4.2.3 Lime Softening

Lime softening is another option for hardness reduction in water with high Temporary Hardness. This softening is typically conducted using either an Excess Lime or Split-Treatment process. These processes affect only the calcium, magnesium, and bicarbonate concentrations while leaving the water's other ion concentrations unchanged.

When both calcium and magnesium concentration in tap water are excessive, the Excess Lime process is recommended. The Excess Lime procedure is recommended when the water's magnesium content is greater than about 15 ppm. In the Excess Lime process, pickling lime (calcium hydroxide) is added to the raw water to elevate its pH above 11. The high pH causes both calcium and magnesium compounds to precipitate out of the water. After the water clears, the water is immediately decanted off the sediment. When properly performed, Excess Lime softened water provides moderately-hard water with typical concentrations as low as 12 ppm calcium and 3 ppm magnesium in water with a high Temporary Hardness (low chloride and sulfate concentrations). When the water also contains significant Permanent Hardness (hardness associated with chloride and sulfate), lime softening is not as effective and the final calcium and magnesium concentrations will be higher than indicated here.

When the starting water has high Temporary Hardness and low magnesium concentration, the Excess Lime softening procedure above is modified to a Split-Treatment process that requires the pH be raised to only 10 instead of 11. This lower pH target still causes calcium to precipitate without affecting the magnesium content. The lower pH of the decanted water is easier to neutralize through aeration or acidification with this approach. When properly performed in water with a high Temporary Hardness (low chloride and sulfate concentrations), this process reduces calcium concentration to as low as 12 ppm calcium. The magnesium concentration is unchanged. When the water also contains significant Permanent Hardness (hardness associated with chloride and sulfate), lime softening is not as effective and the final calcium concentration will be higher than indicated here. Immediately after the water clears and the sediment has dropped, the water is decanted off the sediment. Since good brewing practice is to use brewing water with calcium concentration of at least 40 to 50 ppm, the Split-Treatment process includes blending a portion of the raw water with the decanted, lime-treated water to bring the calcium concentration back up to desirable level. This blending also reduces the high pH of the lime-treated water which makes it easier to bring the pH of the blended water down.

Since the water pH and alkalinity are high after treatment in either of the processes above, the pH and alkalinity must be reduced prior to brewing usage. Aeration (to dissolve CO2 in the water) and/or the addition of acid are suitable for reducing the pH and alkalinity of the decanted, lime-treated water. Reducing the pH of the lime-softened water to under 8.6 through aeration or acid addition is desirable. The lime-softening methods above require time, special chemicals, and a pH meter to perform successfully.

4.2.4 Ion-Exchange Softening

Ion-Exchange Softening is a common household water softening method that uses salt (sodium chloride or potassium chloride) to soften water. Water softened with this process should not typically be used for brewing water since the hardness ions (Ca and Mg) are replaced with elevated levels of sodium or potassium that may impart undesirable flavor and potentially harm the yeast. Since calcium and magnesium ions are beneficial to brewing, removing them from the water and replacing them with sodium or potassium is not desirable. Additionally, ion-exchange water softeners do not reduce the alkalinity of the softened water. Since the alkalinity remains high and hardness is reduced in softened water, the RA of the water is raised significantly, making it less suitable for brewing.

While the previous paragraph says not to use ion-exchange softened water for brewing, there are waters that may be ion-exchange softened and still be suitable for brewing. If the water has low hardness and suffers from elevated iron or manganese content, then that water may be acceptably treated with ion-exchange softening to help reduce the iron and manganese while avoiding excessive sodium or potassium content. The metallic perceptions from iron or manganese make the raw water unsuited for brewing. In general, if the sodium or potassium content of the softened water is below 50 ppm, it might be usable for brewing. Calcium can be added to the softened water to improve its brewing performance.

4.3 Alkalinity Adjustment

Alkalinity is the primary factor affecting the performance of the mash. Alkalinity is produced by bicarbonate, carbonate, and hydroxyl in the water. Bicarbonate is the predominant species in the typical municipal water system pH range of 6.5 to 8.5. There are several reasons why bicarbonate is the predominant species in tap water. Carbonate does not exist in significant concentration in that typical water pH range since it is preferentially transformed to bicarbonate. Hydroxyl is a strong base that reacts easily with impurities in the water. Since there are typically impurities in the water, hydroxyl does not exist in significant concentration in drinking water supplies.

