By: Peter Morrissey
When it comes to making beer, the largest single ingredient is water - making up 90-95% of all the ingredients used. Being such a significant ingredient, it’s a little ironic that it’s often overlooked by homebrewers and is sometimes the last thing they turn their attention to in order to improve the quality of their brews.
At every step in the brewing process water is utilized in some way, so it’s important it gets the attention it deserves to ensure you’re getting the most out of it. Even some minor tweaks and adjustments to some of the elements that make up your water profile can yield massive results and improvements in the end beer that is produced.
Thankfully with the vast array of (free) brewing software available, you don’t need to be a science major to understand and work out how to adjust your water for brewing beer. This means that water chemistry adjustments are well within reach of homebrewers of all skill levels, and is a critical step to getting your homebrewed beer to taste akin to commercially available craft beer.
In this article, we’re going to dive into the world of water chemistry. We’ll try to keep the sciencey stuff to a minimum and focus on how different elements of water impact your beers and how you can leverage the power of brewing software to help determine what adjustments you should make to your water to improve it and make it suitable for the style of beer you’re making.
What Is Water Chemistry In Brewing?
Water chemistry in brewing is the process of adjusting some of the salts, minerals, and pH in the water that is used in the brewing process - namely in the mashing and sparging stages. When we talk about water chemistry in brewing, we’re looking at and adjusting the following elements within our water;
- Calcium (Ca)
- Magnesium (Mg)
- Sodium (Na)
- Chloride (Cl)
- Sulfate (SO4)
Why Is Water Chemistry Important When Brewing Beer?
As previously mentioned, up to 95% of beer's composition is water, so tweaking and adjusting the water used in the brewing process can have a significant impact on not just how it tastes, but also how it feels on the palate - also known as mouthfeel. Different styles of beer will call for different water profiles to help accentuate particular elements of the beer.
For example, IPA’s will generally have elevated levels of sulfates and reduced chloride levels to help emphasize the hop flavors that are key to the style. For more malty beers, the chloride and sulfate levels are closer together to help balance hop and malt flavors against one another.
Ever wondered how New England IPA’s or Hazy IPA’s get that soft, pillowy mouthfeel? Sure, the grist that is used plays a part, but more importantly, it’s a chloride-to-sulfate ratio in the brewing water that is heavily stacked with chloride that makes this happen and gives a thick, full mouthfeel.
Making adjustments correctly can help turn a good beer into a great beer and is often the missing piece of the puzzle for many homebrewers who strive to make beer of a similar caliber to the commercially available stuff that we all love - and probably inspired us to start brewing our own beer in the first place. The freshest ingredients, loads of hops, and the best processes will only get you so far on the road to Flavortown or a hop-induced euphoria - you really need to be tweaking your water to make it all the way!
A failure to adjust water chemistry appropriately will likely create a beer that feels somewhat lacking - with flavors often seeming dull, muted, and just kind of blended together in a muddled mess with nothing really standing out. It’s kind of hard to explain but if you’ve been brewing for a while you’ll probably know what I’m talking about - it can be especially evident if you taste one of your (non-water-treated) homebrews head-to-head against a commercially made craft beer of a similar style. Sticking with our IPA example, you’ll notice how much brighter the commercial one tastes, with the hops really shining and bursting with flavour. That is what water chemistry, and in particular, sulfates will do. Let’s make yours like that, shall we?
What Type of Water Should I Use for Brewing Beer?
As a brewer, there are a number of different options available to you for sourcing water. There are pros and cons to each so it’s ultimately a personal decision based on what you have available and potentially your brewing budget as well.
What is key though is knowing the mineral content of whatever water you are using so you can understand what adjustments need to be made to get to your desired water profile.
Spring Water is a readily available water source for most brewers and can be purchased at loads of places like supermarkets. The cost can add up fairly quickly though when you need several liters or gallons, and if the mineral content isn’t printed on the packaging you may need to contact the manufacturer to find out exactly what’s in it.
City or town water is cheap and accessible to most brewers, with almost 75% of the world's population having access to a safely managed water source. However, these managed water sources often contain chlorine and/or other potentially unwanted additives and contaminants that mean some additional treatment may be required before it’s suitable for brewing.
