The Best Water For Making Whiskey (And How To Treat It!)

Image of diy distilling the best water for distilling and making whiskey

Water is by far the biggest component in whiskey making. From the steeping and mashing of the grains, right through to diluting (proofing) the final spirit.

And when an ingredient is so important, we need to make sure we use the right type of water!

Felipe Schrieberg points out that  “while whisky nuts obsess over every tiny detail of the production of their favorite drum, they typically devote very little attention to the water they add to it. That’s a big mistake.” 

This article will inform you about the best water for making whiskey and how to treat the water in producing the most delicate whiskey taste.  

Why Listen To Us? Our team of writers have more than 16 years of distilling experience between them. We've written These Books, designed the perfect Hobby Still, and have helped over 100+ amature distillers through our Ask The Expert portal. 

How is water used in the whiskey-making process?

Experts indicate that the required criteria to perform distillery production is a plentiful, wholesome supply of clean and clear water. The distribution of water throughout various stages of whiskey-making is the major part of distillery production. Palmer and Kaminski (2013) agree with Dolan (2003) that water is necessary at various stages in the production process in both distilling and brewing. 

Water for making whiskey is added during malting and mashing and removed during distillation and coproduct treatment.  Water is later added during the maturation stage. 

An interesting fact shared by Dolan is that it is relatively cheap to add cold water for making whiskey but expensive to remove the water. 

Different process requirements will determine the source of the water and the quality of water for making whiskey. Generally, a distillery requires more than one different way of access to the water source. 

Broadly, water usage in a whiskey-making distillery falls into three main categories. 

  • Water is used during the distillery process itself.
  • Cooling water, which is used in fermenters and condensers during distillation.
  • Ancillary and service supplies (which are used to supply the boiler house and heat recovery systems, as well as to fulfill other site requirements. 
Image of diy distilling the best water for distilling and making whiskey 2 1. Jpg 1

Is All Water The Same?

Not all water is the same for making whiskey. In Scotland, normally malt distillers use soft water with a lower pH level, as this becomes favorable and beneficial to the yeast

However, in other locations, hard water is used for making whiskey as local availability and geology determine the quality of the water.

For instance, American distillers of Bourbon and some Canadian distillers glorify the desirable quality of their hand limestone water and its positive effect on the process of producing certain congeners.

To overpower the pH alkalinity level of limestone water, a sour mash process is often targeted with thin stillage added to produce acidity to the mash. 

How Can Water Affect The Process Of Making Whiskey?

Tracing down tradition, malt distillers would not generally usually use any water treatments, as doing so might affect the flavor characteristics of the wort and the spirit. However, processed water is often considered to make a major contribution to the quality of spirit. 

Therefore, it is important to know the right source of processed water to choose from, as the salt present in processed water can affect the pH level. This can influence the efficiency of the malt enzymes and provides essential trace elements for yeasts to maintain good fermentation performance. 

A useful guide to selecting the right sources of processed water is to read the ingredients of the components of the water or get it tested. Calcium, magnesium, and zinc are all essential ions for yeast. Calcium is also an important co-factor for the activation of starch-degrading enzymes. 

Excessive levels of sulfates can result in reduced pH levels in the mash. This leads to a negative impact on the mashing process and eventually the fermentation performance.

High levels of carbonates present in the mash can increase pH levels and will increase the risk of scale formation on heating surfaces. 

Surface water with a high concentration of nitrates or sewage pollution should be avoided at all costs.

Components Concentration (mg/L)
Total Dissolved solids 46
Calcium 5
Magnesium 6
Bicarbonate 5

How To Treat The Mash Water For Making Whiskey

To properly conduct water treatment for brewing and distillation, all unnecessary pollutants must be removed. The most effective method for removing the largest impurities in the water is the reverse osmosis system. 

Chlorine and other organic compounds such as iron, manganese, or sulfur are removed by the process of backwashing the carbon filter before the reverse osmosis system. 