Excessive alkalinity can reduce the quality and perception of pale colored beers. Alkalinity can also have a detrimental effect on beers made with Malt Extract since excessive alkalinity can drive up the pH of the reconstituted wort and finished beer. Water used for beers made with Malt Extract should have alkalinity under 50 ppm as CaCO3. The alkalinity of mashing water should be adjusted based on the acidity of the mash grist.

Most brewing requires that mashing water use low alkalinity water and all sparging water should have low alkalinity. Alkalinity can be reduced in a number of ways. Dilution with distilled water or RO water is effective in reducing alkalinity. Acid addition is also a simple way to neutralize alkalinity.

Brewing with acidic grists (significant roast and/or crystal malt content) can require that the mashing water have alkalinity. Alkalinity helps buffer the drop pH created by the acidic grist and helps keep the mash pH in the proper range. Chalk (calcium carbonate), Pickling Lime (calcium hydroxide), or Baking Soda (sodium bicarbonate) can be used to increase alkalinity. As mentioned above, sparging water should have low alkalinity and alkalinity-increasing minerals should not be added to sparging water.

A summary of alkalinity adjustment options are presented in the sections below.

4.3.1 Chalk

Chalk increases alkalinity. Because Chalk does not dissolve easily in plain water, chalk should only be added to the mash. Most acids in the mash are weak and only a small portion of the chalk will be dissolved. To fully dissolve chalk in water, it must be dissolved with an acid. In nature, CO2 forms carbonic acid in water which dissolves the chalk. Bubbling air or CO2 through a chalk water solution can be used to dissolve the chalk, but that requires time and effort.

Evidence has shown that even in the mash, chalk does not dissolve in significant quantity and the chalk’s theoretical amount of alkalinity is not produced in the mash. That evidence shows that the mash pH can only be increased by 0.1 to 0.2 units, no matter how high the chalk dosage is. Other brewing water references and software may assume either all or half of the theoretical alkalinity is added with chalk addition. A brewer should verify the assumption made by those resources for the amount of alkalinity added to the water from a chalk addition. A more comprehensive discussion on the time and pH dependent behavior of chalk is presented by AJ DeLange in the following link: http://wetnewf.org/pdfs/chalk.html (the website is currently non-functioning)

While chalk produces calcium and carbonate ions, the carbonate ions will eventually form bicarbonate ions in water with moderate to low pH. For a chalk addition of 1 gram per gallon, the effective bicarbonate concentration is increased by about 322 ppm assuming the chalk is fully dissolved. Undissolved chalk precipitates from the water and is not an active component of the water chemistry. In general, brewers should avoid using chalk for mashing water alkalinity adjustment since chalk is an unreliable alkalinity contributor. Other more reliable sources of alkalinity are presented below.

4.3.2 Pickling Lime

Pickling Lime (calcium hydroxide) increases alkalinity and is readily soluble in water, but must be handled with care since it can burn skin and eyes and significantly raise the mash pH if not dosed properly. Pickling Lime can often be found where home canning supplies are sold. It is also available at salt-water aquarium shops and may be found under the names: Kalkwasser, Lime, or Slaked Lime. Although pickling lime supplies hydroxyl ions to water, the hydroxyl content can be represented as a corresponding bicarbonate concentration for use in brewing calculations. For a pickling lime addition of 1 gram in a gallon of water, the corresponding increase in “effective” bicarbonate content is about 435 ppm and the calcium increase is about 143 ppm.

A problem with pickling lime is its purity. Pickling lime will degrade into chalk when exposed to moisture in the air. Therefore, pickling lime may not always produce the intended degree of alkalinity. The purity of pickling lime can be easily assessed by placing a drop of acid on a small amount of the dry powder. If the powder bubbles or fizzes, that is a sign that chalk is present in the sample. Pure pickling lime will react with the acid without bubbling or fizzing.

