Calcium is one of the most important minerals in the finish and flavor of a beer. It can create the soft finish of a pilsner or the crisp finish of an IPA.
What is the role of Calcium in brewing?
Besides affecting the finish of your beer, Calcium has several other functions in the fermentation process. The first is that calcium can help control pH during mashing and keep it more consistent. This is especially important when you are trying to recreate a beer you’ve previously brewed or trying to follow a new recipe.
Calcium also protects yeast when working with higher gravity. Because of this you’ll often see higher calcium levels in stronger IPAs. But if the levels are too high then Calcium can interfere with Magnesium which can harm your fermentation.
Maintaining the right level of calcium in your brewing water can improve the clarity of your beer. Many homebrewers aim to reduce haze, and keeping an eye on calcium levels can help with that. While commercial breweries often use fining agents to enhance clarity, calcium also plays a key role in the process.
Calcium amounts in your brewing water
Even though Calcium is one of the most important minerals in your water, there are a wide range of concentrations used based on what type of finish you are wanting your beer to have and the structure of the beer.
For paler beers (think Pilsner), 50ppm or lower is the target. That will give your beer a soft finish which is ideal for a lighter refreshing beer.
*ppm is approximately the same as mg/L
50ppm- 100ppm is going to be the most common range for most beers. This gives your brew the pH control benefits, the clarity, and structure to support higher gravity.
100ppm-150ppm is used mainly for darker beers or some IPAs. This will give more structure for higher gravity beers and a firmer finish.
Above 150ppm can be used, and a lot of famous brewing cities have water in the 200-300ppm range. But at this level it may negatively affect your fermentation or cause unwanted haze in your finished beer.
How to Measure your Calcium levels
There are two methods to measure Calcium levels, the Craft Pro DIY Test Strips or the Craft Pro In-Lab Test Kit.
The Craft Pro DIY Test Strips will give you an easy, affordable way to measure Calcium with each batch. These will measure Calcium along with Hardness, Magnesium, and several other key factors for your brew.
The test strips will give you results in a range, meaning you will know if your Calcium is 0-50 ppm, 50- 100 ppm, etc.
The In-Lab Craft Pro Test Kit will allow you to send a water sample to our EPA-Certified lab and get exact concentrations for your brewing water or any brewing liquid.
You will know exactly what your Calcium is, as well as exact concentrations for other parameters and several brewing specific calculations such as Residual Alkalinity.
When measuring your water for Calcium level, it’s also important to measure your Magnesium. Because Calcium can interfere with how yeast utilizes Magnesium, you’ll want to ensure that your Magnesium levels aren’t too low.
A good rule of thumb is that your Magnesium levels should be no lower than your Calcium levels, but your grain will produce anywhere from 50-100ppm Magnesium. So, if your Calcium levels are higher than 50-100ppm, you may want to add some Magnesium salts. Since this is grain dependent it will require some testing.
How to lower your water’s Calcium levels
Boiling to reduce Calcium?
Some brewers recommend boiling your water to reduce the negative effects from high Calcium. While Calcium is a mineral that isn’t technically removed when boiling, it can temporarily reduce hardness. This is dependent on the bicarbonates in the water, so it is not a consistent way to reduce Calcium’s effects.
Besides being inconsistent, you may make other minerals more concentrated by reducing the overall volume of water because of the evaporation when boiling.
Boiling to reduce Calcium is still relatively common with homebrewers but it’s not the most precise.
Filtering out Calcium
The most common recommendation to remove Calcium will be with a Reverse Osmosis (RO) system. This works by forcing your water through a semi-permeable membrane, which essentially sets your water profile to 0. Removing all the minerals from it.
It is still important to test your water after it’s been RO filtered because it can affect the acidity and depending on the filter, it may not actually filter out everything. You still need to know exactly what you are starting with.
The way most brewers use RO water is by getting it as close to zero as possible, then building up their water profile to meet their needs. This can add complexity and cost to the process but is the most guaranteed way to get the water profile you want. Luckily there are some great brewing calculators online that can help you with this process.
Diluting your water
If your Calcium levels are high another option is to Dilute your water with RO or distilled water. This will just be a matter of doing the math to figure out the adjustments. If you want to aim for 100ppm and you are currently at 200ppm, you will need to use a 1:1 ratio if your RO water is at 0ppm.
Calculating your Dilution
Let’s go through the math for a more complex example.
In this example you are targeting 50ppm, but your tap water has 200ppm, and you want to end up with 2 L of water.
Amount of Tap Water = Desired Water Amount x (Desired Calcium/Tap Calcium)
Amount of Tap Water = 2L x (50ppm/200ppm)
Amount of Tap Water = 2L x 0.25
Amount of Tap Water = 0.5L
Now if you want to target 2 L and you need 0.5L of tap water. 2L – 0.5L = 1.5L of RO water.
This formula will let you target any Calcium level with any volume of water.
How to increase your water’s Calcium levels
There are two main methods you’ll want to use to raise your Calcium levels, Calcium Sulfate and Calcium Chloride.
Calcium Sulfate, also known as Gypsum, is an excellent choice to raise Calcium levels and is commonly used in pale ales. This is because it can give the beer a dryer finish which can enhance the bitterness. It also makes the natural hops flavors more noticeable which is what many brewers are targeting when making pale ales.
Calcium Chloride is another common choice. Typically used when you are wanting to avoid adding sulfates because you are producing a more malt focused beer.
Many brewers use a combination of Calcium Sulfate and Calcium Chloride based on sulfate levels and how they want to balance the hops and malts flavors of their beer.
Like with everything when brewing, ensure you are using food grade products from a trusted supplier.
Conclusion:
Calcium is one of the most important minerals in brewing great beer. Understanding how it affects the finish and stability of your brew can help you control the taste and feel of your beer. But it’s also important to understand how it interacts with other minerals like Magnesium.
