The tall red brick building on the north side of U.S. Highway 90A between Main Street and Ulrich Street has been in the news lately, because PUMA Development requested support from the City of Sugar Land and the Sugar Land Economic Development Corporation in order to preserve the structure known as the “Char House”. Long considered Sugar Land’s most iconic building, the Char House has been a landmark, first for the Imperial Sugar refinery and then for the City of Sugar Land for almost 100-years. But how many current residents of Sugar Land know the purpose of the Char House in refining sugar? An article in the March 1953 issue of the Imperial Crown, published by the Imperial Sugar Company provides the answer – the Char House “Gives Sugar Clear Color”.
A SHORT HISTORY OF SUGAR
As explained in the article, centuries ago, before the New World was discovered, European explorers, Crusaders, and other travelers returning from India and the Middle East brought with them an ingredient used in food that was sweet to the taste. This sweet ingredient eventually became known as “sugar”. It was an expensive ingredient and for many years it was only available to royalty and the affluent.
Over the years, as sugarcane cultivation expanded around the world, sugar became more available to the masses. Sugarcane was brought to the Americas in the 15th century, arriving first in Brazil by way of Portuguese traders. The first sugar cane planted in the New World was a gift from the governor of the Canary Islands to Christopher Columbus, according to the Imperial Crown article.
Sugar became a basic food, but it did not resemble the sugar of today– it was “raw” sugar, not “refined”. Raw sugar is the result of extracting the juice from sugarcane and boiling it until nearly all the moisture evaporates. Raw sugar retains all the minerals and acid impurities of the sap it came from, which gives it a distinctive, sometimes undesirable, taste. It can be various shades of brown and has a coarser texture than refined sugar.
REFINING THE RAW SUGAR
By the early 1800s, the demand for sugar prompted refiners to constantly seek better methods for refining it. In 1818, a material made from powdered, burned animal bones was added to some bright amber liquid sugar. After the “bone char” was filtered out, the sugar liquid became bright and clear, and the first bone char was introduced to the sugar industry. Later, it was discovered that the bone could be cleaned, burned, and ground into different sizes so when the sugar liquor was filtered through, the results were even better than when the powdered bone char was used. Imperial Sugar used the bone char method for de-colorizing the liquid sugar since beginning operations in the early 1900s.
The 1953 article stated “Exactly what mechanical or chemical transition occurs within the filters as the char and liquor are mixed has never been definitely established. It is known, however, that char has the inherent quality of absorbing color and various salts from the sugar liquor.”
When William T. Eldridge and Isaac H. (Ike) Kempner, Sr. acquired the bankrupt Cunningham refinery in 1908 and established the Imperial Sugar Company, an existing char house was part of the acquisition. In 1925, the $1M (over $17M in today’s dollars) addition of the eight-story Char House was completed.
The decolorization process in the Char House was basically a filtering process. The height of the building let the liquid sugar flow by gravity through the char, providing an efficient operation. The bright amber sugar liquor was pumped to the eighth floor of the Char House, to large storage tanks. From there, it was discharged into the top filters on the sixth floor by gravity. The liquor continued through the char, coming out at the bottom of the filters nearly “water white” and had an apparent purity of 99.7-percent.
Another advantage of using the gravity filtration system with bone char was the char could be re-used. The char acted like a sponge absorbing water. When a sponge remains in water, it gradually absorbs less and less water until completely saturated. When the char is “exhausted”, the char is washed in hot water to remove all traces of sugar, air dried, and then transferred to “revivifying” kilns. The brick kilns were heated to a “red-hot” heat using natural gas. The char would pass through retorts (pressure vessels) that extended through the furnaces. After all the impurities were burned from the char, it was cooled, screened, and then returned to the sixth floor.
Although from the outside the Char House appears to have been an office building, when it operated as part of the refinery process, the building contained steel containers stacked vertically. These containers contained the bone char used to decolorize the raw sugar. Once the sugar liquor was cleared in the Char House, it still needed to undergo evaporation, crystallization, and granulation, before being put into packages for retail and wholesale purchases. These operations were done in other areas of the refinery.