4.3.3 Baking Soda

Baking Soda increases alkalinity and is readily soluble in water, but its usage should be limited if the sodium content of the brewing water is a concern. Sodium at a concentration of 100 ppm or more may produce harshness in the beer flavor. Baking soda is relatively inert and does not degrade. Therefore, its strength (alkalinity) can typically be assumed to be consistent. A baking soda addition of 1 gram per gallon of water, increases the bicarbonate content of the water by about 192 ppm and the sodium content by about 72 ppm. Another way to look at baking soda's contribution is that when added to produce a moderate sodium increase of 40 ppm, the alkalinity of the water increases by over 85 ppm (as CaCO3). That alkalinity increase is often sufficient for brewing many dark beers.

4.3.4 Liquid Organic Acids

Liquid Organic Acids such as Lactic and Acetic Acid can be used for alkalinity reduction and acidification. Soured wort (sauergut) is a traditional German brewing method of producing dilute lactic acid for alkalinity reduction and acidification.

Lactic Acid is readily available for brewing use in many countries, but it can produce a distinctive “tang” in the flavor profile at high concentration. Lactic acid flavor is typically characterized as smooth. It is a weak acid that can be somewhat safer to handle than other stronger acids. Lactic acid is reported to have a flavor threshold of about 400 ppm in beer (Briggs et al., 1981). The flavor threshold can vary between tasters. Therefore, the 400 ppm threshold may not hold for all individuals. In addition, typical beers (especially German beers) naturally have a low concentration of lactic acid (typically 50 to 300 ppm) from malting, fermentation, sauergut usage, and production by-products (Briggs et al., 1981). Therefore, it may not be possible to use lactic acid to treat highly alkaline water without flavor impact. Lactic acid is a monoprotic acid and it consumes 1 part bicarbonate per one part lactic acid. For these reasons, it appears that the maximum alkalinity neutralization that lactic acid could provide for brewing is about 100 to 350 ppm reduction in bicarbonate (82 to 287 ppm alkalinity reduction, as CaCO3) in the water. In general, 1 ml of 88% lactic acid per gallon of water (0.37ml per liter) should avoid incurring lactic taste effects in brewing.

Lactic acid is quite stable and does not degrade appreciably when stored at room temperature in sealed containers. The shelf life of lactic acid stored at 80°C (176°F) is reported at over 80 years. However, lactic acid is hygroscopic and will absorb moisture from the air which decreases the acid’s concentration. Keep lactic acid in a sealed container to reduce air contact and loss of strength.

Acetic Acid produces a very strong, pungent, and distinctive flavor and aroma (vinegar) and it is not typically used in brewing. However, there are some beer styles that display acetic notes that can benefit from minor acetic acid additions instead of relying on natural processes to create those flavors. In addition, controlled addition of acetic acid can be more reliable and repeatable than culturing acetic bacteria in beer. Allowing acetic bacteria into the brewery environment may introduce a potential beer spoiler into the brewery.

Sauergut is produced in the brewery by inoculating fresh wort with lactic bacteria and fermenting it without oxygen contact (anaerobic) at around 118°F (48°C). It generally has to be used fresh and must be recently produced to be effective. The resulting saurergut is added directly to the mash tun and to the kettle to reduce alkalinity and pH. The lactic acid concentration of the sauergut typically varies between 0.5 and 1.5 percent. An additional resource on sauergut production is provided here.

4.3.5 Phosphoric Acid

Phosphoric Acid can be used for alkalinity reduction in brewing water and it has little flavor effect since this acid is similar to the malt acids produced during mashing. Malt adds about 1 percent phosphatic compounds to wort, although many of them are bound in organic molecules such as phytin. Phosphoric acid can complex with high calcium concentration in water and precipitate from solution. However when water’s calcium concentration is less than about 300 ppm, adding phosphoric acid for alkalinity neutralization (typically added at well under 0.1 percent) should not cause excessive precipitation of calcium in the mash and can be used freely in brewing. Phosphoric acid has less tendency to create acidic vapors than hydrochloric and sulfuric acids, but it is a strong acid that must be handled carefully when used at high strength.

