The environmental impact of distillation is multifaceted, occurring in all stages of spirits production, from raw material growth and extraction through processing, manufacture, distribution, and disposal.
Raw Materials
Distilled spirits are produced from various agricultural products grown all over the world, in diverse conditions with widely varying attention to the environmental impact of the agricultural practices employed. When improperly managed, activities from working farms can negatively affect water quality through sediment and nutrient pollution, air quality through burning or poor management of byproducts, and biodiversity through the increased use of genetically uniform varieties.
According the US Environmental Protection Agency, nutrient pollution is one of America’s most widespread, costly, and challenging environmental problems. In the 2000 National Water Quality Inventory, states reported that agricultural nonpoint source (NPS) pollution was the leading source of water-quality impacts on surveyed rivers and lakes, the second largest source of impairments to wetlands, and a major contributor to contamination of surveyed estuaries and groundwater. Agricultural activities that cause NPS pollution include plowing too often or at the wrong time, as well as improper, excessive, or poorly timed application of pesticides, irrigation water, and fertilizer.
The Food and Agriculture Organization of the United Nations has reported that since the 1900s, some 75 percent of genetic diversity has been lost in agricultural crops as farmers worldwide have replaced local varieties with genetically uniform, high-yielding ones. The Harvard School of Public Health has stated that protecting biodiversity in the ecosystems that support food production and fresh water and preserving genetic diversity in our crops are both critical to ensuring our ability to produce food with ever-shrinking terrestrial and aquatic resources. Corn, one of the most common grains used to make spirits, is particularly susceptible to this type of pressure due to the size and competitive nature of its market. See corn. Agave, with its lengthy maturation period, is also vulnerable to a loss of genetic diversity. See agave.
Raw-material processing and handling present additional potential for environmental impact. Dust from the processing of grain and sugar (including field burns common in the sugar-cane industry) impact air quality and present a hazard to worker safety. See sugar and sugar cane. According to the US Occupational Safety and Health Administration, the grain-handling industry is a high-hazard industry where workers can be exposed to numerous serious and life threatening hazards. These hazards include fires and explosions from grain dust accumulation, suffocation from engulfment and entrapment in grain bins, falls from heights, and crushing injuries and amputations from grain handling equipment. In 2010, fifty-one workers in the United States were engulfed by grain stored in bins, and twenty-six died—the highest number on record.
The agricultural products used to produce the vast majority of distilled spirits (grain, sugar cane, agave, and fruit) are all subject to these issues in varying degrees. The larger the scale of the distilling operation, the greater the complexity of the supply chain and the more challenging it is to ensure that all suppliers are employing responsible practices. These concerns can be mitigated through the thoughtful, direct selection of farming partners employing sustainable practices.
Spirits Production
The production of distilled spirits is an energy-intensive process, requiring the precise heating and cooling of large amounts of water and alcohol throughout the process.
The most prevalent sources of energy used for this are carbon-based fuels, either burned in a boiler at the distillery to produce the steam that is used for heating or consumed in the form of electricity, most commonly generated from coal or natural gas, to run compressors that drive the cooling process. Depending on the distilleries’ location and available resources, other sources of heating and cooling energy may be available.
Large-scale rum production facilities are often able to integrate sugar-cane processing into the spirits production facilities and use the bagasse (the fibrous part of the sugar cane that remains behind after the cane juice is extracted) to generate high-quality heat and power on site. Agave bagasse may also be used in this way, although it is not yet common practice.
Some distilleries have opted to develop and utilize technology to make their distilleries more energy efficient, reducing the overall need for energy to produce the spirits and lowering the carbon usage per bottle of spirit produced. The scotch whisky industry in particular, driven partially by strong government incentives in the form of taxes and grants, strong financial incentives in the form of expensive fuel costs, and a prevailing sense of responsibility to the land, has invested many resources in developing, testing, and implementing innovative strategies to improve their efficiency, such as mechanical or thermal vapor recompression (MVR/TVR), an advanced method of recovering energy from the distillate. See whisky, scotch.
The push to improve energy efficiency can be more powerful for larger producers, where small gains in efficiency can lead to significant financial gains due to the scale of their processes. For small distilleries, although the financial incentives may be less, the smaller scale of the demands and the increased process flexibility can lower the barrier for implementing more creative or innovative efficiencies.
