What every New York Pizzailo (pizza chef) will tell you is that the city’s water is one of the key factors that makes a New York pie so amazing. In whiskey production, quality water is just as important. As much as 60% of whiskey is water, and Master Distillers around the world go to great lengths to not only know what is in their water, but to make sure it is of the highest quality for whiskey making.
It is no accident that historic distilleries are almost always adjacent to healthy, reliable sources of water – an economic and logistical necessity in the days before city-run water distribution systems. Whiskey’s fate is inexorably intertwined with that of water, which is used throughout the whiskey production process. As much as whiskey-making is a business built on grain, it is also a business built on water.
How Water is Used in Distilling
From the beginning, as corn, rye, and barley are hauled to the distillery by rail and truck, water is used to wash away dirt and other containments from the raw grains. In Scotch production, water is used for malting barley — key to getting the barley to start its enzymatic reactions to start sprouting. During mashing, milled grain is added to water to produce wort for fermentation, and part of the “magic” of distillation is that water and alcohol have different boiling point, allowing the alcohol to vaporize and move up the still.
Water is also used to cool condenser pipes that change the distilled alcohol vapors back into liquid form, where they can be collected for further distillation or for barreling. Except in the case of barrel strength whiskey, water is added to whiskey being dumped from barrels to “proof down” the final product. This ensures the whiskey hits the distiller’s preferred ABV, which in itself is an expression of the volume of water to alcohol in whiskey. And after all the whiskey making components have left the mash tuns, fermentation vats, and stills, water is used to clean everything to exceptionally high standards to guarantee the integrity of future batches.
Picking up Minerals
When we turn on the tap, most of us don’t think much about the journey that water took to end up a the bottom of our glass. Rain water coming from the sky is essentially “soft,” with little to no mineral content. Water “hardens” as it journeys across the landscape gathering solubles and minerals, such as magnesium, calcium, potassium, sodium, and bicarbonate, from the ground, which change the flavor and consistency of the water that ultimately end up in a bottle of whiskey.
In Kentucky, for example, water flowing over and through porous limestone shelves in underground rivers, caverns, and aquifers absorbs trace amounts of magnesium and calcium carbonate. This limestone-enriched water is often described as having a “clean” or “crisp” taste, due to the balance of minerals. Moreover, these same limestone features filter out iron, which can cause whiskey to turn black as it ages in the barrel, and other impurities, and reduces the water’s acidity.
Similarly, in Scotland, water plays an important role in the creation of whiskey. Scottish water generally tends to be “soft,” meaning it has a lower mineral content, which leads to the mellowing of the whiskey during mashing and fermentation. Many areas of Scotland have granite as the bedrock, which is hard and less soluble than limestone. However, water sources in Scotland are varied and contribute to different flavor profiles as higher or lower mineral content can react differently with malted barley and yeast.
Purifying Water for Distillation
Regardless of where the water comes from, distilleries will conduct some level of cleaning process to remove unwanted elements that could contaminate the whiskey production process. Water can be distilled, or purified through filtration. Distillation, however, results in more neutral water characteristics due to the removal of minerals, which most whiskey distillers want to keep in; while filtration leaves in minerals that can help round out flavors.
Some common filtration methods are activated carbon filtration (passing water through activated carbon filters), sand or gravel filtration (passing water trough layers of sand or gravel), reverse osmosis (using semi-permeable membranes to remove solids), charcoal filtering (passing water through layers of charcoal), or micron filtration (passing water through fine filters with microscopic pores). Filtration techniques can be combined with one another depending on the desired characteristics and quality of the water.
The pH level of water can affect the enzymatic reactions during fermentation. Water that is too acidic can impact yeast activity, which can lead to sluggish or stalled fermentation. Acidic water can also impart a sharp or sour taste to the whiskey, and mask desirable flavors created during the aging process, and interact with chemical compounds in the whiskey or potential influence the interaction between the whiskey and the wood barrel.
Sustainable Use
As eco-systems change around the globe, whiskey is not immune to the environmental risks more broadly impacting water. Rising temperatures, altered precipitation patterns, and increased water scarcity will inevitably begin to affect the availability and quality of water in some whiskey producing areas, and make it harder to secure necessary water resources. Moreover, chemical contaminants can find their way into water sources used for whiskey production, which can compromise the purity of the final product.
The 1996 Heaven Hill and 2019 Jim Beam rickhouse fires, in Bardstown and Versailles respectively, caused environmental catastrophes. Leaking alcohol from these fires flooded into local water sources, the later generating a 23-mile long plume of whiskey in the Kentucky and Ohio Rivers that killed untold numbers of fish and wildlife, and which travelled as far as Indiana. Water contaminated with whiskey, ironically, is not necessarily good for making more whiskey!
Many distilleries, whether because they believe in it, see it as a good marketing opportunity, or forced by local environmental factors or regulatory issues, are moving toward sustainable use of water in their production of whiskey. That often means implementing closed-loop water systems where water can be reused in different stages of production, thus saving money and lowering their impact on watersheds. Distilleries are also actively working with local communities who have a stake in protecting local ecology and water quality to strengthen the health of local waterways.
While a distillery no longer needs to be next to a large river to access clean water, thanks to the miracle of modern technology, regional water sources will still play an integral role int he production of whiskey, providing one aspect of a whiskey’s provenance. Colorado whiskies will continue to boast about their access to clean, crips water from Rocky Mountains; Pacific Northwest about their glacial-fed rivers and lakes; and Kentucky, as it has for the the past two centuries, about its limestone purified springs and aquifers. And the whiskey is better for it.
