Section 3 – Brewing All-Grain Beer
Chapter 15 - Understanding the Mash pH
What Kind of Water Do I Need?
“What kind of water do I need for all-grain brewing?” (you ask)Usually, the water should be of medium hardness and low-to-medium alkalinity, but it depends... “What do these terms mean? Depends on What?”“Where can I get this kind of water?”“What is my own water like?”
This chapter is all about answering those questions. The answers will depend on what type of beer you want to brew and the mineral character of the water that you have to start with. The term “hardness” refers to the amount of calcium and magnesium ions in the water. Hard water commonly causes scale on pipes. Water hardness is often overmatched by water alkalinity. Alkaline water is high in bicarbonates. Water that has high alkalinity causes the mash pH to be higher than it would be normally. Using dark roasted malts in the mash can neutralize alkaline water to achieve the proper mash pH, and this concept will be explored throughout this chapter.
But remember, enzyme activity in the mash is most dependent on temperature, not pH. We are concerned with mash pH to make sure we are in the right ballpark, not to specify how close we are playing to the bag. Our goal is to prevent tannin extraction and enzyme impairment due to being in the wrong ballpark. And this goal is fairly easy to achieve.
How to Read A Water Report
To understand your water, you need to get a copy of your area’s annual water analysis. Call the Public Works department at City Hall and ask for a copy, they will usually send you one free-of-charge. An example for Los Angeles is shown in Table 19. Water quality reports are primarily oriented to the safe drinking water laws regarding contaminants like pesticides, bacteria and toxic metals. As brewers, we are interested in the Secondary or Aesthetic Standards that have to do with taste and pH. In some states, particularly in the west, the source of the water supply can change seasonally, and can often have a big difference in brewing character.
There are several important ions to consider when evaluating brewing water. An ion is an atom or group of atoms that has a net positive or negative charge, due to the loss or gain of an electron. In our discussion of brewing water, the ions are the anion (negative) and cation (positive) components of the minerals dissolved in the water.
The principal ions that affect pH are Calcium (Ca+2), Magnesium (Mg+2), and Bicarbonate (HCO3-1). The other three principal ions: Sodium (Na+1), Chloride (Cl-1) and Sulfate (SO4-2), can influence the taste of the water and beer, but do not affect the mash pH like the others. Ion concentrations in water are usually discussed as parts per million (ppm), which is equivalent to a milligram of a substance per liter of water (mg/l).
Descriptions of these ions follow.
Calcium (Ca+2)Atomic Weight = 40.0Equivalent Weight = 20.0Brewing Range = 50-150 ppm.Calcium is the principal ion that determines water hardness and has a +2 charge. As it is in our own bodies, calcium is instrumental to many yeast, enzyme, and protein reactions, both in the mash and in the boil. It promotes clarity, flavor, and stability in the finished beer. Calcium additions may be necessary to assure sufficient enzyme activity for some mashes in water that is low in calcium. Calcium that is matched by bicarbonates in water is referred to as “temporary hardness”. Temporary hardness can be removed by boiling (see Bicarbonate). Calcium that is left behind after the temporary hardness has been removed is called “permanent hardness”.
Magnesium (Mg+2) Atomic Weight = 24.3Equivalent Weight = 12.1Brewing Range = 10-30 ppm.This ion behaves very similarly to Calcium in water, but is less efficacious. It also contributes to water hardness. Magnesium is an important yeast nutrient in small amounts (10–30 ppm), but amounts greater than 50 ppm tend to give a sour-bitter taste to the beer. Levels higher than 125 ppm have a laxative and diuretic affect.
