This month, we’re continuing our series of blogs taking a closer look at the four main ingredients in beer. Make sure to check out our last blog about malted grains and stay tuned for our upcoming blogs about hops and yeast. But for now, we’re talking water, the role it plays in brewing, and some common misconceptions.
Before we get into the finer details about water used in brewing, let’s take a second to talk about extract vs. whole grain brewing. A lot of what follows in this post is really only important for all grain brewers. Since extract brewers are using dehydrated wort that has already gone through the mashing process, added water plays a diminished role. As a general rule of thumb, if your water tastes good to drink, it should be fine to make good beer through extract brewing.
For all grain brewing, the most important factors you want to know about your water are its pH balance, hardness, and alkalinity.
pH measures the acidity of water and is rated on a scale from 0 to 14. 7 is considered neutral. Any pH over 7 is basic or alkaline and any pH under 7 is acidic. The pH of your water/mash/beer will affect fermentability, enzymatic activity during the mash, and the taste of the final product. Beer should be acidic and have a pH somewhere between 4.2-4.4. If it gets much higher than that, the beer will become harsher and not taste as crisp and fresh. If beer’s pH is much lower, it can introduce tart flavors.
It is a common misconception that you need to be concerned about the pH of your water before starting to brew. It is much more important to make sure your mash and final product have the correct pH. You want your mash to achieve a pH balance between 5.1 and 5.8 (ideally between 5.2-5.5).
Most tap water in the United States is slightly alkaline. Malted grains tend to be acidic with specialty malts being more acidic than base malts. This means that the grain bill can have a large impact on the pH of the mash. Rather than fret about how alkaline your water is, you should aim to pair your water’s alkalinity with a grain bill that will achieve the correct mash pH.
You can buy pH test strips online to use while brewing. Make sure to purchase strips that are sensitive enough to accurately show that you have hit the 5.1-5.8 range.
The main goal is to hit the right pH during the mash, but before we talk about how you can make sure to hit that target pH, let’s talk about hardness and alkalinity.
Hardness and Alkalinity
Hardness indicates how much calcium and magnesium ions are found in water. Most water in the U.S. is at least moderately hard, but that is just fine as calcium is key for brewing. Except for some extreme cases, you probably won’t need to worry about water hardness.
Alkalinity measures how resistant water will be to a change in pH.If your water is high in alkalinity, you will have to make certain adjustments to account for it. For example, if you’re brewing a light beer like a pilsner that uses almost entirely base malts, you’ll probably need to make use of lactic acid as base malts probably won’t be acidic enough to achieve the correct mash pH. Water with moderate to high alkalinity suits itself well to darker beers that require more specialty malts. That’s because darker grains tend to be more acidic which will help to hit the target range.
A lot of this will be highly dependant on the specificities of your water and the recipe you use. Some level of trial and error will be necessary to figure it out.
For a greater, more in-depth look at water, minerals, alkalinity, and pH, make sure to check out this article.
To help find a water report for where you live, check out the EPA’s database.