Byproducts of Spirits Production
Spirits production generates many byproducts: spent grain, fruit fibers or pits, pot ale, solvents, carbon dioxide, and others. These byproducts are unavoidable, inherent to the spirits production process, and have the potential to cause significant environmental harm when handled irresponsibly. However, many can find a useful life in other industries when handled conscientiously.
For example, carbon dioxide is a byproduct of all alcohol fermentation. See fermentation. For every pound of ethanol produced for our drinking pleasure, approximately 9/10 of a pound of carbon dioxide is generated by the yeast. Carbon dioxide (from many different sources) is a major culprit in driving global warming. Some large-scale spirits producers capture, compress, and sell the carbon dioxide generated in their fermentation tanks, thus preventing it from being released into the atmosphere and providing beneficial use for other applications, such as beverage carbonation. See carbonation. While carbon dioxide release is certainly undesirable, alcohol fermentation is not a major global contributor of greenhouse gas emissions. The liquid and solid byproducts of spirits production, left behind after mashing and/or distillation in the form of spent wash, spent grain, or spent mash, are often of more immediate concern. See mash.
The production of malt whisky generates approximately 17.5–20 pounds of spent grain per gallon of proof spirit and 4.5–6 gallons of pot ale per gallon of proof spirit. Grain whisky production is more efficient, with 5–6.5 pounds of spent grain produced per gallon proof spirit and 9–12 gallons of spent wash. See whisky, grain. Bourbon and rye whisky production resides in between the two, but the spent grain and pot ale are generally combined in one byproduct stream, called the “spent mash.” See whisky, bourbon and whisky, rye. Rum and tequila generate 1.5–2 gallons of spent wash per gallon of absolute alcohol. See rum and tequila. These byproducts have very high pollution values with a very high biochemical oxygen demand if untreated.
Biochemical oxygen demand (BOD) measures the amount of oxygen required or consumed for the microbiological decomposition (oxidation) of organic material in water. See oxidation. The release of products with high BOD into existing waterways poses a potential threat to a variety of aquatic organisms by stimulating algae growth, which uses up the oxygen in the water and essentially suffocates the other aquatic creatures. Severe algal growth also blocks light that is needed for water plants to grow. When the algae and seagrass die, they decay. In the process of decay, more oxygen in the water is used up, and this, in turn, can continue to kill fish, crabs, oysters, and other aquatic animals. Algal growth also makes water unsuitable for human consumption or for use in agriculture. According to the US EPA, this type of pollution is one of America’s most widespread, costly, and challenging environmental problems.
Pot ale will typically have 25,000–35,000 ppm BOD out of the still, and spent lees 1,000–2,000 ppm BOD. These byproducts can be reused as high-value animal feed. Depending on the scale of the operation, additional treatment (such as drying) may be necessary to preserve the animal feed for distribution. This has the benefit of keeping the byproducts out of the watersheds, but the processing requires additional energy. The byproducts can also be treated on site to reduce the BOD via the use of digesters, which are effective and have the added benefit of producing methane that can potentially be used as a supplementary boiler fuel, but they are costly to install and require skilled operators. The draff (solids) can also be burned directly, but with a relatively low efficiency and a high particulate emission.
As long as producers are attentive to the environmental risks posed by these byproducts, the threat to the surrounding environment can be minimized. The problems result from inattentive or unconcerned producers with frequent leaks, spills, or intentional releases. Developing nations with lax environmental regulations or limited enforcement capabilities are particularly vulnerable to these types of abuses and often lack the infrastructure to collect or treat this type of emission.
Global Shipping
The rich sensory experience of a bar offering spirits from every corner of the globe is not without consequences. From the farmer’s field to a consumer’s glass there are many miles of travel required, each mile with an environmental cost. Common environmental impacts of the global shipping industry include the release of oil and chemicals through accidental spills and operational discharges, the transfer of invasive alien species through ballast water and on ship hulls, dumping of garbage and sewage, and air pollution through emissions of sulfur dioxide, nitrogen oxides, and carbon dioxide.
In the United States alone, the transportation industry releases several million tons of gases each year into the atmosphere, containing lead, carbon monoxide, carbon dioxide, methane, nitrogen oxides, and particulate matter. Better engine technology and stringent standards enforced in developed nations have reduced the amount of pollutants released substantially over the last thirty years, but the transportation industry remains one of the largest contributors of greenhouse gas worldwide. The lack of a global framework for addressing the environmental impacts of international shipping and difficulties in monitoring and enforcing presents significant challenges to curbing these impacts.
