By Jack Horzempa
When I first started homebrewing over 25 years ago I went to my Local Homebrew Store (LHBS) to purchase homebrewing equipment and ingredients for my first batch: a can of Muntons Traditional Bitter, another can of Muntons Liquid Malt Extract, some extra hops for flavor and aroma, and a sachet of Muntons dry yeast. There was one missing ingredient from that purchase: water. The young fellow working the store informed me that if my tap water tastes good then it is good enough to brew with. I followed that advice for my first batch.
A year or so into my homebrewing avocation I purchased my first homebrewing book: The New Complete Joy of Homebrewing by Charlie Papazian. I still have that book and the pages are quite yellow from age. I learned on page 73:
“If the water you use for brewing is suitable for drinking in the United States, then there is only one thing you as a beginner [that was me] or intermediate brewer might consider doing to improve it. Some municipal water supplies have chlorine content that is excessive for brewing the absolute best beer. Using a countertop activated charcoal-type filter will remove chlorine.”
I did not know if my municipal water supplier had “chlorine content that is excessive” but I figured it would be useful to purchase an activated charcoal filter that I could screw onto my kitchen sink faucet. I have used filtered water for my homebrewing thereafter.
Water is by far the largest ingredient, by volume/weight, in brewing beer. I have read that water is > 90% of the content of beer. But from my conversations with fellow homebrewers and readings of posts on homebrewing forums it seems like water is the least considered of the ingredients. There are lots of discussions about which hops should be selected, which brand/type of malt, which yeast strain to use, etc. but there is typically little discussion concerning brewing water.
There are a variety of sources for obtaining your brewing water:
As I already discussed I receive municipal tap water and this is what I choose to use for my homebrewing. My water supplier treats this water using chloramine as opposed to chlorine. Chloramine is more stable (i.e., longer lasting) than chlorine and therefore beneficial for providing safe drinking water. Unfortunately, chloramine can be a bit more challenging to remove than chlorine. I decided to purchase a three-stage block carbon filter that I installed under my sink to provide the needed ‘extra’ filtering to remove the chloramine from my municipal tap water. A best practice for proper filtering here is a slow flow rate with something like a flow rate of 1 gallon per minute being the goal.
Another method to remove chloramine from tap water is using Campden tablets. The often-recommended dosage is 1 Campden tablet per 20 gallons of tap water. This recommended value is predicated on a ‘worst case’ value of 3 mg/L of chlorine all as chloramine of the tap water. I use Haach test strips to measure the chlorine/chloramine value of my tap water, both pre-filtered and post filtering, and I can report that my municipal tap water only contains between 0.5 – 1 mg/L of chlorine as all chloramine. If you know the value of chloramine in your tap water you can tailor the amount of Campden.
If you have a well supplying your household water the good news is that chlorine/chloramine is not a concern. A concern with using well water is when you have hard water and are using a water softener to treat the water. The water softening unit exchanges ions associated with hardness (Ca+, Mg+) with sodium ions (Na+). This increases the sodium content of your water significantly and can result in a harsh bitter flavor. All the sources I've read recommend against using softened water for brewing.
Water that comes from a spring will contain no chlorine/chloramine and therefore is appropriate for homebrewing if you have a safe supply. This would generally mean purchasing it and I personally am unwilling to pay for spring water to homebrew beer. An open artesian spring is prone to contamination exactly because it is open so I do not recommend stopping by a roadside spring to fill up.
Distilled water is pure H2O with no other contaminants and is a perfect blank slate for homebrewing. For homebrewers who are extract brewers distilled water if often recommended since the notion is that the extract already contains all of the needed mineral content for brewing. For all grain brewers, using distilled water will require the addition of brewing salts to properly build up the water for brewing.
The process of RO filtering results in a water that does not contain chlorine/chloramine and has very little mineral content (e.g., approaching distilled water). RO water can be purchased by 1- and 5-gallon units at larger chain stores such as Walmart (e.g., Primo brand). Or some homebrewers will install RO filter systems in their houses to produce RO water. If you choose to install an RO filter system in your house keep in mind that ‘waste water’ will be produced; for every gallon of purified water your reverse osmosis system produces, it will likely have used roughly four gallons. If you can capture this ‘waste water’ (e.g., use it for laundry, watering your garden, bathing, etc.) then it will not be actual waste. Just like for distilled water, for all grain brewing the RO water will need to have brewing salts added to build up brewing water.
The qualities of brewing water will have two basic impacts:
In my homebrewing practice my main concern when it comes to brewing is achieving a proper mash pH. In order to achieve a good conversion of starches to sugars (to create the wort) the mash needs to be in an appropriate range of values.
Various brewing authors recommend specific ranges for mash pH but something like 5.2 – 5.4/5.6 is often the recommended range. In much of the US the water sources are alkaline so depending upon the beer style you may not achieve a pH in this range without taking specific steps (e.g., adding lactic acid to the mash/sparge water). I can mash dark beers (e.g., Stouts, Porters) with my filtered tap water and achieve a proper mash pH value since the dark malts (e.g., Chocolate Malt, Roasted Barley Malt, Black Malt,…) are naturally acidic and they bring down the pH of the mash into the appropriate range. In contrast when I brew lighter colored beers (e.g., Kolsch, Pilsner, etc.) I need to add some lactic acid to the mash/sparge water to achieve a proper mash pH value.
