a more efficient and environmentally friendly ion exchange.


GREAT WESTERN SUGAR COMPANY, The Technology of Beet Sugar Manufacture, The Great Western Sugar Company, Denver, Colorado, June 30, 1920 – an instruction manual prepared in large part by DJ Roach for use by operating employees of sugar factories company beet.

GUTLEBEN, Dan, The Sugar Tramp-1954- Michigan, Printed by: Bay City Duplicating Co, San Francisco, 1954

McGINNIS, RA (Ed.) 1982, Beet Sugar Technology, Fort Collins, Colorado, Beet Sugar Development Foundation

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