Water requirements when brewing beer

The quality of brewing water affects the enzyme activity in mash, solubility of minerals, taste and quality of beer, and the condition of brewing equipment. To achieve the great taste of beer and ascertain the cleanliness of equipment after cleaning process, water quality check must be carried out in the various stages of brewing process with reliable and accurate instruments. Having the advantages of less maintenance design, low-volume sample requirement, and hassle-free operation, ；liquor handheld meters and electrodes are recommended for home and commercial beer brewers.

Introduction

Beer is one of the most widely consumed alcoholic drinks and the third most popular drink overall (after water and tea) in the world. It has become a part of the culture of many nations and often associated with social traditions such as festivals and games.

Brewing is the process of making beer. The four main ingredients of beer are cereal grains (e.g., malted barley, wheat, maize, rice) as starch source, water, flavoring agents (e.g., hops, gruit, herbs, fruits), and yeast. Malted barley and hops are the most commonly used cereal grain and flavoring agent, respectively. In beer brewing, the starch source is mixed with water and converted into a sugary liquid called wort. The wort is subsequently converted into the alcoholic drink by fermentation using yeast.

As beer is mostly water, the composition of brewing water can affect the quality of beer. Brewing water should be clean and odorless. Water can come from two sources—surface water and groundwater. The former is low in dissolved minerals but higher in organic matter while the latter is generally higher in dissolved minerals and low in organic matter. To determine the mineral composition of water, beer brewers can ask reports from local water companies, send sample water to laboratories, or perform the tests by themselves using proper equipment. The common test parameters are explained below. Based on the results, brewers can make necessary water adjustments to make a great beer.

As water quality check in beer brewing process is a crucial step to achieve exceptional taste and quality of beer, the twin pocket meters and dissolved oxygen handheld meters and dissolved oxygen electrodes are recommended for beer brewers. Aside from their simple and easy operation, the pocket meters have unique flat sensors that can measure sample as low as 0.05 ml in just few seconds. The handheld meters are packaged with electrodes, which have innovative replaceable tips and built-in temperature sensor, in carrying cases for routine measurements in the field.

Water Hardness

Water hardness is defined as the amount of dissolved calcium and magnesium in the water. Calcium is the principal ion that determines water hardness. It can overcome the buffering capacity of malt phosphates, lower the mash pH to acceptable range3 and promote clarity, flavor, and stability in the finished beer. The ideal calcium concentration in the brewing water is between 50 and 150 ppm.3 Calcium sulfate, also known as gypsum, or calcium chloride (CaCl2) can be added to increase the amount of calcium ions in water. Magnesium also contributes to water hardness and therefore affects the mash pH, but to a lesser extent than the calcium.

Alkalinity

Alkalinity is the capacity of water to resist changes in pH that would make the water more acidic. It is a measurement of the concentration of all alkaline substances dissolved in the water such as carbonates and bicarbonates which buffer pH in the water by neutralizing acids.

Calcium concentrations must be balanced with low carbonate-bicarbonate levels as they have countering effect on calcium. These ions should be kept to less than 50ppm. Bicarbonates, being strong alkaline buffers, may raise the pH of the mash to unacceptable levels, if available in large amounts.

pH

pH is important in various stages of beer brewing—mash, wort, and finished beer. Most municipal water sources are slightly alkaline. When water is combined with grains in a mash tun, the pH of the mixture, called mash, drops compared to the pH of water alone. The mineral composition (i.e., calcium, magnesium, carbonates, and bicarbonate) of the water and natural acidification process in mashing of malted grains drive the mash pH.  The ideal mash pH range is 5.2 to 5.5 with preference to the lower end (5.2) for improved enzyme activity leading to optimal conversion of starches to liquid sugars called wort. After mashing, the wort is drained and the grains are washed. This process is called sparging. As sparging progresses, the pH of wort being run off from the mash increases. The pH of the run off wort should be below 6 because higher pH will extract tannins, silicates, and other compounds from the grain leading to astringent-off flavors and cloudy, hazy beer.

The collected wort is transferred to a kettle for boiling. During the boil, calcium phosphate is still precipitated (as long as calcium is still present) and the pH decreases, just like during mashing. A post-boil wort pH of 5.0 to 5.2 should be achieved. This pH range will help extract the best character from hops, maximize the amount of hop break formed, and keep color pick-up to a minimum. Another important function of boiling is coagulating the hot break. The optimal pH for break formation is 5.2. If big, fluffy bits of break material in wort are present in early boiling, it is a confirmation that pH is in the right range. Hot break must be removed so that the hot wort can be clear.

When yeast is added to the wort, the fermentation begins—sugar turns into alcohol and carbon dioxide. During fermentation, the pH continues to drop because yeast takes in ammonium ions (strongly basic) and excretes organic acids (includes lactic acid). The yeast strain chosen can affect the final beer pH—most lager beers = pH 4.2 – 4.6, some ales = pH 3.8, sour beers = around pH 3.0. An optimal pH of less than 4.4 favors faster beer maturation, better beer clarity, better biological stability and more refined beer taste.