Andrew Chainless
Calcium and magnesium are two important minerals that can have a significant impact on the brewing process. Both of these minerals can affect the taste, clarity, and overall quality of your beer.
How does calcium affect brewing?
Calcium is the main ion affecting water hardness. It is beneficial to the enzymatic processes of mashing and important for yeast cell walls.
Normal wheat or barley mash has enough calcium for yeast health. In the mash, calcium reacts with malt phosphates (phytins), lowering the pH of the mash and precipitating calcium phosphate into solution and releasing protons. Calcium improves sedimentation of malt and yeast, and limits the leaching of silicates from the malt husk. It also reduces the turbidity of the beer and the possibility of “hashing”, speeds up the filtration and flushing of the mash, and has a positive effect on the taste of the hops. The ideal range of calcium in the water for ales is 50-100 ppm. Exceeding these values can cause excessive deposition of phosphates from the solution, which are important nutrients for yeast. Since oxalates (oxalic acid salts) are also released from the solution during the same reactions, insufficient amounts of free calcium ions lead to the formation of beer stone on the equipment (calcium oxalate). To avoid its formation, the recommended concentration of calcium in the water is at least 40 ppm. Lower concentrations may be acceptable for beer production like pilsner, with the understanding that additional measures may be necessary to ensure proper beer clarification and beer stone removal.
Using water with a low calcium content will not affect fermentation in any way, since barley and wheat have enough calcium for the yeast. The main problems with using such water are the deterioration of yeast sedimentation and the formation of beer stone. These issues can be addressed by methods such as lagerization of beer, filtration, and chemical treatment of equipment to remove limescale. The calcium content should roughly correspond to the level at which the particular yeast has evolved. For example, English yeast evolved in an environment with a high calcium content, while Czech yeast evolved with a very low calcium content. Another consideration is that the calcium content of the water can be varied to increase or decrease the yeast’s ability to settle. For example, if the yeast precipitates prematurely, the calcium content can be reduced to prevent this situation.
In lager production, water with low calcium content is always used for best results. Increasing the calcium content can be a useful tool to lower the pH of the mash water. Calcium has little effect on the taste of beer, but it forms vapors with anions that can increase mineral flavor at high concentrations. Another problem that can be encountered with high calcium concentrations is that calcium replaces magnesium in yeast metabolism, which negatively affects yeast health and performance. Avoid excessive calcium when yeast performance is below expectations.
How does magnesium affect brewing?
Magnesium is the second ion that determines water hardness. It emphasizes sour and bitter flavors when present in low concentrations, but makes them astringent when present in high concentrations. Magnesium is a nutrient for yeast and an important co-factor for some enzymes. Like calcium, magnesium reacts with malt, but with a weaker effect compared to the former. The preferred concentration of magnesium is between 0 and 30 ppm. It is not recommended to exceed a value of 40 ppm. A minimum value of 5 ppm has a positive effect on yeast settling – barley or wheat in the mash will easily provide this concentration. Increasing the concentration of magnesium in the water to lower the pH is ineffective because the allowable concentration of this ion in brewing is low.
The Verdict
Calcium and magnesium carbonates are components of water hardness. They are completely safe for humans and are simply necessary for making beer.
Calcium – contributes to the extraction of bittering components from hops and can also increase the turbidity and viscosity of the product due to the precipitation of oxalates.
In the mashing process it can form precipitates of carbonates and phosphates, lowers pH of wort, causes gelatinization of starch granules and stabilizes alpha-amylase. At high initial concentration during fermentation it can bind organic matters, depriving enzymes of the nutrient medium, and at low concentrations it is able to neutralize lecithin and peptone which have toxic effect on yeast.
Magnesium emphasizes the smell of beer, but in excess can give a tart bitterness. If the magnesium content is above 125 ppm the beer can have a pronounced diuretic and laxative effect. In the mashing process it is important for the work of some enzymes and lowers the pH of the wort, but less than calcium. It is important for the nutrition of the yeast during fermentation.
| The element | Normalized value | Effect of water on the taste of beer | Influence on the mashing process | Influence on the fermentation process |
| Calcium (Ca2+) | 5 – 200 ppm | Contributes to the extraction of bittering substances from hops. May increase turbidity and viscosity by precipitation of oxalates. | Decreases wort pH. Promotes precipitation of carbonates. Gelatinizes starch granules. Stabilizes the alpha-amylase. Reduces the extraction of tannins and reduces color. Forms insoluble salts with carbonates and phosphates. | Can bind organic matter, depriving enzymes of a nutrient environment. Low concentrations. Neutralizes peptone and lecithin, which have a toxic effect on yeast. |
| Magnesium (Mg2+) | 2 – 30 ppm | Emphasizes the smell of beer. In excess, it can give a tart bitterness. Beer with a magnesium content above 125 ppm has a diuretic and laxative effect. | It has an important effect on the work of some enzymes. Decreases the pH of the wort, but to a lesser extent than calcium. | Nutrient medium for yeast. |
FAQ
The two most important minerals in brewing water are calcium and magnesium. Other minerals that can be present in brewing water include Sodium, Potassium, Sulfates, Phosphate, Chloride, Carbonates, Nitrates and Nitrites, Iron, Copper, Zinc, Manganese.
Water is considered to be hard if it has high mineral content. Water is considered to be soft if it has low mineral content. The hardness of water can impact the flavor, clarity, and overall quality of your beer.
Filtered water has had some of the minerals removed from it while unfiltered water still contains all of the minerals. The type of water you use for brewing can impact the flavor, clarity, and overall quality of your beer.
pH is a measure of how acidic or basic a substance is. The pH of the brewing water can impact the flavor, clarity, and overall quality of your beer. If you need to adjust the pH of your water, you can do so by using acids or bases.
Distilled water is free from all minerals and impurities. It can be used for brewing, but it’s important to add minerals back into the water to ensure that your beer has the proper flavor and quality.
