Estimating Production of Brewery and Distillery Spent Grains in Tennessee and Identifying Sustainable Uses

Brewery and distillery spent grains (BDSG) are a by-product of the fermentation process and consists of various grains, hops, and flavor additives. Large breweries and distilleries can establish and maintain marketing channels to dispose of BDSG typically as a livestock feed. However, small-scale businesses may lack the necessary resources and contacts to dispose of BDSG, thus creating the potential disposal of BDSG through a landfill or wastewater system. This study aims to estimate the production of BDSG by craft breweries and distilleries in the state of Tennessee and identify sustainable uses and marketing channels for the product, which includes use as animal feeds and composts, soil amendments, or fertilizers for traditional agriculture and urban agriculture.The objectives of the study are: i) determine the quantity of BDSG being produced in Tennessee by craft breweries and distilleries; ii) determine current BDSG disposal practices; and iii) determine the cost-savings for farmers resulting from BDSG disposal by breweries and distilleries as a livestock feed. These objectives were accomplished by surveying craft breweries and distilleries in Tennessee regarding their production practices and developing a linear programming model to determine the value of BDSG as a livestock feed for beef cattle.Results of the survey indicate that the majority of breweries and distilleries are disposing of their spent grains as a livestock feed, with 100 percent of breweries and 87 percent of distilleries indicating that they dispose of at least a portion of their spent grains in this manner. Conversely, few breweries and distilleries are disposing of their spent grains as a compost, soil amendment, or fertilizer with only 15 percent of breweries and eight percent of distilleries selecting this method of disposal. Average annual production of BSG and DSG per brewery and distillery in the survey was 65,800 pounds and 51,808 gallons. Results of the least-cost winter feed ration suggest that significant cost savings can be afforded to farmers by including spent grains at their average daily production rate of 7.2 pounds of BSG and 47.1 pounds of DSG.