homebrewing water

Choosing Water for Brewing Beer: A Very Important Guide

Even though I’ve heard beers negatively compared to water, even the highest quality craft beer is over 95% water. While other ingredients may have the reputation of giving beer its flavor, such as the grains, hops, or yeast, water may be, hands down, the most important ingredient. What type of water should you use to brew your beer?

Brewers should use a water source that has acceptable levels of minerals and trace elements, but does not have significant amounts of chemical additives or high acidity. If your home water source isn’t suitable, there are various methods to correct your brewing water. 

I’ll explain more about different types of water sources and common contaminants, what impacts they could have on your brew, and what you can do if you need to make adjustments to your brewing water.


What’s in Your Water?

A majority of homebrewers will use water straight from the tap.

Tap water is the easiest source of water to use for brewing.

If you commonly drink tap water from home, then you might not have a second thought about using it to brew.

Most people do not know that there are various chemical additives, water treatment, minerals, and other trace elements in the tap water that might vary based on water utility or even by season.

Some of the elements in water could impact the quality of your beer, some elements for the better, some for the worse.

So, what is actually in your water?


Water Basics

Even though water is a basic necessity of life, there are a lot of qualities and descriptions of various forms of water that can be a bit overwhelming. Every brewer needs to understand three components: pH, hardness, and alkalinity.


What is pH?

pH is a measurement of how acidic or alkaline a substance is, rated on a scale from 1 to 14, where 1 is the most acidic and 14 is the most alkaline.

A value of around 7 is considered to be neutral, neither acidic or alkaline.

The more acidic the liquid, such as water, is, the more hydrogen ions are present.

Against logic, a pH of 14 as the LEAST amount of hydrogen ions, while a pH of 1 has the MOST.

Deionized water is a reference to the removal of hydrogen ions in water, making the water more alkaline.

Many health and wellness theorists believe that alkaline water can reduce acidity in the body.

Healthline.com notes that alkaline water can be purchased from many stores or even made with water ionizers, but warns that drinking too much or too alkaline water can be dangerous.

On the opposite end of the pH spectrum, acidic water is more likely to be polluted with other contaminants and likely more unsafe to drink.

Tap water should have a pH of about 7.5, whereas common bottled waters range from 6.5-7.5.

Acid rain, for example, has a pH of 5 or less.

Ocean water, depending on the location, season, or even tide, as a pH of about 8.

The pH of your tap water can be easily tested with pH testing strips found online.

water ph


Hard Water

Hard water comes from magnesium and calcium dissolved in the water.

You can sometimes tell when you have hard water if you find mineral deposits around your faucets, sinks, showers, and bathtubs.

The term hardness comes from describing the ability for soap to lather.

Hard water requires more work to lather, whereas “soft” water is easier to lather.

Hard water can also be temporary or permanent.

Temporary hardness is a result of having high levels of carbonate while permanent hardness is a result of noncarbonate. Carbonate is a salt of carbonic acid, noted by the presence of the carbonate ion.

Carbonate minerals have many different common forms, such as baking soda, potash, limestone, coral, and chalk.


Understanding Alkalinity

The alkalinity of water can convey the water’s capacity to prevent changes in pH by maintaining a consistent concentration of hydrogen and hydroxide ions, otherwise known as a buffer.

Bicarbonate in water is a substantial buffer and is even present in the body to increase or reduce the human body’s acid levels.

As you add components, such as hops, yeast, or grains/malts, into your mash or wort, the pH, acidity, or alkalinity may change. The properties of the water can change how these components may taste in the finished beer.


Types of Water Sources

water bottles

Some may argue that water is just water.

However, just browsing the stores of a grocery store reveals many different types of bottled water.

So, what’s the difference between them all?

Bottled Water: The FDA regulates the contaminants that are allowed in bottled water. They define bottled water as “water that is intended for human consumption and that is sealed in bottles or other containers with no added ingredients except that it may optionally contain safe and suitable antimicrobial agents.”

Distilled Water: Distilled water is produced through a process called distillation. Distillation includes boiling the water until it vaporizes it, then collecting the condensation back into liquid into a separate container. Distillation generally produces a pure source of water, stripped of most minerals, chemicals, or other elements.

Mineral Water: Mineral water is water that has been bottled from a particular source where the mineral content and content of trace elements is consistent. Mineral water should not contain any more than 250 ppm (parts per million) of total dissolved solids (TDS). The source must be geographically and physically separated from other sources. No minerals may be added to the source water.