Chlorine can easily be removed by adding a campden tablet to the water, and many other undesirable compounds can be removed by using simple household water filters.
As a general rule, if your water tastes good to drink straight out of the tap, it’s going to be a good starting point for making beer. If it tastes or smells a bit funky, you may need to invest a little time and effort into treating it to get the best results in your finished beer.
Many water providers will make water quality reports available that include the mineral content which can be used as the basis for building your brewing water profile. If a water report isn’t available then you may need to test it yourself or pay for a test to be completed, as knowing what is in your water is critical to knowing what to adjust and by how much.
Distilled/Reverse Osmosis Water
Distilled or Reverse Osmosis water is arguably the best type of water to use if you can get it, or don’t mind spending the money to get it. Both of these water types have undergone treatment (either distillation or multiple levels of filtration) to remove all of the minerals and salts within them.
Using these water types allows brewers to start with a “clean slate” with all the key minerals being at 0 (or at least negligible levels) which makes building a water profile a little easier as you’re essentially starting from scratch.
Like with spring water, buying distilled or reverse osmosis water is going to be more expensive than using town/city water but may be worthwhile in some circumstances.
If you’re serious about water treatment you can even buy your own reverse osmosis system and hook it up to treat your city/town water from a tap or faucet in your house/apartment, though they are known to be slow and somewhat inefficient by generating a fair amount of waste water as part of the filtration process.
How Can I Know the Alkalinity And Mineral Composition Of My Water?
City Water Report
A city water report is a great way to find out what’s currently contained in your water. Many municipal water providers will post water quality reports online (typically quarterly), however, if you can’t find it yourself it’s definitely worth reaching out to your provider and asking if they can send you one.
Here’s an example of a water report posted online from our local water provider that is actually tailored specifically to homebrewers (thanks Sydney Water!);
In this report we’ve got all the key metrics that we need to adjust our brewing water. Where a number range has been provided, we simply take the average value of the two numbers, since brewing software requires specific numeric values, not ranges. For example, magnesium has a range of 3.36 - 4.29 mg/L which has an average of 3.83 so this is the value we’d enter into our brewing software for magnesium.
It’s also worth pointing out that some reports will give values in mg/L (like above), and others will state ppm (parts per million). Thankfully, both mean the same thing so the values are interchangeable.
If you’re not able to obtain a city water report, then an at-home testing kit is another option to help you determine the composition of your brewing water.
There are plenty of options out there, but a popular one is the “Lamotte BrewLab Basic Water Test Kit” which was developed in conjunction with well-known homebrewing author, John Palmer, and gives you 7 important water test factors you need for brewing (chloride, sulfate, alkalinity, total hardness, calcium hardness, magnesium hardness, and sodium).
It’s worth purchasing a pH meter as well as a fast and reliable way to quickly determine the pH of your water (if your testing kit doesn’t include one). pH is a critical element during the mashing process, so a pH meter really is a must-have to ensure your mash is within the correct range. More on that below.
What Factors Of Water Chemistry Are Important When Brewing Beer?
The term “pH” stands for potential hydrogen and is a measurement of how acidic or basic (non-acidic) a solution is. It is measured using a numerical scale from 1-14 with 1 being very acidic, 7 being neutral, and 14 being very basic.
To give some context to this, solutions like lemon juice or vinegar will have a pH of 2 (very acidic). Soapy water is on the other end of the scale with a pH of around 12 (very basic) and pure water will have a pH of 7 (neutral).
In terms of brewing, the pH is most critical at the mashing stage, where a slightly acidic pH of between 5.2 and 5.6 is considered the sweet spot for most beer types. Getting the pH within this range is important for many reasons. It ensures enzymes can effectively convert the starches from your malted grains into sugars, improves yeast health, wort clarification as well as the overall flavor profile of the final beer.
A pH that is too high will extract undesirable tannins from the grains which can cause an unpleasant flavor or sensation, often likened to sucking on a wet tea bag. A pH that is too low will result in muted flavors and reduced body in the finished beer as it will be too acidic.