Bicarbonate (HCO3-1) Molecular Weight = 61.0 Equivalent Weight = 61.0 Brewing Range = 0-50 ppm for pale, base-malt only beers. 50-150 ppm for amber colored, toasted malt beers. 150-250 ppm for dark, roasted malt beers. The carbonate family of ions is the big player in determining brewing water chemistry. Carbonate (CO3-2), is an alkaline ion, raising the pH, and neutralizing dark malt acidity. Its cousin, bicarbonate (HCO3-1), has half the buffering capability but actually dominates the chemistry of most brewing water supplies because it is the principal form for carbonates in water with a pH less than 8.4. Carbonate itself typically exists as less than 1% of the total carbonate/bicarbonate/carbonic acid species until the pH exceeds 8.4. There are two methods the homebrewer can use to bring the bicarbonate level down to the nominal 50-150 ppm range for most pale ales, or even lower for light lagers such as Pilsener. These methods are dilution and acidification. Carbonate can be precipitated (ppt) out as Calcium Carbonate (CaCO3) by aeration and boiling, as described in Chapter 4, according to the following reaction: 2HCO3-1 + Ca+2 ‹ CaCO3 (ppt) + H2O + CO2 gas where oxygen from aeration can act as a catalyst and the heat of boiling prevents the carbon dioxide from dissolving back into the water to create carbonic acid. The limitation of this method is that only the temporary hardness will be removed, and not even all of that. About one milliequivalent (50 ppm) of dissolved calcium carbonate will remain in solution, due to its solubility constant. Temporary hardness is the lesser of either the Total Alkalinity as CaCO3 or the Total Hardness as CaCO3, because the “temporary” aspect is actually the neutralization and precipitation of the calcium and bicarbonate. If the total hardness exceeds the total alkalinity, then nearly all of the alkalinity can be removed, down to the 50 ppm limit. If the total alkalinity as CaCO3 exceeds the total hardness (as it often does), then only part of the alkalinity, and nearly all of the calcium will be precipitated, which is not a good situation. You will probably want to add more calcium to the water to equalize the alkalinity. However, dark beer styles depend on having more alkaline water to achieve the right mash pH. This will be discussed in the sections to follow. Dilution is the easiest method of producing low carbonate water. Use distilled water from the grocery store (often referred to as Purified Water for use in steam irons) in a 1:1 ratio, and you will effectively cut your bicarbonate levels in half, although there will be a minor difference due to buffering reactions. Bottom Line—if you want to make soft water from hard water (e.g. to brew a Pilsener), dilution with distilled water is the easiest route. Acidifying the water to neutralize the bicarbonate and turn it into dissolved carbon dioxide is easy to do. There are several brewing software programs available, such as BeerSmith and Bru ‘N Water, that can calculate how many milliliters to add to your water volume to do the job. Sulfate (SO4-2) Molecular Weight = 96.0 Equivalent Weight = 48.0 Brewing Range = 50-150 ppm for normally bitter beers. 150-350 ppm for very bitter beers The sulfate ion also combines with Ca and Mg to contribute to permanent hardness. It accentuates hop bitterness, making the bitterness seem drier and more crisp. At concentrations over 400 ppm however, the resulting bitterness can become astringent and unpleasant, and at concentrations over 750 ppm, it can cause diarrhea. Sulfate is only weakly alkaline and does not contribute to the overall alkalinity of water. Sodium (Na+1) Atomic Weight = 22.9 Equivalent Weight = 22.9 Brewing Range = 0-150 ppm. Sodium can occur in very high levels, particularly if you use a salt-based (i.e. ion exchange) water softener at home. In general, you should never use softened water for mashing. You probably needed the calcium it replaced and you definitely don’t need the high sodium levels. At levels of 70-150 ppm it rounds out the beer flavors, accentuating the sweetness of the malt. But above 200 ppm the beer will start to taste salty. The combination of sodium with a high concentration of sulfate ions will generate a very harsh bitterness. Therefore keep at least one or the other as low as possible, preferably the sodium. Chloride (Cl-1) Atomic Weight = 35.4 Equivalent Weight = 35.4 Brewing Range = 0-250 ppm. The chloride ion also accentuates the flavor and fullness of beer. Chloride does not have the same effect as Chlorine. However, concentrations above 300 ppm (from heavily chlorinated water or residual bleach sanitizer) can lead to mediciney flavors due to chlorophenol compounds. See Chapter 4 for information on reducing chlorine and chloramine from your brewing water.