Well Water: Well water comes from a borehole that draws water from the aquifer. In order to draw water from a private well, the owner should have water quality testing conducted on the water drawn from the aquifer to make sure that it is safe to drink. However, well water often varies dramatically with the content of minerals, trace elements, as well as organic and inorganic contaminants.

Alkaline Water: Alkaline water is water that has been ionized, increasing the pH level. Normal tap water typically has a pH level of about 7, while alkaline water is around 8-9. Water can become alkaline naturally from contact with rocks and minerals in the ground. Too high of alkalinity can be unsafe to drink.

Hard Water: Hard water has a high concentration of minerals, typically magnesium and calcium, though other minerals can cause hard water as well. Some groundwater sources and aquifers naturally have harder water than other sources.

Purified Water: Purified water may have been treated with a process such as distillation, deionization, or reverse osmosis to remove high concentration of undesirable contaminants. Purified water usually comes from a groundwater or spring source that many not meet the requirements for drinking water without some treatment.


Minerals and Elements

In a sampling of water throughout the United States, the USDA determined that sodium, potassium, calcium, magnesium, iron, copper, manganese, phosphorus, and zinc were common in most municipalities.

Many of these minerals and elements are necessary for human health and welfare.

These deposits also can add flavor and depth to the profile of your beer. 

These minerals and trace elements may come from natural sources in the earth, such as silt, rocks, and organic matter deep in the aquifer or groundwater.

However, some industrial or agricultural sources may contribute to the levels.


Utility Water Treatment

Since utility water comes from many different sources, including surface water and groundwater, these water sources can pick up contaminants along the way.

For example, as rain falls into a parking lot, down into a drainage ditch, into a creek before being absorbed into the ground, the water will pick up debris, oil, even bacteria, and microbes.

Water utility plants use industrial-scale filtration to remove particulate matter from the water and then chemically treat the water for public health.

These additives may include fluoride, chloride, chlorine, among others.

Most of the time these additives stay at low concentrates, but sometimes errors, mistakes, or failures may result in higher concentrations.

Occasionally, the utility may release a press release if potentially dangerous contaminants have been released with the public drinking water.


Water Contamination

Recently, water contamination has become prominent in the news from the crisis in Flint, Michigan.

In Flint, poor water treatment led to leaching lead from old water pipes into the water supply.

Even though the city made national news, similar situations happen across the United States everyday without people knowing.

According to NDRC.org, when municipalities obtain water supply from groundwater sources, pesticides, fertilizers, and even pollution from other industrial and agriculture processes can make their way into your tap water.

However, even if the municipal supply meets FDA regulations, the infrastructure can be another source of contamination, such as in Flint.

Old pipes that transport water through the city, neighborhood, and even to your home can be a source of contamination.


For people that get their tap water from a well, the concern for contamination may be more or less concerning.

If the well is a substantial distance from any industrial or agricultural processes, the water might be better than a municipality’s.

However, the EPA lists several common contaminants that residents should be aware of with well systems, even if they aren’t using it to brew beer!


How Can Water Quality Impact Beer?

The contents of the water can have a huge impact on the final flavor of your beer.

  1. Calcium: Forms of calcium can be found as calcium chloride, calcium sulfate, calcium carbonate, or hydrated lime. These components may extract fine bittering compounds from hops. Without them, some salts may precipitate, which could cause haze or gushing, which is the overflowing or rapid release of gas.
  2. Magnesium: Magnesium can be found in the form of Epsom salt. It can accentuate beer flavor, but excessive levels can act a diuretic and laxative. However, it can be an important yeast nutrient.
  3. Sodium: Both table salt and baking soda are salts in water. Too much can add a harshness or a sour, salty taste that may accentuate beer flavor at lower concentrations. Excessive levels can be poisonous to yeast.
  4. Carbonate Bicarbonate: Such as chalk and baking soda, can promote malt flavors, but also can create harsh bitter flavors in lagers.
  5. Sulfate: Found in Epsom salt, gypsum, can give the beer a full flavor. Large amounts can make the beer taste bitter. If the yeast used is prone to create hydrogen sulfide, sulfates can cause the production of sulfur.
  6. Chloride: Another type of table salt, or a form of calcium chloride, can accentuate bitterness and enhance flavor, but too much can lead to salty flavors. Too much can be toxic to yeast.
  7. Fluoride: Fluoride is a common additive to public drinking water to promote healthy teeth. The good news is that it does not seem to impact the process of brewing beer, or the flavor or aroma of the finished beer. Several breweries have even released statements indicating their support of fluoridation of water.