While many producers are making an effort to prioritize local sourcing of raw materials to significantly reduce their footprint, the loss of local sources for manufactured products like glass bottles presents a serious challenge in this regard. Trends in the spirits industry toward an increasingly global marketplace featuring heavy and irregularly shaped bottles exacerbates this problem.
Packaging
The choice of packaging in which spirits are distributed and marketed to the consumer presents another opportunity for producers to consider the environmental impact of their products. Spirits are most commonly packaged in glass bottles. Glass manufacture is an energy-intensive process, requiring high temperatures reached through the combustion of fuel with its resulting emissions. Glass is a commonly recycled material, although detailed life-cycle analyses on recycled goods have illuminated the complexity of these benefits. When compared with the amount of energy required to send the same goods to landfills or incinerators and make new products from scratch, the results vary dramatically, but recycled glass generally uses about 20 percent less energy to produce than virgin glass. Minimizing the amount of glass per package (thinner bottoms, efficient shaping) reduces the resultant emissions from both the manufacture and shipping of the glass. See glassware.
Choosing minimally processed, recycled paper labels and water- or vegetable-based inks with no VOC adhesives is another way a spirits producer can minimize the environmental impact of their packaging. Other types of labels, such as transfer labels and screen-printing, utilize potentially hazardous solvents and require additional energy to execute. Closures are yet another opportunity for producers to make environmentally responsible choices. Independent studies have indicated that the use of natural cork stoppers, as compared to aluminum or plastic, can have a strong beneficial impact.
Water
It is no coincidence that distilleries have historically been located in areas with abundant natural water supplies. It takes more than 30 gallons of water to produce one gallon of finished spirit. In regions with copious natural water supplies there is minimal appreciable impact of a distillery’s usage, but the expansion of distilleries into areas with low or unpredictable water supplies can strain already taxed water systems. This impact can be reduced by implementing closed cooling systems that continuously recycle cooling water, although there is a price to be paid in electrical usage for such a system. In a world of increasingly extreme, unpredictable weather and drought events, attention must be paid to conservation in many parts of the world.
“Agriculture.” Water.epa.gov. http://water.epa.gov/polwaste/nps/agriculture.cfm (accessed October 19, 2015).
“Agriculture Facts.” Water.epa.gov. http://water.epa.gov/polwaste/nps/agriculture_facts.cfm (accessed October 19, 2015).
“Biochemical Oxygen Demand in Water Bodies.” UN.org. http://www.un.org/esa/sustdev/natlinfo/indicators/methodologysheets/freshwater/biochemicaloxygen_demand.pdf (accessed March 3, 2021).
“Biodiversity and Agriculture.” Chgehavard.org. http://www.chgeharvard.org/topic/biodiversity-and-agriculture (accessed November 6, 2015).
“Common Impacts of the Shipping Industry.” WWF website. http://www.wwf.org.au/ourwork/savingthenaturalworld/oceansandmarine/marinethreats/commercialshipping/impacts/ (accessed October 25, 2015).
Jain, Radha, and S. Srivastava. “Nutrient Composition of Spent Wash and Its Impact on Sugarcane Growth and Biochemical Attributes.” Physiology and Molecular Biology of Plants 18, no. 1 (2012): 95–99.
“Nitrogen and Phosphorus.” Cbf.org. http://www.cbf.org/about-the-bay/issues/dead-zones/nitrogen-phosphorus (accessed October 12, 2015).
“Nutrient Pollution: The Issue.” EPA. http://www2.epa.gov/nutrientpollution/problem (accessed March 3, 2021).
OECD. Environmental Impacts of International Shipping: The Role of Ports. Paris: OECD, 2011.
Oñiguez, C. G., C. J. J. Bernal, M. W. Ramírez, and N. J. Villalvazo. “Recycling Agave Bagasse of the Tequila Industry.” Advances in Chemical Engineering and Science 4 (2014): 135–142.
Piggott, J. R. The Science and Technology of Whiskies. Harlow, UK: Longman Scientific & Technical, 1989.
Russell, Inge. Whisky Technology, Production and Marketing. Amsterdam: Academic Press, 2003.
“What Is Nutrient Pollution?” NOAA.gov. http://oceanservice.noaa.gov/facts/nutpollution.html (accessed March 3, 2021).
By: Nicole Austin