Bicarbonate (HCO3-1) Molecular Weight = 61.0 Equivalent Weight = 61.0 Brewing Range = 0-50 ppm for pale, base-malt only beers. 50-150 ppm for amber colored, toasted malt beers. 150-250 ppm for dark, roasted malt beers. The carbonate family of ions is the big player in determining brewing water chemistry. Carbonate (CO3-2), is an alkaline ion, raising the pH, and neutralizing dark malt acidity. Its cousin, bicarbonate (HCO3-1), has half the buffering capability but actually dominates the chemistry of most brewing water supplies because it is the principal form for carbonates in water with a pH less than 8.4. Carbonate itself typically exists as less than 1% of the total carbonate/bicarbonate/carbonic acid species until the pH exceeds 8.4. There are two methods the homebrewer can use to bring the bicarbonate level down to the nominal 50-150 ppm range for most pale ales, or even lower for light lagers such as Pilsener. These methods are dilution and acidification. Carbonate can be precipitated (ppt) out as Calcium Carbonate (CaCO3) by aeration and boiling, as described in Chapter 4, according to the following reaction: 2HCO3-1 + Ca+2 ‹ CaCO3 (ppt) + H2O + CO2 gas where oxygen from aeration can act as a catalyst and the heat of boiling prevents the carbon dioxide from dissolving back into the water to create carbonic acid. The limitation of this method is that only the temporary hardness will be removed, and not even all of that. About one milliequivalent (50 ppm) of dissolved calcium carbonate will remain in solution, due to its solubility constant. Temporary hardness is the lesser of either the Total Alkalinity as CaCO3 or the Total Hardness as CaCO3, because the “temporary” aspect is actually the neutralization and precipitation of the calcium and bicarbonate. If the total hardness exceeds the total alkalinity, then nearly all of the alkalinity can be removed, down to the 50 ppm limit. If the total alkalinity as CaCO3 exceeds the total hardness (as it often does), then only part of the alkalinity, and nearly all of the calcium will be precipitated, which is not a good situation. You will probably want to add more calcium to the water to equalize the alkalinity. However, dark beer styles depend on having more alkaline water to achieve the right mash pH. This will be discussed in the sections to follow. Dilution is the easiest method of producing low carbonate water. Use distilled water from the grocery store (often referred to as Purified Water for use in steam irons) in a 1:1 ratio, and you will effectively cut your bicarbonate levels in half, although there will be a minor difference due to buffering reactions. Bottom Line—if you want to make soft water from hard water (e.g. to brew a Pilsener), dilution with distilled water is the easiest route. Acidifying the water to neutralize the bicarbonate and turn it into dissolved carbon dioxide is easy to do. There are several brewing software programs available, such as BeerSmith and Bru ‘N Water, that can calculate how many milliliters to add to your water volume to do the job. Sulfate (SO4-2) Molecular Weight = 96.0 Equivalent Weight = 48.0 Brewing Range = 50-150 ppm for normally bitter beers. 150-350 ppm for very bitter beers The sulfate ion also combines with Ca and Mg to contribute to permanent hardness. It accentuates hop bitterness, making the bitterness seem drier and more crisp. At concentrations over 400 ppm however, the resulting bitterness can become astringent and unpleasant, and at concentrations over 750 ppm, it can cause diarrhea. Sulfate is only weakly alkaline and does not contribute to the overall alkalinity of water. Sodium (Na+1) Atomic Weight = 22.9 Equivalent Weight = 22.9 Brewing Range = 0-150 ppm. Sodium can occur in very high levels, particularly if you use a salt-based (i.e. ion exchange) water softener at home. In general, you should never use softened water for mashing. You probably needed the calcium it replaced and you definitely don’t need the high sodium levels. At levels of 70-150 ppm it rounds out the beer flavors, accentuating the sweetness of the malt. But above 200 ppm the beer will start to taste salty. The combination of sodium with a high concentration of sulfate ions will generate a very harsh bitterness. Therefore keep at least one or the other as low as possible, preferably the sodium. Chloride (Cl-1) Atomic Weight = 35.4 Equivalent Weight = 35.4 Brewing Range = 0-250 ppm. The chloride ion also accentuates the flavor and fullness of beer. Chloride does not have the same effect as Chlorine. However, concentrations above 300 ppm (from heavily chlorinated water or residual bleach sanitizer) can lead to mediciney flavors due to chlorophenol compounds. See Chapter 4 for information on reducing chlorine and chloramine from your brewing water.
Water Hardness, Alkalinity, and Milliequivalents
Hardness and Alkalinity of water are often expressed “as CaCO3”. Hardness-as referring to the cation concentration, and alkalinity-as referring to the anions i.e. bicarbonate. If your local water analysis does not list the bicarbonate ion concentration (ppm), nor “Alkalinity as CaCO3”, to give the water’s buffering power to the mash pH, then you will need to call the water department and ask to speak to one of the engineers. They will have that information.
Calcium, and to a lesser extent magnesium, combine with bicarbonate to form chalk which is only slightly soluble in neutral pH (7.0) water. The total concentration of these two ions in water is termed “hardness” and is most noticeable as carbonate scale on plumbing. Water Hardness is often listed on municipal water data sheets as “Hardness as CaCO3” and is equal to the sum of the Ca and Mg concentrations in milliequivalents per liter (mEq/l) multiplied by 50 (the “equivalent weight” of CaCO3). An “equivalent” is a mole of an ion with a charge, + or –, of 1. The equivalent weight of Ca+2 is half of its atomic weight of 40, i.e. 20. Therefore, if you divide the concentration in ppm or mg/l of Ca+2 by 20, you have the number of milliequivalents per liter of Ca+2. Adding the number of milliequivalents of calcium and magnesium together and multiplying by 50 gives the hardness as milliequivalents per liter of CaCO3.
