Water in whiskey production
Water quality plays a big part in distilled spirits. Without a proper filtration process, you could be introducing unwanted minerals and bacteria into the final product, which can change the flavor, odor, and color of your whiskey. When it comes to whiskey, we often associate water with the process of dilution of the final product, but water is present throughout the entire production.
Malting the grain. Any cereal grain can be converted to malt, but barley is most frequently used. The first step will be to soak the barley in water. It’s then spread out and sprinkled with more water for three weeks until it sprouts. The next step involves drying the barley. This sometimes involves a kiln or peat which can give Scotch whiskey a characteristic smoky flavor.
PS: It’s important to understand the germination of the grain as it produces enzymes responsible for converting barley into sugars. However, for the production of American whiskey, malted grains are often imported; as a result, they skip this step and go directly to the milling and cooking of the grains.
Cooking. Ground grains are cooked up to four times in hot water, depending on the type of cooker and grain. This pot is filled with hot water and cereals, which are then cooked until they have rich the gelatinization point (Oats: 53-59°C Wheat: 58-64°C Rye: 57-70°C Corn: 62-74°C), which allows enzymes to enter and break down starches into sugars.
PS: In other types of whiskey production, such as Scotch, Irish, and Japanese, the cooker is replaced by a mash tun in a process called Mashing. In this, cooked grain is mixed with malted barley and warm water. Amylase, an enzyme found in malted barley, converts starch into sugar. The result is a thick, sugar-rich liquid called mash.
Fermentation. Fermentation is the process of converting sugar into alcohol, as well as the different techniques for whisky production, including sweet and sour mashes. After the mash has cooled, it is diluted with more water and transferred to large tanks for fermentation. By adding yeast to the mixture, the sugars present are converted into alcohol. As a result, the liquid will have an alcohol by volume of between 5% and 10%.
Distillation. A substantial amount of water is used during distillation to condense vapors of alcohol through tubes and cooling systems. 95% of water is used during condensing and cooling.
Aging. Water covers even a safety role when it comes to barrel aging, it is important to have a large water source between the warehouse in case of fire… without even mentioning cleaning the plant.]. Alcohol is a natural solvent. The greater the concentration, the greater the extraction of flavor. That's why by law American whiskey cannot enter the barrel at more than 62.5%ABV. The quality of water used to bring down the barrel entry proof is as significant as the quality of the spirit itself.
Bottling. Depending on which part of the world, whiskey has a minimum bottle proof. In the US, it is 40%. Although some distilleries bottle their whiskey undiluted, most of the whiskeys exported internationally are around 40%ABV. This last dilution is so critical to the quality of the product that unless it is done in the country of production the only water allowed for this final step would be pure or distilled water.
Soft and Hard water
As an example, let’s look at Scottish water.
There’s a belief that harder waters produce sweeter and lighter spirits in Islay, the Highlands, and to a lesser extent the Lowlands. Others say hard water contains minerals that add spiciness to whiskey. The presence of minerals such as zinc, calcium, and magnesium is indeed essential for a good fermentation, but most of these elements are already in the grains themselves.
Another example is when microbes in the water work on grain and yeast to lower alcohol production and enhance flavor. Soft water, which has more organic matter, like peat phenols, and fewer minerals, produces more esters during fermentation, which gives the whisky a fruity taste.
Since soft water has a lower pH, some distilleries say it’s a better solvent and can extract a lot more from the grain during mashing or cooking. There has been a long-standing claim that Scotch whiskey is better when it is made with soft water, water with a lower pH level. In the past, water would rise through peat and eater and run over granite or concrete, but that has changed over the years, increasing the acidity. Besides granite being so hard, it imparts no minerals to the water running over it, and most distilleries use water pumped from wells and streams before it gets to contact with peat, without mentioning filtration such as a reverse osmosis or UV light system.
PH in water
The most suitable water for whiskey production is between 7 and 8 pH. That's because water with a pH above 8.5 is considered basic and creates an ideal environment for bacteria. Water with a pH lower than 6.5 is considered acidic, which is what we want in fermentation, ideally around 5.5.
Reverse osmosis can remove calcium and minerals from hard water, bringing down its pH level. High levels of calcium carbonate prevent yeast from interacting with sugars in the mash and can spoil the entire fermentation process.
If we don't use the right water throughout all processes we can ruin the distillery equipment and more importantly create inconsistency and undesirable substances in our product. Like the “floc”.
Oxalic acid (Oxalic acid is often found in vegetables and it's harmless in small amounts) is a chemical produced during mashing and fermentation. Oxalic acid reacts with calcium to form Calcium Oxalate, also known as "Floc", a viscous substance not soluble in alcohol. For this reason, most distilleries use reverse osmosis to remove calcium from locally sourced water.
What is the best water for you?
Would you go for Hard water with a lower pH, and a sweeter, lighter flavor?
Or for Soft water with higher pH, more minerals, and a spicier, fruity flavor?
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