Thankfully pH meters (instruments used to measure pH) are very affordable and are definitely a worthwhile investment for any homebrewer. They work by submerging the pH meter’s electrode into a solution which then displays a pH reading on its screen within a matter of seconds. The meters are sensitive and require constant calibration to remain accurate, but if well looked after are a vital tool in a brewer's arsenal. Just make sure you get one with a replaceable electrode since they’re a consumable part that will eventually wear out. Automatic Temperature Compensation (ATC) is another great feature to look for so you can measure the pH at temperatures other than the meter's calibrated temperature (typically 20°C/68°F).
pH can also be measured using paper test strips. These strips are submerged in a solution, then change color according to the pH and are compared against a color chart to give an approximate pH value, however, the results will not be as accurate as when using a pH meter.
An ion is a charged atom or molecule that has either a positive or negative charge depending on whether the number of electrons is greater or less than the number of protons. Ions with a positive charge are called “cations”, and in brewing water, these are calcium, magnesium, and sodium. Ions with a negative charge are called “anions” and in brewing water, these are bicarbonate, sulfate, and chloride.
Increased sulfate levels in a beer can enhance its dryness, and can also promote bitterness, hop character, and crispness. A lack of sulfate can leave a beer seeming too full or malty, perhaps with a sweet or cloying-like finish.
A minimum sulfate level of 40 ppm is suggested to help beers dry out adequately in the finish. Hoppy beers can have levels up to 300 ppm for sulfates to really make the hops shine.
Not to be confused with chlorine, chloride helps to accentuate a fullness or roundness of the flavor in beer - in particular, it can enhance malt sweetness.
Concentrations in the higher range up to 200ppm can give a full malty taste and can help to enhance mouth feel
Chlorides and sulfates tend to directly impact one another as they have opposing effects on beer - they are often directly compared using a chloride-to-sulfate ratio and are arguably the two most important minerals within your brewing water.
A chloride-to-sulfate ratio of 1:2 (or higher) will give a drier, hoppier flavor profile. The inverse ratio of 2:1 will have a more rounded, less bitter, and maltier balance of flavors.
Calcium can help to lower (acidify) the pH of the mash and the amount of calcium present (along with magnesium) determines the hardness of the water. It also improves the flavor, clarity, and stability of the finished beer.
Small amounts (less than 50 ppm) will lead to a soft finish - ideal for lighter styles like an American Lager.
Moderate levels (50-100 ppm) will generally lead to a well-rounded finish.
High levels (100-150 ppm) will give a firm finish and are often used in some dark beers and IPA’s with higher alcohol content. Be careful if using elevated levels of calcium though as it can block yeast access to magnesium which can impact yeast health and fermentation performance.
Magnesium is a critical component of water for sufficient yeast health and along with calcium contributes to water hardness.
Slightly increasing the magnesium level can help to enhance the perceived bitterness within a beer as well as promote hop flavor/character.
Sufficient levels of magnesium will typically be in the wort from the addition of brewing malts. The commonly recommended upper limit for magnesium is 40 ppm - staying below this limit should prevent any impact on the beer flavor, so make sure you’re aware of how much magnesium is in your base water and how much will potentially be added by your grist before making further adjustments.
Sodium has no chemical effect in brewing. It can be used to adjust the perceived flavor of the beer by enhancing its sweetness. Very few beer styles will call for increased sodium levels (though some styles like a Gose do call for increased levels of up to 250 ppm). Most beer target water profiles will call for no more than 20 ppm so if your source water profile contains less than this then you shouldn’t need to worry about adjusting it.
Alkalinity refers to the ability of a solution to resist or buffer a change in its pH level when acid is added. It is measured by the amount of carbonate and bicarbonate contained within the solution.
The higher the alkalinity level, the more it will resist or neutralize acids being added - so more acid will need to be added to get the desired pH level when compared to a solution with a lower alkalinity level.
What Salts/Minerals/Acids Should I Use For Adjusting My Brewing Water?
Now we know what the key components of your brewing water are and how they can influence the profile of your beer, the next thing to look at is what minerals and acids you should have in your brewing inventory for making water adjustments.