(Ca (ppm)/20 + Mg (ppm)/12.1) x 50 = Total Hardness as CaCO3
These operations are summarized in Table 20.
Water pH
You would think that the pH of the water is important but actually it is not. It is the pH of the mash that is important, and that number is dependent on all of the ions we have been discussing. In fact, the ion concentrations are not relevant by themselves and it is not until the water is combined with a specific grain bill that the mash pH is determined, and it is that pH which affects the activity of the mash enzymes and the propensity for the extraction of astringent tannins from the grain husks.
Many brewers have made the mistake of trying to change the pH of their water with salts or acids to bring it to the mash pH range before adding the malts. You can do it that way if you have enough experience with a particular recipe to know what the mash pH will turn out to be; but it is like putting the cart before the horse. It is better to start the mash, measure the pH with a pH meter and then make any additions you feel are necessary to bring the pH to the proper range. Most of the time adjustment won’t be needed due to the natural acidity of the malts.
However, most people don’t like to trust to luck or go through the trial and error of testing the mash pH and adding salts to get the right pH. There is a way to estimate your mash pH before you start and this method is discussed in a section to follow, but first, let’s look at how the grain bill affects the mash pH.
Balancing the Malts and Minerals
Let me state the goal right up front: for best results, the mash pH should be 5.2–5.6 when measured at room temperature on a cooled sample. (At mash temperature the pH will measure about 0.3 lower due to greater dissociation of the hydrogen ions, so ~4.9-5.3.) When you mash 100% base malt grist with distilled water, you will usually get a mash pH between 5.7–5.8 (measured at room temperature). The natural acidity of roasted specialty malt additions (e.g. caramel, chocolate, black) to the mash can have a large effect on the pH. Using a dark crystal or roasted malt as 20% of the grainbill will often bring the pH down by half a unit (.5 pH). In distilled water, 100% caramel malt would typically yield a mash pH of 4.5–4.8, chocolate malt 4.3–4.5, and black malt 4.0–4.2. The chemistry of the water determines how much of an effect each malt addition has.
The best way to explain this is to describe two of the world’s most famous beers and their brewing waters. See Table 21. The Pilsen region of the Czech Republic was the birthplace of the Pilsener style of beer. A Pils is a soft, golden clear lager with a very clean hoppy taste. The water of Pilsen is very soft, free of most minerals and very low in bicarbonates. The Pilsen brewers actually used calcium salt additions with this water to bring the pH down to the target mash range of 5.1-5.5 using only the pale lager malts. Adding calcium salts is often referred to as “Burtonization” and was considered high technology at the time when the pilsener style was developed.
The other beer to consider is Guinness, the famous stout from Ireland. The water of Ireland is high in bicarbonates (HCO3-1), and has a fair amount of calcium but not enough to balance the bicarbonate. This results in hard, alkaline water with a lot of buffering power. The high alkalinity of the water makes it difficult to produce light pale beers that are not harsh tasting. The water does not allow the pH of a 100% base malt mash to hit the target range, it remains higher (>pH 6) and this extracts phenolic and tannin compounds from the grain husks. The lower pH of an optimum mash (5.1-5.5) normally prevents these compounds from appearing in the beer. But why is this region of the world renowned for producing outstanding dark beers? The reason is the dark malt itself. The highly roasted black malts used in making Guinness Stout add acidity to the mash. The natural acidity of these malts counteracts the alkalinity of the carbonates in the water, lowering the mash pH into the target range.
The fact of the matter is that dark beer cannot be brewed in Pilsen, and light lagers can’t be brewed in Dublin without adding or removing the proper type and amount of buffering salts. Before you brew your first all-grain beer, you should get a water analysis from your local water utility and look at the mineral profile to establish which styles of beer you can best produce. The use of roasted malts such as Caramel, Chocolate, Black Patent, and the toasted malts such as Munich and Vienna, can be used successfully in areas where the water is alkaline (i.e., a pH greater than 7.5 and a carbonate level of more than 200 parts per million) to produce good mash conditions. If you live in an area where the water is very soft (like Pilsen), then you can add brewing salts to the mash and sparge water to help achieve the target pH. The next two sections of this chapter, Residual Alkalinity and Mash pH, and Using Salts for Brewing Water Adjustment, discuss how to do this.
Table 21 lists examples of classic beer styles and the mineral profile of the city that developed them. By looking at the city and its resulting style of beer, you will gain an appreciation for how malt chemistry and water chemistry interrelate. Descriptions of the region’s beer styles follow.