What Type of Water Should You Use?

The best type of water for brewing may be filtered tap water, depending on the quality of your water.

You should begin your selection for water by determining if you tap water is acceptable for brewing or not.

You can find water quality reports online that describe the minerals, trace elements, and other components in your water. You can try to call the utility company if you are unable to find a report online.

If you see anything in the report that would be detrimental to your style of beer, you may be able to filter your tap water, or you can choose to purchase bottled water.

As you review the water quality report, take note of principal ions, such as Calcium (Ca+2), Magnesium (Mg+2), Bicarbonate (HCO3-1) and Sulfate (SO4-2). Sodium (Na+1), Chloride (Cl-1) and Sulfate (SO4-2).

These values may be described as PPM or mg/L. HowToBrew.com provides a quick resource to convert from one unit to the other.

Here are the recommended brewing levels for each:

  1. Calcium: 50-150 ppm
  2. Magnesium: 10-30 ppm
  3. Bicarbonate: 0-50 ppm (for malt based beers only)
  4. Sulfate: 50-150 for bitter beers, and 150-350 for VERY bitter beers.
  5. Sodium: 0-150 ppm
  6. Chloride: 0-250 ppm

When shopping for water filters, review the particles that the filter is able to remove.

Brita, Pur, or refrigerator filters are rated down to a certain pore size.

For example, Brita claims to be able to remove an extensive list of minerals and trace elements.

Distilled water is not recommended for brewing, as the absence of many minerals and trace elements will leave the beer lacking in favor, especially with all-grain methods. However, if you’re using a malt extract method, many extracts have minerals added back in to help guarantee proper flavor.

The same goes for reverse osmosis water unless desirable minerals have been added back in. However, distilled water is very useful for diluting the concentrations of other undesirable elements.


Correcting your Brewing Water

If your tap water happens to include minerals, chemicals, or other elements that would be concerning for the brewing process, there are several other options that you can consider.

Boiling, filtering, and dilution are all effective techniques to reduce the concentration of undesirable contaminants in your water. 



Boiling can reduce carbonate in the water by precipitating calcium and magnesium out of solution.

This helps reduce the hardness of the water.

Raising the temperature of the water reduces the amount of dissolved oxygen which can impact the chemistry of the mash.

The process can also reduce chlorine from utility water treatment, which thereby reduces chlorophenols.

Finally, boiling also sterilizes the water, preventing any trace bacteria in the water from contaminating your final product.



There are many different methods of water filtration that can be done at home.

Different filtering processes can reduce certain particulate matter in the water.

Activated carbon filters remove large particles, such as sediment and silt from water.

Typically, carbon filtration can filter out particles that are larger than about 0.5 micrometers. The carbon is typically able to absorb chlorine and organic matter from the water.

It can be fairly expensive and time consuming for large quantities of water required for large batches of beer, especially since the carbon filter will need to be replaced often. Each filter is rated for a certain number of gallons before the filter will become too full.

Specially designed inline water filters can be used to filter tap water. These kits hook up to a faucet or hose bibb to help brewers easily filter water for filling a brewing kettle or fermenter.

Another option is reverse osmosis filtration (RO) which can remove organic and inorganic matter, as well as microorganisms such as bacteria, and some minerals.

RO filters work by using pressure to force water through a semipermeable membrane.

This process includes a pre-filter and final filter.

RO systems can be installed on an entire home’s water supply.

RO filtration system can be large, expensive, and requires consistent maintenance to be effective.

RO systems for brewing claim to remove 99.9% of contaminants from the water source, even down to 0 ppm TDS.

However, note that stripping the water too much can lead to flat beer flavors.

These systems take a considerable amount of time, only filtering about four gallons per hour.

If you have very hard water, a water ionizer or water softener may be able to soften your brewing water.

Homes and businesses in areas with consistent hard water may install water softeners for the whole building.

Softening systems work by filtering water through a brine solution of minerals and salts.

Water softeners large enough to treat several gallons of brewing water are even more expensive than carbon filters or RO filters.

Water ionizers use electrolysis to make water more alkaline.