4.3.6 Hydrochloric and Sulfuric Acids

Hydrochloric and Sulfuric acids are strong acids that reduce alkalinity and also contribute chloride or sulfate ions, respectively. These acids do not produce strong flavor impacts, but the limitations for either chloride or sulfate concentration mentioned above should be observed. Even at low strength, these acids may create hazardous acidic vapors that will corrode metal and damage lungs, eyes, and skin. For typical brewing usage, diluting these acids to lower strength or concentration is recommended for safety.

CRS is a proprietary blend of hydrochloric and sulfuric acids, most commonly available in the United Kingdom. When dosed at 1 ml per liter, it adds a fixed ratio of 64 ppm chloride and 87 ppm sulfate while neutralizing 221 ppm bicarbonate (181 ppm alkalinity reduction, as CaCO3).

4.3.7 Solid Organic Acids

Solid Organic Acids such as Citric, Malic, and Tartaric acids can also be utilized for alkalinity reduction and acidification. These acids may impart distinctive flavor into the water and beer if used at elevated concentration. In some cases, those flavors may be welcome in beer. These organic acids can add fruity or estery perceptions to the beer that may benefit certain styles.

Citric Acid is reported to have a flavor threshold of about 150 ppm in beer (Briggs et al., 1981). The flavor threshold can vary between tasters. Therefore, the 150 ppm threshold may not hold for all individuals. In addition, typical beers naturally have a low concentration of citric acid (typically 50 to 250 ppm) from malting and fermentation by-products (Briggs et al., 1981). Therefore, it may not be possible to exceed 150 ppm of citric acid in water, without flavor impact.

4.3.8 Acid Safety

A concern with acids is that they can be hazardous to handle and they require knowledge or experience to determine how much is needed. Accurate measurement for acid addition is also needed. Graduated pipettes, graduated cylinders, and graduated medicine droppers are suitable for measuring liquid acids. Accurate scales are required for measuring solid acids.

4.3.9 Acid Malt

Acid Malt can also be used to reduce alkalinity. Acid malt is similar to an acid addition since the malt has been infused with lactic acid or been acidified by bacterial action. The typical acid content of acid malt can vary from maltster to maltster. A range of 2 to 3 percent by weight lactic acid to acidulated grain weight is typical. Brewers should monitor their mashing pH results to assess if the strength of their acid malt supply has varied from typical and adjust the dosage for future uses.

Since the primary acid is lactic, the acid flavor is relatively smooth, but other components from the acidification process may provide more complex flavor than refined lactic acid. Since acid malt is typically added as a low percentage of the overall grist, lighter and less flavored beers should benefit more from the complex flavor offered by acid malt. Stronger and bolder flavored beers are less likely to benefit from the acid malt’s flavor contribution.

4.3.10 Harden Water to Increase Malt Acid

Hardening the brewing water to increase malt acid (phytin) production is a common alternative for alkalinity reduction. The brewing water is hardened with calcium and/or magnesium salts to create more malt acids through the malt phosphate reaction with the calcium or magnesium (hardness) ions. This approach is directly from the concept of Residual Alkalinity presented above.

Hardening an alkaline water does not make the water suitable for sparging use. The malt phytin content is depleted during sparging and that malt acid production is limited during sparging. Alkaline sparging water should be neutralized with an acid addition.

4.3.11 Decarbonation by Boiling

Water with high Temporary Hardness is suited for hardness and alkalinity reduction by boiling. An extended discussion of this method is presented in the Hardness Adjustment section above.

4.3.12 Lime Softening

Lime Softening is another decarbonation practice where the water is chemically reacted with a strong base to force the less soluble calcium carbonate and magnesium hydroxide to precipitate out of the water due to high pH. When conducted properly, lime softening reduces alkalinity. Lime softening is presented with more detail in the Hardness Adjustment section.

4.3.13 Delaying Hardness Mineral Additions to the Mash

Delaying hardness mineral additions to the mash may be an alternative to adding alkalinity when mashing an acidic grist. When the brewing water has lower than desired alkalinity and calcium and/or magnesium additions are planned for the water, delaying the addition of those hardness-producing minerals to the mash can be employed to avoid decreasing RA and mashing pH any further. An overly low mashing pH can increase the proteolysis of proteins in the wort and the body of the resulting wort can have less body (be thinner) than desired. Proper mashing pH avoids excessive proteolysis which should retain more of the medium-length proteins that contribute to beer body.

