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Maintaining constant fermentation conditions with variable sources of sugar cane molasses |
H. HUERTAS and R. J. SERRALLÉS. Destilería Serrallés Inc., Main Rd. #1, PO Box 198, Mercedita, PR 00715-0198 The last decade has witnessed a sharp decline in the quality of sugar cane molasses. The quality of sugar cane molasses dramatically affects the behavior of yeast cells during alcoholic fermentation. The key parameters that determine the quality and fermentation potential of sugar cane molasses are sugar content, minerals, suspended solids and acidity. The concentration of sugars during the fermentation must be controlled in order to prevent osmotic pressure or long fermentations. High concentrations of calcium and chlorides negatively affect the alcoholic fermentations of cane sugar molasses, while minerals like magnesium and zinc exert a positive effect on yeast health and productivity. Sugar cane molasses are normally pasteurized or decontaminated in order to reduce the amount of microorganisms acquired during its production, transportation or storage. Usually, heating the molasses above 170°F reduces the number of wild yeast and lactic bacteria but also decreases viscosity and precipitates calcium. High concentration of suspended solids also makes pasteurization inefficient and thus the use of antibiotics or a very high count of yeast cells are needed to overcome the bacteria that the suspended solids hide. The acidity of sugar cane molasses varies depending on the harvesting techniques. Very high acidity content on cane sugar molasses is detrimental to yeast fermentation. Finally, the quality of sugar cane molasses varies depending on its geographical origin and on the time of harvest. Furthermore, the availability of good quality molasses depends on the efficiencies of the specific sugar refineries, on weather conditions and on harvesting techniques. Unfortunately, these variables lead to an inconsistent supply of good quality sugar cane molasses and a constant dilemma for sugar cane molasses distillers.
Session 94, Challenges of converting carbohydrates into flavors by fermentation
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