Finally, UV filters can be used to eliminate microbes and bacteria in the water source. However, UV filters will not remove any sediment, silt, minerals, or trace elements from the water stream.



The easiest way to reduce concentrations of undesirable deposits in your brewing water is to dilute the water with distilled water.

Distilled water should be stripped of any deposits, which could lead to a flat-tasting beer. Since minerals and other compounds can add depth of flavor, 100% distilled water should not be used.

However, adding in enough distilled water can reduce elements such as chlorine or chloramines, reducing salt concentrations, or any other elements in too high of a concentration.


Water Additives

If your water quality happens to be TOO pure, you may need to add minerals and trace elements back into your wort or mash.

If you need to raise the pH of your water, you may be able to add Calcium Carbonate (aka Chalk).

HowToBrew.com recommends adding chalk to the mash for making dark beers in areas with soft water.

Gypsum and Epsom Salt can lower pH and can help create “crispness”. Be careful with adding brewing salts to your mash. Too much, as discussed in the rest of this article, can have severe consequences on the outcome of your brew.

Calculating the how much additives to add to your mash can be extremely complicated and usually results in only a few grams of additives per five gallon batch.

Adding one form of additive can result in too much of another additive.

Online calculators can help you estimate how much should be added, such as BrewersFriend.com.

For example, say your tap water has only 25 ppm of calcium, and you want to increase to 50 ppm. You may be able to add gypsum (calcium sulfate). One gram per gallon would add 61.5  ppm. For a five gallon batch, you would want to add 125 ppm, so you would need 125 ppm/ 61.5 ppm, or 2.03 g.

However, this might also add 147.4 ppm x 2.03 g = 299 ppm of sulfate to the mash, which may exceed your desired concentrations unless you want to make a VERY bitter beer. Therefore, you may want to choose an alternative additive or use half and half. If you used half ppm of gypsum and half ppm calcium chloride, you would need  about 1 gram of gypsum, just under 1 gram of calcium chloride, resulting in 133.5 ppm of calcium, 147.4 ppm sulfate, and 127 ppm of chloride.


How to Tell if Water Affected Your Brew

Here some common issues that may be a result of undesirable elements in your brewing water:

  1. Gushing: The rapid release of gas in beer can cause carbon dioxide to gather, causing overflowing when the beer is opened. While primary gushing may be attributed to fault in the malt (such as modl), secondary gushing may be due to metal ions (such as iron, nickel, or tin) in the water. These metal ions can typically be removed with filtration methods prior to brewing.
  2. Sulfur Smells: All yeasts produce hydrogen sulfide during the fermentation process, however, some yeast strains produce more than others. If you smell rotten eggs during fermentation, sulfur is to blame. Active, vigorous fermentation can expel any sulfur that is produced, but slower fermentation may trap dissolved sulfur in the beer. Sulfur levels above 0.01 micrograms per liter may be detectible.
    Lagers tend to be more susceptible to sulfur tastes as the fermentation is slower and lager yeast strains typically produce more hydrogen sulfide. If you are brewing a lager style beer, consider diluting your tap water with distilled water to reduce the concentrations of sulfate. Mixing, shaking, or aerating your beer or wort can help dissolved sulfur gases to escape the wort, but also runs the risk of oxidizing your beer.
  3. Stalled Fermentation: The most common issue with poor water quality is stalling or stopping fermentation. If you transfer your wort into your primary fermenter but don’t see as vigorous activity as you anticipated, or the yeast stalls early, water may be the culprit.
    There are many contaminants in water that can be toxic to yeast. The most common contaminants are chlorine and chloramine used to prevent bacteria in public drinking waters. If you use tap water to brew beer, make sure to check your public water supply’s water quality report, or use an at-home chlorine test kit. Even excessive amounts of salt and sulfur can case stalled fermentation.
    You may need to create a stronger yeast starter to have enough healthy yeast cells to survive through to the finish, or add yeast nutrient to encourage the yeast along. If you think that water quality may be the cause of stalled fermentation, try running your tap water through a water filter or boiling it prior to brewing.
  4. Flat Taste: If your beer lacks dimension, but otherwise tastes as intended, then your water may be lacking essential minerals and trace elements. While this batch may not be rescuable, in future batches, consider adding back some minerals, either through enhanced malt extracts, additives, or by just purchasing purified water.

Choosing the right water for your homebrew will make your final product much more flavorful in the best way.

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