Pilsen
The very low hardness and alkalinity allow the proper mash pH to be reached with only base malts, achieving the soft rich flavor of fresh bread. The lack of sulfate provides for a mellow hop bitterness that does not overpower the soft maltiness; noble hop aroma is emphasized.
Dublin
Famous for its stout, Dublin has the highest bicarbonate concentration of the cities of the British Isles, and Ireland embraces it with the darkest, maltiest beer in the world. The low levels of sodium, chloride and sulfate create an unobtrusive hop bitterness to properly balance all of the malt.
Dortmund
Another city famous for pale lagers, Dortmund Export has less hop character than a Pilsner, with a more assertive malt character due to the higher levels of all minerals. The balance of the minerals is very similar to Vienna, but the beer is bolder, drier, and lighter in color. The sodium and chloride bring out a rich roundness to the malt character.
Vienna
The water of this city is similar to Dortmund, but lacks the level of calcium to balance the carbonates, and lacks as well the sodium and chloride for flavor. Attempts to imitate Dortmund Export failed miserably until a percentage of toasted malt was added to balance the mash, and Vienna’s famous red-amber lagers were born.
Munich
Although moderate in most minerals, alkalinity from carbonates is high. The smooth flavors of the dunkels, bocks and oktoberfests of the region show the success of using dark malts to balance the carbonates and acidify the mash. The relatively low sulfate content provides for a mellow hop bitterness that lets the malt flavor dominate.
London
The higher carbonate level dictated the use of toasted and dark malts to balance the mash, but the chloride and high sodium content also smoothed the flavors out, resulting in the well known ruby-dark porters and copper-colored pale ales.
Edinburgh
Think of misty Scottish evenings and you think of Strong Scotch ale—dark ruby highlights, a sweet malty beer with a mellow hop finish. The water is similar to London’s but with a bit more bicarbonate and sulfate, making a beer that can embrace a heavier malt body while using less hops to achieve balance.
Burton-on-Trent
Compared to London, the calcium and sulfate are remarkably high, but the hardness and alkalinity are balanced to nearly the degree of Pilsen. The high level of sulfate and low level of sodium produce an assertive, clean hop bitterness. Compared to the ales of London, Burton ales are paler, but much more bitter, although the bitterness is balanced by the higher alcohol and body of these ales.
Residual Alkalinity and Mash pH
Before you conduct your first mash, you probably want to be assured that it will probably work. Many people want to brew a dark stout or a light pilsener for their first all-grain beer, but these very dark and very light styles need the proper brewing water to achieve the desired mash pH. While there is not any surefire way to predict the exact pH, there are empirical methods and calculations that can put you in the ballpark, just like for hop IBU calculations. To estimate your probable mash pH, you will need the calcium, magnesium and alkalinity ion concentrations from your local water utility report.
Background:In 1953, German brewing scientist Paulas Kohlbach determined that 3.5 equivalents (Eq) of calcium reacts with malt phytin to release 1 equivalent of hydrogen ions which can “neutralize” 1 equivalent of water alkalinity. Magnesium, the other water hardness ion, also works but to a lesser extent, needing 7 equivalents to neutralize 1 equivalent of alkalinity. This chemical reaction does not require enzyme activity or an acid rest. Alkalinity that is not neutralized is termed “residual alkalinity” (abbreviated RA).
On a per volume basis, this can be expressed as: mEq/L RA = mEq/L Alkalinity - [(mEq/L Ca)/3.5 + (mEq/L Mg)/7] where mEq/L is defined as milliequivalents per liter.
This residual alkalinity will cause an all-base-malt mash to have a higher pH than is desirable, resulting in tannin extraction, etc. To counteract the RA, brewers in alkaline water areas like Dublin added dark roasted malts that have a natural acidity that brings the mash pH back into the right range. To help you determine what your RA is, and what your mash pH will probably be for a 100% base malt mash, I have put together a nomograph (Figure 98, on the inside back cover) that allows you to read the pH after marking-off your water’s calcium, magnesium and alkalinity levels. To use the chart, you mark off the calcium and magnesium levels to determine an “effective” hardness (EH), then draw a line from that value through your alkalinity value to point to the RA and the approximate pH.
After determining your probable pH, the chart offers you two options:a) You can plan to brew a style of beer that approximately matches the color guide above the pH scaleb) You can estimate an amount of calcium, magnesium, or bicarbonate to add to the brewing water to hit a targeted pH.I will show you how this works in the following examples. [figure 94 – nomograph for Los Angeles]
Determining the Styles that Best Suit your Water
1. A water report for Los Angeles, CA, states that the three ion concentrations are:Ca (ppm) = 70Mg (ppm) = 30Alkalinity = 120 ppm as CaCO3
2. Mark these values on the appropriate scales. (Indicated by circles and triangle on Figure 94.)
3. Draw a line between the Ca and Mg values to determine the Effective Hardness (middle circle).
4. From the value for EH, draw a line through the Alkalinity value to intersect the RA/pH scale.
This is your Residual Alkalinity (50), which indicates that the mash pH will be approximately 0.1 unit higher than the nominal.
