Beer-like beverages were made in ancient times as soon as a group of people had learnt to use a cereal for food. Cereals containing some sugars can go through spontaneous fermentation because of wild yeasts in the air around us. Evidence of beer was found in ancient pottery jars that were estimated to be 7000 years old. In South Africa (SA), sorghum and maize beers were brewed by Sotho, Zulu and Xhosa people.
In earlier times, beer was often safer to drink than water, as the brewing process would destroy most bacteria. Today, we use clean water to make beer. The minerals in the water have a major impact on the flavour of the beer. Differences in beer around the world is often due to the profile of the water found in different areas.
Then there is also the water used in the production of beer … In a recent article by the World Wide Fund for Nature (WWF) SA on their water focused partnership with SABMiller, they say “it takes 4.5 liters of water to brew 1 liter of beer.” When you include the water used to grow the cereal (hops) for the beer, the total water footprint for beer in SA is 155 liters of water / liter of beer! This is another reason to monitor the profile of the water – in order treat the water for reuse.
Characterizing Water according to BrewWiki.comBrewing water is usually categorized using a profile of Calcium (Ca), Sulfate (SO4), Sodium (Na), Chloride (Cl), Carbonate (CO3) and Magnesium (Mg) ions. In addition, the overall alkalinity (carbonates and Bi carbonates) becomes important when mashing for pH control in all-grain brews.
The principal ions are:
- Calcium (Ca) – Aids in mashing and yeast growth if used in moderation. Should be kept to the 80-100 ppm range for mashing and sparging. Ca is the major ion responsible for mash acidification. The process is calcium ions react with phosphates in malt creating calcium phosphate and hydrogen ions. An increase in Hydrogen ion concentration reduces pH and is buffered by the presence of Bicarbonates and carbonates therefore sufficient calcium ions need to be present to overcome the buffering to reduce pH to correct mash pH of 5.2 to 5.6.
- Sulfate (SO4) – in the form of Calcium Sulphate for adding calcium if the water is deficient in sulfate and is used to add sulfate “crispness” to hop bitterness.
- Sodium (Na) – Helps to accentuate sweetness of malt at levels below 100 ppm. Generally should be kept to a low to moderate level as high levels are associated with sour, salty tastes.
- Chloride (Cl) – Accentuated flavor of beer when kept below 100 ppm for light beers or a max of 300 ppm for dark beers. Can result in bleach or medicine flavor if raised too high.
- Carbonate / Bicarbonate (HCO3) – An alkaline buffering agent that raises the pH of the mash, reducing acidity. Contributes to bitterness, darker color and extraction of tannins during the mash.
- Magnesium (Mg) – Secondary source of hardness. Needed in small amounts (10-30 ppm) for yeast growth and better beer flavor. Overuse (anything > 50) can create astringency.
Water and Beer Styles
The most famous styles for a given city are typically closely tied to the water available. For example, the famous Pilsner style originated in the city of Pilsen, Czech Republic. Their soft water has very low levels of all minerals, which aids in producing a pale color lager with clean bitterness. Similarly the high levels of calcium, carbonate and sulfate of Burton on Trent’s hard water in the UK help produce unique hoppy English pale ales. For examples of some brewing waters from around the world, see the hops table in the external links below.
German Brewers of old employed an acid rest to acidify the mash, as, due to insufficient calcium ions in the low mineral content water, the mash would not reach the desired pH. The acid rest allowed enzymatic phytase activity and in no small part bacterial activity and growth to acidify mash. The low mineral content water in Dublin was overcome by the addition of highly roasted acid malts and of course made beer quite dark!. Burton water that is high in calcium ions meant that an acid rest was not needed and a single infusion mash is all that was required. Malting technology in the past meant that a percentage of the kilned malt was burnt producing the acidity required such malt was also often poorly modified. Better technology lead to lighter kilned malts great for light lager, but required an acid rest in low calcium waters.
Water adjusting goals
When thinking of water chemistry for brewing there are 2 separate considerations. Firstly, and most importantly, that the dissolved ion profile (mostly Ca ions) be conducive to attaining the correct mash pH in the range of 5.2-5.6. Secondly that dissolved ion concentrations A. Not have a negative flavour impact and B. Where required have a positive or desired flavour contribution. It is no point obsessing over the optimal Sulphate to Chloride ion ratio if excessive tannins are extracted due to a high pH mash!
You can add minerals to your water to adjust the alkalinity for mashing and also to add minerals for flavor complexity. The most popular additives are Calcium sulphate (CaSO4) commonly gypsum flour, Calcium carbonate (CaCO3) chalk powder, Calcium Chloride (CaCl), Sodium Chloride (NaCl) salt the non iodised type, Sodium bicarbonate (NaHCO3) Baking Soda and Magnesium sulphate (MgSO4) or epsom salts. Carbonates can be used to reduce or buffer the alkalinity of the mash. Brewing software or a water calculation tool can help you determine the correct amount of additives to use. It should be noted that calcium carbonate is very insoluble in water.
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