Whatever happened to the Steffen House, once a critical 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 beer sugar factories in the earliest days of the 20th Century, Henry Oxnard, said he would not accept a contract to build a sugar factory without it included a Steffen House.
A key measurement of a beet factory's performance then and now is the percent of sucrose in molasses. The appearance of any sucrose in molasses is evidence that sugar intended for the warehouse, ended up, instead, in molasses. In Oxnard's day, molasses was deemed a waste product and as such was often poured into the rivers abutting a sugar factory. Typically, in a standard factory lacking a Steffen House, or in this more modern period, an ion-exchange process, beet molasses will consist of fifty percent sucrose, an unacceptable loss to those engaged in the management of a beet factory. Factory superintendents refer to the presence of sugar in molasses as "purity". High purities, then, reflect high sugar losses to molasses – the same as pouring money down the drain.
Molasses production is generally equal to five percent on beets processed, so a factory run of 1,000,000 tons of beets could result in the production of 50,000 tonnes of molasses which would contain roughly 25,000 tons of sugar which would have a market value of ten million dollars, assuming sugar is sold at $ .20 per pound, net of manufacturing costs. It should go without saying that the prevention of the loss of sugar to molasses is a paramount challenge to beer factory managers. Since early, technology captured as much sugar as permitted by equipment then extant, the next curative was to remove sugar from molasses. That became the role of the Steffen House.
The Steffen process was a method for extracting sugar from molasses invented by Carl Steffen a Vienna born Austrian who patented the process in 1883 while engaged in sugar manufacture in Moravia. While his method has several variations, the process basically begins by diluting molasses with water (enough to create a solution of 5-12% sucrose) 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 relationship of 130 percent to the sucrose content is continuously added with agitation at a uniform and slow rate. The sugar in the molasses combines with the lime and a saccharage of lime is formed which is insoluble in the liquid. The saccharate was then separated and washed in a filter press. The cake from the filter press (saccharate of lime) was mixed with sweet water to a consistency of cream and took the place of milk of lime in the carbonation process.
About ninety percent of the sugar originally in the beet was extracted in those factories that employed the Steffen process. In some facilities, the waste water from the Steffen process, which was rich in fertilizing qualities (primarily potassium sulfate), was used for irrigating lands adjoining the factory. The structure designed to accommodate the equipment employed in the Steffen process became generally referred to in the industry as the "Steffen's House".
The Steffen process won quick popularity in Europe but found less favor in the United States most likely because the process was more sophisticated in terms of its associated chemistry than any process introduced into a plant factory up until that time. The first such process was installed in 1888 at Watsonville, California. It was a small pilot plant with three 5-foot coolers supplied by the Grevenbroich Machinery Company of Germany. Grevenbroich ever provided much of the equipment for three pioneer 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 later.
In the United States, the roster of accomplished chemists who held lead positions in beer factories was slim. Often factory superintendents hewed to tried and true technology of the past, preferring methods learned from experience rather than scholarship. Guided by practical experience instead of theory, they would without malice reject ideas and methods for which they lacked a basis for understanding. The Watsonville experimental Steffens process was little used, for example, because the factory superintendent "did not believe in it."
The primary attraction of the Steffen process lay in comparative advantage. Molasses was then an unwanted commodity and presented itself more as a waste issue than a salable product. Removing sugar from molasses was regarded as getting good value from something that would otherwise be discharged into the river, a practice that was from the earliest days of the US beet industry fronned upon by those who relied upon rivers for other industrial purposes, including fishing. In time, molasses, which is basically a sugar syrup that has been through the factory a number of times and is by the process of elimination mostly sugarbeet waste containing fifty percent sucrose, found a variety of markets. Early on, it became a source of ethyl alcohol but lost favor for many years because of the low cost of foreign crude oil. Interest in ethyl alcohol production would revive in the 1970's when crude oil prices rose. Molasses is also a principal raw material for the production of baker's yeast and is a major source for the production of monosodium glutamate (MSG) and citric acid. However the volume demanded by those users was low compared to the quantity made available by the nation's beet sugar companies. The price of molasses was low as a consequence.
The 1970's saw attitudes about factory waste change from acceptance by the general public to a near total rejection of the promise that because of the good factories do (provide useful products and economic strength) their waste products must be tolerated. Thus the Steffens process which produced liquid waste bearing high alkalinity and pH as well as high organic content and consequent malodorous compounds became unwelcome. A Steffens House discharged waste water in amounts as great as eight hundred percent of the volume of molasses processed.
Various studies indicated that it was possible to ameliorate the strength of the odors emanating from Steffen waste. The cost, however, to install and operate effective systems would offset the economic gains provided by the process. Thus factory managers who employed the Steffens process began shutting them down and those who desired the benefits of such a 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. Seeping into their thoughts was the idea that it would be better to avoid making molasses in the first place. They turned to ion exchange, a process that would forestall the making of molasses in the traditional sense.
Ion exchange, or deionization, is a method of reducing impurities from juice which then allows for increased extraction of sugar. The principle of ion exchange has been known for more than 125 years but seldom used in the beet sugar industry because of its unfortunate habit of increasing the sodium content of sugar juices which retards the ability of sugar to crystallize. However, later-day sugar manufacturers 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 nonionic compounds.
Molasses, then, once considered as a thief who captured large volumes of valuable sugar during the sugar manufacturing process had been made, at last, to give up its plunder via ion exchange where the sugar recovery rates reach ninety percent compared to sixty percent in the old Steffens House and without negative environmental impact. And yet another bonus awaited sugar factories that turned to ion exchange.
Modern factories beginning in the 1990's began producing betaine from molasses, a valued 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 the alcohol content, contain betaine. Some experts suggest that this may explain why wine drinkers from France tend to have low rates of heart disease despite diets high in fat and cholesterol. More cogent, however, is the value of betaine as a feed supplement for chickens and pigs. A number of experiments show that the addition of betaine to the feeds improves performance. Also, studies with pigs indicate an effect of betaine in energy metabolism and a sharp increase in growth hormones. Humans, too, are finding uses for betaine as a food supplement under a different name, trimethylglycine or TMG.
Thus, the Steffen process, once the savior of sugar manufactures fell into disrepute because of environmental and cost concerns but made way for the 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 greatly by DJ Roach for use by the operating employees of the company's beet sugar factories.
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