Although calcium and magnesium minerals can be important additions to brewing water, they are not absolutely needed in the mash when the alkalinity is too low for the mash. As long as those minerals are added to the wort prior to fermentation, they will still serve their purpose as if originally added to the mash without the detriment of decreasing mash pH too far. The calcium and/or magnesium additions intended for the mash can be added directly the kettle prior to the boil to provide the desired water profile to the wort. Be aware that the pH reducing effect of hardness mineral addition is not avoided, it is only delayed past the mash and it occurs in the kettle. If the resulting kettle wort pH will be too low, it is better to use the proper alkalinity level in the mash to avoid this effect.

4.3.14 Altering Mash Thickness

Since mash pH hinges on the relative amounts of acidity from the grist and alkalinity from the water, altering the relative amount of water in the mash does affect mash pH. In the case of mashing with a water with higher than desired alkalinity, reducing the amount of water in the mash (water/grist ratio) can have the net effect of reducing the mash pH. If the mashing water has too little alkalinity, increasing the amount of water in the mash can have the effect of increasing the mash pH.

Mashing trials have proven that mash thickness also has an effect on the variation of wort pH during the mash. Thin mashes tend to have a greater variation in pH during the course of the mash than thick mashes do. The popularity of Brew in a Bag (BIAB) methods has increased the use of thin mashes in brewing. Brewers should be aware that the pH does vary throughout the typical mashing period and pH tends to become relatively constant after about 45 minutes of mashing. The fineness of the grist milling is expected to have an influence in the speed at which the mashing pH becomes stable, (finer = quicker).

4.3.15 When to Add Acid to Mashing and Sparging Water

If the raw water has significant alkalinity, it does make a difference if an acid dose is added to cold or hot water. The alkalinity value reported for raw water is typically measured near room temperature. As pointed out above, raising the temperature of water reduces the solubility of dissolved carbon dioxide in the water. Heating decarbonates the water and converts alkalinity in the water (mainly bicarbonate) to undissolved chalk in the water and the carbon dioxide bubbles out of the water. Therefore, the alkalinity of heated water is reduced in comparison to its room-temperature alkalinity.

Since acid additions are calculated based on that reported room-temperature alkalinity value, it is important that any acid dose calculated for that water be added prior to heating the water. If the acid is added after the water is heated, the reduced alkalinity of the heated water can mean that too much acid will be added and the resulting brewing water alkalinity will be lower than targeted. Add acid to brewing water prior to heating in order to achieve the alkalinity targeted by brewing water calculations. If acid must be added after the water has been heated, test the alkalinity of the heated water and use that new alkalinity to calculate the acid addition.

If the raw water has very low alkalinity (such as distilled or RO water), there is little difference in alkalinity caused by heating the water and acid doses can be added to hot or cold water with near equal effect.

4.4 Mineral Profile Adjustment

Mineral additions are sometimes desirable for RA adjustment and for creating certain flavor contributions in the finished beer. Common mineral salts are typically used to provide the mineral additions. The following mineral salts are commonly used in brewing water adjustment. Only food-grade minerals should be used for water adjustment.

Gypsum provides calcium and sulfate ions to brewing water. Although gypsum has limited solubility in water, it is readily soluble in water at the concentrations typically used for brewing. The solubility limit for gypsum in boiling water is about 1.6 grams per liter of water. That dosing rate would approach 400 ppm calcium and 900 ppm sulfate which is far higher than recommended for brewing water. Therefore, gypsum can be considered readily soluble at typical brewing water usage rates. Gypsum is more soluble in cool to warm water (maximum gypsum solubility occurs at around 40C or 100F) and should be added to water prior to boiling for quicker dissolution. Vigorous stirring is typically required to speed the gypsum dissolution. If gypsum does not dissolve in a timely manner when added to water at less than 1.6 grams per liter, test the gypsum for the presence of chalk by adding an acid such as vinegar or lactic to the dry powder. If the mixture 'fizzes', the gypsum is adulterated with chalk. Gypsum is also known by its chemical name: calcium sulfate dihydrate and its chemical formula is: CaSO4·2H2O. Gypsum does not readily pick up moisture from the air. Gypsum is typically available from brewing supply stores. A gypsum addition of 1 gram per gallon, increases the calcium content of the water by about 61 ppm and the sulfate content by about 147 ppm. An addition of 1 gram per liter, increases the calcium content of the water by about 232 ppm and the sulfate content by about 558 ppm.