Thankfully, most adjustments can be made with just a handful of ingredients that are relatively cheap and easy to come by. Most are non hazardous too (with the exception of acid, where basic protective equipment like gloves and glasses should be worn when handling). Let’s go through them all below;
Campden tablets are made of potassium metabisulfite and are used to remove chlorine or chloramine in your water. A little bit goes a long way with a single tablet being able to treat up to 10 gallons of water.
We typically split a tablet in half with one half going in the mash/strike water and the other half going in the sparge water for a typical 5 gallon/19 litre batch. They’re cheap and readily available from most homebrew shops and are a must have if you’re using town/city water that almost certainly contains some level of chlorine.
Gypsum is also known as calcium sulfate, and as you would expect from this, it contains calcium and sulfate. Adding gypsum will cause an increase in both of these minerals and will slightly lower (acidify) the mash pH as well.
Adding calcium chloride will increase the levels of calcium and chloride within your water. It will also slightly lower (acidify) mash pH.
Also known as magnesium sulfate, epsom salts will increase the levels of magnesium and sulfates within your water. There are different varieties of epsom salts available so make sure you’re getting the food grade version to ensure it’s fit for use in your water.
Lactic or Phosphoric Acid
Either lactic or phosphoric acid can be used to lower (acidify) the pH of your water. Some brewers prefer phosphoric to lactic as they believe lactic can lead to some unwanted changes in flavor, particularly if you need to add large amounts.
The five items listed above are the key ones to have for the majority of brewers who will need to reduce the pH of their brewing water to make it more acidic.
If you have an acidic water source with a low pH that needs to be raised, then you may need to use the following;
Baking soda is the common name for sodium bicarbonate, and adding it to your water will increase the alkalinity along with the pH. It will also slightly increase the sodium level.
Calcium Carbonate, also known as chalk, will increase the alkalinity and the mash pH and will also add a small amount of calcium to your water. Baking soda is often preferred to use instead of calcium carbonate to increase alkalinity as it is more easily dissolved in water.
When it comes to measuring out your brewing minerals and salts, you’ll often be dealing in grams/ounces and tenths of grams/ounces, so a precision scale is a worthwhile investment to make this possible. Most homebrew shops will sell them, but there are plenty of options online on sites like eBay, Amazon, etc.
Manipulating pH Levels For Homebrewing
Knocking Down Water Alkalinity Methods
When measuring the alkalinity of a solution, we typically use CaCO3 (Calcium Carbonate) or HCO3 (Bicarbonate) - this is also referred to as “temporary hardness” in water. If you have a high level of alkalinity, it may be preferable to treat it prior to mashing to help lower the alkalinity level. Here are some methods you can use to do so;
Boiling water causes the bicarbonate ion to become a carbonate ion which then binds with calcium and precipitates from the water - thereby reducing the calcium and carbonate content. You can typically get to around 30-40ppm by boiling which makes the water much more receptive to acid additions for further adjusting pH levels.
Adding acid to water converts the bicarbonate alkalinity into carbonic acid (by adding hydrogen to it), which in turn lowers the alkalinity and pH values of the water. Phosphoric and lactic acid are common varieties used for adjusting the pH of your water.
Water that is treated via reverse osmosis system will typically have a finishing pH of around 6 - 6.5. Since the reverse osmosis treatment will typically remove up to 98% of all minerals and contaminants within water, the alkalinity and bicarbonate content of reverse osmosis treated water is very low and therefore easily adjusted with acids.
You can dilute your source water with reverse osmosis water too to help soften it if it’s particularly hard or alkaline.
Methods To Raise Water Alkalinity
In some cases, your water source may be significantly lacking in alkalinity which means the water doesn’t have the ability to effectively neutralize any acids that are added, which could lead to pH levels falling to unexpectedly low (acidic) levels. There are a couple of ways to add alkalinity back into your water if you need to;
Alkalinity can be increased by adding baking soda (sodium bicarbonate) or chalk (calcium carbonate) to your water.
Generally speaking, malts that are used in brewing are acidic and they will generally lower the pH of the mash water after being doughed in. Darker malts tend to be more acidic than lighter ones so keep this in mind when building your recipe and thinking about how it will impact your water profile.