5. Looking directly above the pH scale, the color guide shows a medium-light shade which corresponds to most amber, red and brown ales and lagers. Most Pale Ale, Brown Ale and Porter recipes can be brewed with confidence.
[figure 95 – nomograph for calcium addition]
2. Mark these values on the appropriate scales. (Indicated by circles and triangle on Figure 94.)
3. Draw a line between the Ca and Mg values to determine the Effective Hardness (middle circle).
4. From the value for EH, draw a line through the Alkalinity value to intersect the RA/pH scale.
This is your Residual Alkalinity (50), which indicates that the mash pH will be approximately 0.1 unit higher than the nominal.
5. Looking directly above the pH scale, the color guide shows a medium-light shade which corresponds to most amber, red and brown ales and lagers. Most Pale Ale, Brown Ale and Porter recipes can be brewed with confidence.
[figure 95 – nomograph for calcium addition]
Table 19 - Los Angeles Metro Water District Quality Report (1996 data)
Table 20 - Ion Concentration Conversion Factors
Table 21 – Water Profiles from Notable Brewing Cities
Values are in parts per million.
Sources:
Burton—”Malting and Brewing Science Vol. 1”Dortmund—Noonen, G., “New Brewing Lager Beer”Dublin— “The Practical Brewer”, Edinburgh—Noonen, G., “New Brewing Lager Beer”London—Westermann and Huige, “Fermentation Technology”, Munich—”Malting and Brewing Science Vol. 1”Pilsen—Wahl-Henius,“American Handy Book”Vienna—Noonen, G., “New Brewing Lager Beer”
Author's Note 2025: Several of these profiles don't add up to a realistic composition, but they are what was published. Take them with a grain of salt.
Figure94 - Residual Alkalinity for Los Angeles.
Figure 95—Using nomograph to determine calcium addition.
Figure 96—Using nomograph to determine bicarbonate addition.
Table 22 – Brewing Salts for Water Adjustment
Table 23 - Acids for Mash pH Adjustment
Figure 97—Using nomograph to determine milliequivalents of acid to lower RA.
Determining Calcium Additions to Lower the
Mash pH
But what if you want to brew a much paler beer, like a Pilsener or a Helles? Then you will need to add more calcium to balance the alkalinity that your malt selection cannot.1. Go back to the nomograph and pick a point on the RA scale that is within the desired color range. In this example, I picked an RA value of -75.2. Draw a line from this RA value back through your Alkalinity value (120 from the water report), and determine your new EH value (~190).3. From the original Mg value (30) from the report, draw a line through the new EH value and determine the new Ca value needed to produce this effective hardness.
(Author’s note 2025: The new calcium value is about 250 ppm, which is much higher than the recommended maximum calcium concentration of 150 ppm. Therefore, some acidification to decrease the alkalinity to 60 ppm (for example) would be a better approach to brewing a pale beer with this water.)4. Subtract the original Ca value from the new Ca value to determine how much calcium (per unit volume) needs to be added. In this example, 180 ppm of additional calcium is needed.Author’s note 2025: Decreasing the total alkalinity of the water to 60 ppm as CaCO3 by acidification would change the necessary EH to about 125, and the total calcium to about 150 ppm as CaCO3.5. The source for the calcium can be either calcium chloride or calcium sulfate (gypsum). (Calcium chloride is more appropriate than gypsum for lagers.) See the following section for guidelines on just how much of these salts to add.
Determining Bicarbonate Additions to Raise the Mash pH
[See figure 96 – bicarbonate nomograph]
Likewise, you can determine how much additional alkalinity (HCO3) is needed to brew a dark stout if you have water with low alkalinity.
1. You determine your residual alkalinity from your water report (e.g., ~50), and then determine your desired RA based on the color of the style you want to brew. In this example, I have selected an RA of 100, which corresponds to a dark beer on the color guideline.
2. The difference is that this time you draw a line from the desired RA to the original EH, passing through a new Alkalinity (~170 ppm as CaCO3 or ~205 ppm HCO3).
3. Subtract the original alkalinity from the new alkalinity to determine the additional bicarbonate needed. (60 ppm HCO3 or 50 ppm Alkalinity as CaCO3) The additional bicarbonate can best be added by using sodium bicarbonate (baking soda).