Calcium Chloride provides calcium and chloride ions and is readily soluble in water. Calcium chloride is highly hygroscopic and will rapidly draw moisture out of the air, changing its state of hydration. A common form of Calcium Chloride as a brewing mineral is calcium chloride dihydrate and its chemical formula is: CaCl2·2H2O. A brewer may also obtain this mineral in anhydrous, monohydrate, and tetrahydrate forms. Testing of typical solid calcium chloride sold by US homebrewing stores, shows that the mineral often has a hydration state between anhydrous and dihydrate. Assuming the mineral is in its anhydrous state helps avoid overdosing wort with chloride.

If this mineral is not kept in a tightly sealed container, it will eventually become a saturated mass and the reliability of mineral addition calculations will be poor. In its dihydrate form, a calcium chloride addition of 1 gram per gallon, increases the calcium content of the water by about 72 ppm and the chloride content by about 127 ppm. An addition of 1 gram per liter, increases the calcium content of the water by about 272 ppm and the chloride content by about 483 ppm. Contrast those results with those for the anhydrous mineral where 1 gram per gallon adds 95 ppm calcium and 169 ppm chloride.

An alternative to solid calcium chloride dosing is to utilize liquid calcium chloride solution. These solutions can be prepared in the brewery or purchased as food-grade solutions. Since the specific gravity of calcium chloride solutions vary directly with the percentage of calcium chloride in solution, the strength of the solutions can be assessed by hydrometer or volumetric measurement. Using liquid solutions does avoid the problem of hydration change noted above for solid calcium chloride.

Epsom Salt provides magnesium and sulfate ions and is readily soluble in water. Epsom salt is also known by its chemical name: magnesium sulfate heptahydrate and its chemical formula is: MgSO4·7H2O. Epsom Salt does not readily pick up moisture from the air. Epsom salt is typically available from drug stores. Be sure to obtain pure, food-grade Epsom Salt. An Epsom salt addition of 1 gram per gallon, increases the magnesium content of the water by about 26 ppm and the sulfate content by about 103 ppm. An addition of 1 gram per liter, increases the magnesium content of the water by about 99 ppm and the sulfate content by about 389 ppm.

Magnesium Chloride provides magnesium and chloride ions and is readily soluble in water. A common form of magnesium chloride as a brewing mineral is magnesium chloride hexahydrate and its chemical formula is: MgCl2·6H2O. Magnesium chloride is highly hygroscopic and will rapidly draw moisture out of the air, changing its state of hydration. It should be kept in a tightly sealed container. Magnesium chloride is typically used as a health supplement and may be found in health food or drug stores. A magnesium chloride addition of 1 gram per gallon, increases the magnesium content of the water by about 32 ppm and the chloride content by about 92 ppm. An addition of 1 gram per liter, increases the magnesium content of the water by about 120 ppm and the chloride content by about 349 ppm.

Table Salt provides sodium and chloride ions and is readily soluble in water. Non-iodized salt is preferred since iodine is poisonous to yeast. Table salt is also known as sodium chloride and its chemical formula is: NaCl. Table salt does not readily pick up moisture from the air. Non-iodized table salt is available from grocery stores. A table salt addition of 1 gram per gallon, increases the sodium content of the water by about 104 ppm and the chloride content by about 160 ppm. An addition of 1 gram per liter, increases the sodium content of the water by about 393 ppm and the chloride content by about 607 ppm.

Baking Soda provides sodium and bicarbonate ions and is readily soluble in water. Baking soda is also known as sodium bicarbonate and its chemical formula is: NaHCO3. Baking soda does not readily pick up moisture from the air. Baking soda is available from grocery stores. A baking soda addition of 1 gram per gallon, increases the sodium content of the water by about 72 ppm and the bicarbonate content by about 192 ppm. An addition of 1 gram per liter, increases the sodium content of the water by about 274 ppm and the bicarbonate content by about 726 ppm.