The mineral content of the brewing water will also affect the achieved mash pH so altering the mineral content of the water is another method for making adjustments here but care must be taken not to negatively affect the flavor profile of the beer.
There are a number of brewing water calculators available online to predict the mash pH. The needed input for these tools is mineral content of the brewing water and the grain bill.
A very simple to use tool is called EZWaterCalculator which is an Excel Spreadsheet which can be downloaded here:
I have no personal experience with this tool so I am uncertain how accurately it predicts mash pH.
A tool I use in my homebrewing is also an Excel spreadsheet(s) called MpH which can be downloaded here:
I have found that the predictions provided by MpH closely align with my measured mash pH values.
There are a number of ways to determine the mineral content of your brewing water. First a quick primer on which minerals are important to brewing from both a mash pH and flavor consideration:
In addition to the above you also need either alkalinity (CaCO3 ppm) or bicarbonate (HC03 ppm).
I found the mineral content of my tap water by contacting my municipal water supplier and they mailed me a Laboratory Report containing the needed information.
An alternative method is to send your water (tap water, well water, purchased spring water) to Ward Labs and request they analyze the water:
If you are in the mood to analyze the water yourself there are kits you can purchase and perform your own chemical analysis:
A benefit of having your own water test kit is that if you have a variable water source (e.g., well water) it permits you to regularly (e.g., once a month/season) test your brewing water for changes.
Measure you mash pH
While I feel comfortable in the predictions of MpH for my mash pH I do also measure my mash pH for every batch as part of my overall quality control (QC) process. My goal is not to achieve a specific mash pH, but simply to fall within a range of 5.2 – 5.4 so I am satisfied just using pH test strips. I choose to use ColorpHast pH Strips.
For homebrewers who prefer greater accuracy/precision a pH meter (and accompanying calibration/buffer and electrode storage solutions) is the appropriate choice.
Impact of Brewing Water on Beer flavor
The specific mineral content of brewing water is sometimes referred to as seasoning your beer. An analogy here is how salt is used to season your food. But just as how salt can influence the flavor of your favorite dish the other constituent elements of that dish will impact how the salt addition is perceived.
Below are how minerals can impact the flavors and sensory aspects of your beer:
Increased levels of sulfate will enhance the hoppy aspects of the beer proving a “crisp” bitterness and will provide a mouthfeel perception of a dry finish.
Chloride will enhance the perception of sweetness and fullness of the beer and provide an overall aspect of maltiness to the beer.
The contributions of sulfate and chloride are discussed above but the relative proportions of these two minerals is important to consider for a given beer style. For example, a 2:1 ratio would be a good choice for hoppy beers like IPAs while for a malty beer like a Stout or Porter a 1:2 ratio would be more appropriate.
Sodium in concert with chloride can enhance both the sweetness and fullness perceived in the beer. But since sodium plus chloride equals NaCl (salt) too much sodium can push the flavor towards minerally/salty. Also, in the presence of sulfate sodium creates an unpleasant harshness (see discussion of softened well water above).
A minimum level of calcium (50 ppm) is needed in the brewing water. It does not influence the flavor but it is an important yeast nutrient and provides other benefits such as aiding in the precipitation of proteins during the boil. Calcium also contributes to lowering the mash pH.
Magnesium is not absolutely needed in brewing water since malt will provide all of the magnesium needed for yeast health. The important thing here is to ensure the magnesium level is low (e.g., less than 40 ppm) since elevated levels of magnesium in the brewing water will have negative impacts. It can provide a sour/bitter taste at levels over 40 ppm and at much higher levels it can provide a laxative effect.
If using distilled or RO water you will need to add water modifiers, also referred to as brewing salts. Some common brewing salts are:
Kai Troester provides some examples of water profiles for certain styles of beer at his website:
I have extracted one example from this website below for Pilsners showing the suggested water profile and the necessary brewing salt additions in units of grams per unit of water.
Another source of water profiles is the MpH tool previously discussed; one of the sheets is “Water Profiles”.
If using tap water, the water can still be modified to achieve a given profile but you need to know the minerals in your tap water to make the proper adjustments. If your tap water is lower than desired for chloride you could add some calcium chloride to give it a boost. Similarly, if you would prefer increased sulfate you could add some Gypsum (calcium sulfate).
If your tap water has more of a specific mineral than desired (e.g., magnesium is too high) you could purchase some distilled or RO water and dilute your tap water to reach your desired level. You may need to add some brewing salts to get other desired mineral levels (e.g., chloride, sulfate) back into your desired range. This is a bit like playing the Hokey Pokey but the water tools easily permit you to play around and achieve a specific water profile.
Brewing water can be as easy or complicated as you want to make it but there are a few details that I think are necessary:
For my homebrewing practice, achieving a specific water profile is beer style dependent. Some examples of beer styles where I take steps to modify my tap water to create an appropriate water profile: Kolsch, English Bitter Ale, Bohemian Pilsner (Czech Pale Lager), and New England IPA. Having stated that, targeting a specific water profile for every beer style is not a bad idea.
This article provides a cursory view of Brewing Water. For the interested student, I suggest the book: Water: A Comprehensive Guide for Brewers (Brewing Elements) by John Palmer & Colin Kaminski.
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