YOU PUT YOUR HEART AND SOUL INTO THE BOTTLE ...DRESS IT ACCORDINGLY
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spirit composition. This all seems virtuous and straight-forward, but there are some additional details that need to be considered. The whey itself needs to be pasteurized and perhaps stored sterile until ready for use. For a creamery producing cheese on a daily basis, it would be prudent to couple distilling and whey production schedules to minimize the risk of infections developing. Scaling of the distilling operation to match creamery capacity is essential in this respect. A notable infection challenge is from lactic acid bacteria, which can produce diacetyl in flavor-active quantities but which, unfortunately, essentially co-distills with ethanol, making it difficult to remove once it has been formed. Another hurdle is the by-product stream. Ten pounds of milk yields around one pound cheese and nine pounds whey. After fermenting and distillation, the remaining aqueous by-product stream in the still is still more than seven pounds (Fig. 1). There are some points to note here. Firstly, converting lactose quantitatively into ethanol by fermentation substantially reduces BOD, so fermentation then disposal without recourse to further processing steps is not without merit in this context. Secondly the “dilute alcohol stream” (Fig. 1) could, if sufficiently good quality, be formulated into cocktail-type products, although an additional step, such as using membranes to concentrate alcohol, would be required. If the cocktail route was selected, sugar supplementation prior to fermentation is likely to be a simpler strategy, given that ethanol contents of at least 10% (v/v) would be required before cutting with flavors, colors and mixers to create final products. As a final point, we should consider how whey alcohol might affect the value chain from milk. As mentioned, ten pounds of milk will yield around one pound of cheese, let’s say at $40/lb retail. The resulting nine pounds of whey typically contain around 0.45 lb (205 g) lactose. Fermentation results in around half of the mass of sugars lost as carbon dioxide, so approximately 100 g (125 ml) of alcohol will be produced in a well-run operation. For argument’s sake, we can assume this is enough ethanol for a third of a 750 ml bottle, so perhaps $12 in retail. While these figures are clearly back-of-the-envelope estimates and does not include cost of production or taxes or any effluent savings, there remains REFERENCE good potential for smallRisner, D., Tomasino, E., er creameries to offset Hughes, P. and MeunierGoddik, L., Volatile aroma effluent costs, enhance composition of distillates sustainability credentials, produced from fermented sweet and expand product portand acid whey, Journal of Dairy Science, 2019, 102, 202-210. folio by investing in alternative whey processing technology.
Paul Hughes, Ph.D. is assistant professor of food science and technology at Oregon State University in Corvallis, OR. For more information visit www.oregonstate.edu or call (541) 737-4595. WWW.ARTISANSPIRITMAG.COM
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