If the water is over 4 or 5 grains hard (over 70mg/1 hardness), then a water softener or antiscalant must be added. One must proceed to the reverse osmosis system.  

After the water is processed through the reverse osmosis system. The water is stored in an atmospheric storage tank, which is from 100 gallons moving up to 2000 gallons in capacity. 

Some distillers opt to put the water from the reverse osmosis system through the demonization (DI) system, which results in absolutely pure water sitting at a pH level of 7.0.

After the water is placed in the storage tank, there is a re-pressurization pump that delivers the water to the desired sources at approximately 60PSI up to 22GPM.

To prevent any airborne bacterial contamination, there is an ultraviolet (UV) light in line to destroy any bacteria formation. 

Why Do You Need To Perform Water Treatment? 

The main purpose of water treatment is to remove any unwanted components from the water before its use in the mashing process. In other circumstances, where legally approved, water treatment is undertaken to add desirable components missing from the water. 

How To Filter Your Water For Cutting/Proofing Whiskey

1. Reverso Osmosis

Reverse osmosis is one of the filtering methods used to purify water. Therefore, reverse osmosis is practiced by applying pressure to forcibly flow through a semipermeable membrane. 

Reverse Osmosis takes place in different stages. 

  • Prefiltration stage- This is when water first enters the reverse osmosis membrane, and prefiltration takes place. This is when carbon filters and sediment filters start removing chlorine and sediments that could damage the filtration process and the reverse osmosis membrane. 
  • Next, when the water is purified from toxins, then reverse osmosis takes place and every dissolved particle, even the tiniest to be identified by a digital microscope, is damaged. 
  • After the filtration process, water flows to the storage tank, where it is stored until it is needed. The reverse osmosis system continues to produce filtered water that is stored in the storage tank until full. 
  • Postfilter stage- This is when you turn on your drinking water faucet and the water is polished to serve fresh pure water. 

2. Filtration

Filtration is considered to be an effective method to purify water by adopting both chemical and physical processes to clear water from contamination. This simple filtration process allows the filter to eliminate both large and small pollution components that can cause disease. Therefore, compared to reverse osmosis, filtration is considered effective when it comes to the selective elimination of much smaller molecular compounds such as chlorine and pesticides. Water that has undergone filtration is considered to be much healthier than water purified by other methods. The reason is that the filtration process does not destroy all mineral salt from the water. This process is considered effective, as it is less expensive compared to distillation and reverse osmosis. 

3. Deionization

(coming soon)

4. Iodine Method

When using the iodine method to purify your water, make sure to have common household iodine or tincture of iodine with you. Add 2% tincture of iodine drops to every liter of water you want to purify. If the water does not have a clear appearance and is cloudy, add 10 (ten) drops of iodine into the water and stir. Let the water sit for 30 minutes before using it as that key element in your whiskey. 

Don’t dwell too much on the thought of adding water when serving your whiskey. Rather, get up and make the finest whiskey tasting by adding that purified water to the mix. 

A DIY Water Filtration System:

Looking to build a filtration system yourself?

  • Boiling water for one minute makes it safe to drink. However, if you are at an elevation of 6,500 feet (1,981 meters), then boil the water for three minutes. 
  • Add tablets that purify the water, such as chlorine dioxide, sodium dichloroisocyanurate, tetraglycine hydroperiodide, and iodine. Let them sink and sit for a directed set of time.
  • Allow the water to be directed by the ultraviolet light from the sunlight. This process damages any bacteria in the water. Therefore, disinfection of the water is accomplished. 
  • Proceed to activate charcoal. Charcoal adsorbs toxic compounds, smells, and germs. It can also reduce heavy metals and fluoride. (To use it, simply pour charcoal into a sock or a clean cloth bag and pour water inside.

However, there are sediment travel filters designed by companies, such as hand pump machines,  filtering straws or bottles, and filtering pitchers to make the experience easier.


  4. Tom A. Bringhurst, Barry M. Harrison, James Brosnan, Chapter 11 – Water: An essential raw material for whisk(e)y production,

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