Determining Bicarbonate Additions to Raise the Mash pH
[See figure 96 – bicarbonate nomograph]Likewise, you can determine how much additional alkalinity (HCO3) is needed to brew a dark stout if you have water with low alkalinity.1. You determine your residual alkalinity from your water report (e.g., ~50), and then determine your desired RA based on the color of the style you want to brew. In this example, I have selected an RA of 100, which corresponds to a dark beer on the color guideline.2. The difference is that this time you draw a line from the desired RA to the original EH, passing through a new Alkalinity (~170 ppm as CaCO3 or ~205 ppm HCO3).3. Subtract the original alkalinity from the new alkalinity to determine the additional bicarbonate needed. (60 ppm HCO3 or 50 ppm Alkalinity as CaCO3) The additional bicarbonate can best be added by using sodium bicarbonate (baking soda).
Using Salts for Brewing Water Adjustment
Brewing water can be adjusted by the addition of brewing salts. To calculate how much to add, use the nomograph or brewing software to figure out what concentration is desired and then subtract your water’s ion concentration to determine the difference. Next, consult Table 22—Brewing Salts to see how much of an ion a particular salt can be expected to add. Don’t forget to multiply the difference in concentration by the total volume of water you are working with.Let’s look back at the nomograph example where we determined that we needed 180 ppm of additional calcium ion. Let’s say that 4 gallons of water are used in the mash.
Author’s note 2025: Yes, 180 ppm of additional calcium is unreasonable, the beer would taste minerally, but for the sake of example...)
1. Choose a salt to use to add the needed calcium. Let’s use gypsum.2. From Table 23, gypsum adds 61.5 ppm of Ca per gram of gypsum added to 1 gallon of water.3. Divide the 180 ppm by 61.5 to determine the number of grams of gypsum needed per gallon to make the desired concentration. 145/61.5 = 2.4 grams4. Next, multiply the number of grams per gallon by the number of gallons in the mash (4). 2.4 x 4 = 9.6 grams, which can be rounded to 10 grams.5. Unless you have a gram scale handy, you will want to convert that to teaspoons which is more convenient. There are about 4 grams of gypsum per teaspoon, which gives us 10/4 = 2.5 teaspoons of gypsum to be added to the mash.6. Lastly, you need to realize how much sulfate this addition has made. 2.5 grams per gallon equals 368 ppm of sulfate added to the mash, which is a lot. In this case, it would probably be a good idea to use calcium chloride for half of the addition.
Table 23 provides information on the use and results of each salt’s addition. Brewing salts should be used sparingly to make up for gross deficiencies or overabundance of ions. The concentrations given are for 1 gram dissolved in 1 gallon of distilled water. Dissolution of 1 gram of a salt in your water will probably result in a slightly different value due to your water’s specific mineral content and pH. However, the results should be reasonably close.
There are several brewing software programs that are very handy for these types of water calculations as well as all types of mashing and recipe calculations. Two examples are Beersmith at www.beersmith.com, and Palmers Brewing Water Adjustment worksheet at www.howtobrew.com. The functionality of these brewing applications has been thoroughly reviewed, and I can assure you that they are comprehensive and easy to use.
Using Acids for Brewing Water Adjustment
Acid additions are another way to lower mash pH to brew pale beers in high alkalinity areas. Note: Always wear appropriate safety equipment when working with strong acids. At a minimum you should wear rubber gloves and eye protection. Lactic acid is not very dangerous but will cause skin irritation. Hydrochloric acid will cause severe skin burns however, so more care needs to be taken with its use. The vapors are corrosive and very irritating if inhaled. Read the warnings on the containers and take appropriate precautions.