Chalk provides calcium and carbonate ions. Chalk is also known as Limestone and calcium carbonate and its chemical formula is: CaCO3. Chalk does not readily pick up moisture from the air. Chalk is typically available from brewing supply stores.

Chalk is not readily soluble in water and acidic conditions are required to fully dissolve chalk into water. In nature, carbon dioxide dissolves into water to form carbonic acid. Carbonic acid dissolves chalk into the water and converts all the carbonate into bicarbonate. Aerating (bubbling, splashing, spraying, etc) helps add carbon dioxide to water, but that process can take days. The process can be accelerated by pressurizing the water with carbon dioxide (carbonation) to dissolve chalk. The fully alkalinity of chalk can only be achieved when the chalk is fully dissolved in water. If chalk cannot be fully dissolved into the water prior to brewing, adding chalk to the mash can help partially dissolve the chalk. The mash contains only a small amount of acids strong enough to dissolve chalk quickly and the mashing pH will typically only drop by about 0.1 units, without regard to how much chalk is added. Therefore, chalk use is not recommended in typical brewery usage.

A chalk addition of 1 gram per gallon, increases the calcium content of the water by about 106 ppm (53 ppm) and the bicarbonate content by about 322 ppm (161 ppm) if the chalk is fully dissolved (partially dissolved concentrations in parentheses). An addition of 1 gram per liter, increases the calcium content of the water by about 400 ppm (200 ppm) and the bicarbonate content by about 1220 ppm (610 ppm).

Pickling Lime provides calcium and hydroxide ions. Pickling Lime is also known as Slaked Lime and calcium hydroxide. Its chemical formula is: Ca(OH)2. The hydroxide ions are strong consumers of acidity and can significantly increase pH if over dosed. Consuming acidity is the definition of Alkalinity. Therefore, an equivalent bicarbonate alkalinity contribution can be calculated. Pickling Lime is readily soluble in water and must be used with care.

Pickling Lime will pick up moisture from the air which allows the mineral to revert to Chalk with enough time and CO2 contact. Pickling Lime should be kept in a tightly sealed container to avoid air contact. Pickling Lime can typically be found in stores selling home canning supplies which may include grocery stores. The purity of pickling lime can be assessed by dropping strong acid (acetic, lactic, phosphoric, etc) on a dry sample of the lime. If the sample bubbles, there is chalk impurity in the lime.

A pure pickling lime addition of 1 gram per gallon, increases the calcium content of the water by about 143 ppm and the effective bicarbonate content by about 435 ppm. An addition of 1 gram per liter, increases the calcium content of the water by about 541 ppm and the effective bicarbonate content by about 1645 ppm.

Sulfate/Chloride Ratio can be a helpful insight into how the combination of these ions may be perceived in beer taste. The ratio was presented in the Handbook of Brewing (Priest & Stewart) as Chloride/Sulfate Ratio. Since chloride is more typically preferred at lower concentrations than sulfate in English and American Ales, reversing the original ratio produces a value greater than one in those cases. The ratio is presented here in the Sulfate/Chloride format for that reason.

At moderate concentrations, the Sulfate/Chloride Ratio provides a rough indicator of how the brewing water can shift the perception of Sweetness/Maltiness or Bitterness/Dryness in the finished beer. Briggs et. al. describes the ratio's effect as Fullness versus Dryness and those terms more accurately describe the effects better than the terms: Maltiness or Bitterness. Chloride accentuates fullness and sulfate accentuates dryness. The fullness presented by the chloride enhances the perception of sweetness and maltiness while the dryness from sulfate enhances the perception of bitterness. The ratio of these ions can shift flavor perceptions of the finished beer. Brewers should be aware that these ion effects can only improve perceptions. These ions or their perceptions will not alter the actual levels of bittering or sweetness in the finished beer.

Since flavor contributions and perceptions from these ions disappear at very low concentrations, the ratio provides little indication when the chloride level is less than about 25 ppm. Conversely, at very high concentrations, the ions' impacts can overwhelm the beer and produce an excessively minerally flavor in the beer. Therefore, the ratio should be limited to chloride concentration of about 100 ppm or less. Within these limitations on the ratio, the following flavor perceptions are taken from the Handbook of Brewing.