Putting It All Together With Brewing Software
Brewing water and chemistry is complex, and you don’t necessarily need to fully understand every aspect of brewing water chemistry to adjust it. Most popular brewing software applications will have a feature that will do all the calculations for you and provide you with a specific list of what you should be adding to your water and exactly how much.
We like to use Brewfather - it’s free (with some restrictions, but importantly the free version does give you access to the water profile functionality), and it is cloud-based so you can use it on a PC/Mac or a mobile device and any changes you make on one platform will automatically sync and be visible on the others. There are other software options available too like Bru’n Water and Beer Smith - use whatever you like best, the concept will be the same across all of them, but for the purpose of this article we’ll look at Brewfather.
To get going with Brewfather, you need to enter the values for what is currently in your water as a “Source Profile”. Next, select an appropriate “Target Profile” within your Brewfather recipe which is what you want the mineral content of your water to be. Some example profiles would be “Pale Ale”, “Balanced”, “Lager” or “Hoppy” - these are just some of the default target profiles available in Brewfather, and you can of course add your own profile if you wish as some recipes may specify a particular water profile to use.
In the example below you can see how we’ve set up our source and target water profiles. Our target is a “Balanced” profile for a Cream Ale recipe we’ve been working on.
There is an “Auto” button and once pressed, our recipe is updated with a list of what we need to add to the mash and sparge water to get as close as possible to our desired water profile.
It really is pretty simple and you can adjust the settings to select what ingredients you have available for water adjustments (so the software doesn’t tell you to use things you don’t have available).
So even if I forget the role that gypsum plays in my beer, I know that I need to add 1.45g of it to my mash water for this recipe to get as close to my target profile as possible.
Put your faith in the software and give it a try and see for yourself what a difference water adjustments can make to the flavor profile of your homebrew. We’ll never forget that first brew we made after adjusting water chemistry - it was such a night and day difference and our only regret is not looking into making water chemistry adjustments sooner!
How can you ensure the correct ph level when brewing beer?
You can use a pH meter to measure the pH of your water. Measure your source water prior to adding any grains or other minerals to it in order to accurately determine its pH. Enter the details of your water, recipe, and what acid you have available into brewing software like Brewfather and it will tell you how much acid needs to be added to reach your target pH - typically between 5.2 and 5.6.
After doughing in your mash, leave the grain bed to settle for 10-15 minutes before taking a pH reading and then make further adjustments if necessary to get into the 5.2 - 5.6 range. The mash pH is a moving target as it will change and evolve throughout the mash, but if you hit the right number at the start it will generally take care of itself throughout the rest of the process.
Don’t forget to treat your sparge water as well - it’s generally considered OK to have your sparge water pH at less than 6, but we like to stick within the 5.2 - 5.6 range for sparge water as well.
What is the importance of water hardness in brewing beer?
Water hardness refers to the amount of dissolved calcium and magnesium within the water. Higher levels of these minerals will make hard water, and lower levels make soft water. Good brewing water should be moderately hard as it will contain sufficient levels of calcium for most beer styles. Hard water is also known to enhance yeast flocculation, hot break and can also prevent the buildup of beer stone.
How does temperature affect water chemistry in brewing beer?
Higher water temperatures will have a higher rate of chemical and metabolic reactions, and can also skew pH readings. It’s therefore important that when measuring your mash pH, the reading is taken at as close to room temperature (20°C/68°F) as possible so samples should be cooled by putting them in a small ice bath or briefly in the fridge/freezer to drop the temperature as rapidly as possible.
It’s also a good idea to cover the sample with foil or cling wrap to try and prevent evaporation which can lead to inaccurate readings from your sample. Some pH meters have Automatic Temperature Compensation (ATC) to allow for readings to be taken at varying temperatures, but putting the sensitive electrode into hot solutions such as wort will likely reduce its lifespan.
Peter is a homebrewer from Sydney, Australia. Like many others before him, Peter got started in homebrewing after being gifted a homebrewing starter kit from his wife way back in 2015. A simple hobby soon grew into a borderline obsession, and Peter has been documenting his brewing journey in recent years with recipes, guides, brew days, equipment reviews, and other insights through his website Birallee Brewing - named after the street where it all began. Peter loves researching and finding ways to improve his beers, as well as trying different beer styles and brewing techniques.