Determining Acid Additions to Lower the Mash pH1. In this example, a local water report (Ca = 70, Mg = 30, Alk. = 180) indicates a residual alkalinity of 110, and an increase of about 0.15 to mash pH, which means that the water is best suited for brewing darker beers (if untreated). See Figure 97.2. Pick a point on the RA scale that is within the desired beer color range for a pale beer. For this example, I picked an RA value of -50.3. Draw a line from this RA value back thru the Alkalinity as CaCO3 scale to the Effective Hardness value as shown. This line intersects the Total Alkalinity scale at about 20 ppm as CaCO3. The difference in the total alkalinity is 160 ppm as CaCO3.4. The difference in alkalinity is the amount of acid you need to add per liter of the mash. Divide the Alkalinity as CaCO3 difference by 50 to get mEq/mL of Alkalinity.160 mg/L ÷ 50 = 3.2 mEq/mL of Alkalinity as CaCO35. To neutralize 3.2 mEq/mL of alkalinity, we will need 3.2 mEq/mL of acid.6. There are several acids you can choose from to affect your mash pH. (See Table 23) The most readily available are lactic acid and hydrochloric (muriatic) acid. Phosphoric acid is not recommended because it reacts chemically with calcium in the mash and changes the whole playing field, rather than simply adjusting the pH. If the mash water volume is 15 liters (4 gal.), then 3.2 x 15 L = 48 mEq of acid are needed to neutralize the alkalinity and bring the RA to -50.Using hydrochloric acid: 48 ÷ 12 mEq/mL = 4 milliliters Using lactic acid: 48 ÷ 11.8 mEq/mL = ~ 4.1 millilitersIf you are using common muriatic acid (e.g. used for swimming pool pH correction), the concentration may be different. If so, then you simply need to ratio the concentrations to arrive at the final volume. If the muriatic acid is a 32% solution rather than the laboratory standard 37%, the volume required is 37/32 x 3.2 ml = 3.7 milliliters.A dosing syringe like those used for measuring medicine for babies works well here.
Determining Acid Additions to Lower the Mash pH1. In this example, a local water report (Ca = 70, Mg = 30, Alk. = 180) indicates a residual alkalinity of 110, and an increase of about 0.15 to mash pH, which means that the water is best suited for brewing darker beers (if untreated). See Figure 97.2. Pick a point on the RA scale that is within the desired beer color range for a pale beer. For this example, I picked an RA value of -50.3. Draw a line from this RA value back thru the Alkalinity as CaCO3 scale to the Effective Hardness value as shown. This line intersects the Total Alkalinity scale at about 20 ppm as CaCO3. The difference in the total alkalinity is 160 ppm as CaCO3.4. The difference in alkalinity is the amount of acid you need to add per liter of the mash. Divide the Alkalinity as CaCO3 difference by 50 to get mEq/mL of Alkalinity.160 mg/L ÷ 50 = 3.2 mEq/mL of Alkalinity as CaCO35. To neutralize 3.2 mEq/mL of alkalinity, we will need 3.2 mEq/mL of acid.6. There are several acids you can choose from to affect your mash pH. (See Table 23) The most readily available are lactic acid and hydrochloric (muriatic) acid. Phosphoric acid is not recommended because it reacts chemically with calcium in the mash and changes the whole playing field, rather than simply adjusting the pH. If the mash water volume is 15 liters (4 gal.), then 3.2 x 15 L = 48 mEq of acid are needed to neutralize the alkalinity and bring the RA to -50.Using hydrochloric acid: 48 ÷ 12 mEq/mL = 4 milliliters Using lactic acid: 48 ÷ 11.8 mEq/mL = ~ 4.1 millilitersIf you are using common muriatic acid (e.g. used for swimming pool pH correction), the concentration may be different. If so, then you simply need to ratio the concentrations to arrive at the final volume. If the muriatic acid is a 32% solution rather than the laboratory standard 37%, the volume required is 37/32 x 3.2 ml = 3.7 milliliters.A dosing syringe like those used for measuring medicine for babies works well here.
Adjusting Sparge Water
Lowering the pH of your sparge water is usually unnecessary. The malts in the mash have a lot of buffering power that will last until the gravity falls below 1.012. Batch sparge and no-sparge techniques typically have second runnings that are 1.016 or greater, so tannin and silicate extraction are inhibited. If you live in an area of high alkalinity and know from experience that you need to lower the pH of your sparge water, then add the same concentration that you used for the mash. This will maintain the pH equilibrium in your mash as you sparge.
Likewise, brewing salt additions of calcium can be added to the sparge water to help maintain pH during the sparge. The salts used must be readily soluble, like calcium chloride or calcium sulfate. My final advice on water treatment is that if you want to brew a pale beer and have water that is very high in carbonates and low in calcium, then your best bet is to use bottled water* from the store or to dilute your water with distilled water and add gypsum or calcium chloride to make up the calcium deficit. Watch your sulfate and chloride counts though.Good Luck!* You should be able to get an analysis of the bottled water by calling the manufacturer. I have done this with a couple of different brands.
Likewise, brewing salt additions of calcium can be added to the sparge water to help maintain pH during the sparge. The salts used must be readily soluble, like calcium chloride or calcium sulfate. My final advice on water treatment is that if you want to brew a pale beer and have water that is very high in carbonates and low in calcium, then your best bet is to use bottled water* from the store or to dilute your water with distilled water and add gypsum or calcium chloride to make up the calcium deficit. Watch your sulfate and chloride counts though.Good Luck!* You should be able to get an analysis of the bottled water by calling the manufacturer. I have done this with a couple of different brands.