Beer Basics Water Treatment in Brewing April 21, 2007

Today’s Topics Introduction Ions in Brewing – Important Cations – Important Anions Water Analysis – pH – Alkalinity – Water Hardness Temporary Hardness Permanent Hardness – Local Water Profile Brewing Water Treatment – Carbon Filtration – Reverse Osmosis and Distillation – Boiling – Mineral Salts Brewing Water Additions – Acidification Examples Famous Brewing Waters

Introduction Water constitutes around 90% of the volume of beer, so we cannot ignore the impact of water on our brews Many brewers treat their brewing water to improve the quality of their beers Some famous brewing regions developed certain beer styles as a result of the local brewing water

Ions in Brewing Ions are electrically charged groups of atoms. Positively charged ions are called cations, and negatively charged ions are called anions.

Ions in Brewing Important Cations Calcium (Ca +2 ) – Contributes to permanent water hardness – Interacts with malt phosphates which lowers pH during mashing and boiling – Helps yeast flocculation and beer clarification – Also aids protein coagulation during hot and cold breaks – According to Dave Miller the optimum is mg/l.

Ions in Brewing Important Cations Magnesium (Mg +2 ) – Contributes to permanent water hardness – Lowers mash pH similar to Calcium, but not as effective – Usually sufficient amount present in malt, so seldom have to add to brewing water. – Good yeast nutrient at mg/l. However, at 30+ mg/l it can impart a sharp sour/bitter flavor

Ions in Brewing Important Cations Sodium (Na + ) – Poisonous to yeast and harsh tasting when levels are too high. – Unpleasant harshness when combined with Sulfate – Contributes sour salty taste at reasonable levels. For brewing, should be below 50 mg/l

Ions in Brewing Important Anions Bicarbonate (HCO 3 ) - – Neutralizes acids in dark malts – Acts as a pH buffer – Under 50 mg/l unless it is balanced by Calcium or dark malts.

Ions in Brewing Important Anions Sulfate (SO 4 ) -2 – Accentuates hop bitterness and dryness at high concentrations. It is strongly bitter above 500 mg/l – For non highly hopped beers, levels should be below 150 mg/l – Creates an unpleasant harshness if combined with Sodium

Ions in Brewing Important Anions Chloride (Cl) - – Enhances sweetness at low concentrations, but at high levels it impairs yeast flocculation. – Increases beer stability and improves clarity – For light beers mg/l is common; however, it can be as high as 350 mg/l for beers with gravity larger than 1.050

Water Analysis - pH pH, or potential hydrogen, is important in brewing – Enzymes that break down starches work best over a pH range of 5.2 – 5.5 – If pH of sparging water is greater than 6.0, then tannins can leak into wort causing harsh flavors. – Rapid drop in pH during fermentation is common, which inhibits bacterial activity

Water Analysis - pH Pure water contains mostly H 2 O molecules and some disassociated hydrogen H + ions and hydroxide (OH - ) ions. pH is a measure of the relative concentrations of the two ions. It is a logarithmic scale from 1 to 14. pH = -log[H + ] where [H + ]=moles per liter of H +

Water Analysis - pH For pure water, the ions have equal concentrations and the pH is 7.0 or neutral. Solutions with a higher concentration of H +, have a pH below 7 and are acidic. Solutions with a higher concentration of OH -, have a pH above 7 and are basic.

Water Analysis - Alkalinity Alkalinity is the amount of alkaline ions present and is usually expressed as an equivalent amount of CaCO 3 For water pH between 7 and 9, alkalinity is basically the bicarbonate ion, expressed as an equivalent amount of CaCO 3 Alkalinity, as equivalent CaCO 3, should be less than 50 mg/l for brewing pale beers

Water Analysis - Hardness Informally, water hardness was determined by the amount of suds produced in soap, the harder the water, the fewer the suds. Water hardness is measured as the amount of Calcium (Ca +2 ) and Magnesium (Mg +2 ) dissolved in water and is usually expressed as an equivalent amount of CaCO 3 Hardness = (100/40)* (mg/l of Calcium) + (100/24)* (mg/l of Magnesium)

Water Analysis - Hardness Temporary Hardness Calcium reacts with bicarbonate (HCO 3 ) -, when heated, to precipitate Calcium carbonate (CaCO 3 ), which reduces the amount of Calcium. The Calcium that can be removed from the water through this boiling process is called temporary hardness

Water Analysis - Hardness Permanent Hardness Permanent hardness is the water hardness that remains after boiling When alkalinity exceeds hardness, then the water hardness is mostly temporary. Conversely, if the hardness exceeds the alkalinity, the difference indicates permanent sulfate hardness.

Water Analysis Local Water Profile Most municipal water supplies publish the profile of their water Many suburbs near Dallas receive their water from the North Texas Municipal Water District See their website for a monthly analysis of their water

Water Analysis Local Water Profile Total Hardness = 221, which is moderately hard water Total Alkalinity = 89, which is high if brewing pale beers Magnesium and Sodium are high for brewing water. Sulfates are high for brewing beers that are not highly hopped

Brewing Water Treatment Carbon Filtration Most municipal water supplies are treated with chlorine to inhibit bacterial growth. Chlorine can interact with wort to produce chlorophenols which can impart a plastic taste to beer Chlorine should be removed from brewing water. To remove chlorine you can use a carbon filter

Brewing Water Treatment Reverse Osmosis and Distillation RO removes about 94% of the ions from water. If you use RO, then may need to add mineral salts to increase the calcium level to an appropriate level. Distillation removes all ions from water. Complete distillation is not recommended because it removes all yeast nutrients, however, partial distillation may be appropriate

Brewing Water Treatment Boiling Recall that calcium reacts with bicarbonate (HCO 3 ) -, when heated to a boil, to precipitate calcium carbonate (CaCO 3 ), which reduces the amount of Calcium and the amount of bicarbonate. The reduction in bicarbonate will lower the pH of the water The process removes about 3 mg/l of calcium for every 5 mg/l of bicarbonate removed

Mineral Salts Mineral salts are adding to brewing water to: – Change the mash or sparge pH For pale malt mashes adding calcium sulfate will lower mash pH. For dark malt mashes adding calcium carbonate will increase mash pH – Replicate the water profile of a famous brewing region – To achieve specific flavors in beer

Mineral Salts Common mineral salts added to brewing water – Calcium Sulfate (Gypsum) CaSO 4 ∙2H 2 O Ca 23.28%, SO %, H 2 O 20.93% Increases water hardness and sulfate levels – Magnesium Sulfate (Epsom Salts) MgSO 4 ∙7H 2 O Mg 14%, SO 4 55%, H 2 O 31% Increases water hardness and sulfate levels – Calcium Carbonate (Chalk) CaCO 3 Ca 40.04%, CO % Increases Calcium and strongly buffers mash pH

Mineral Salts Common mineral salts added to brewing water – Calcium Chloride CaCl 2 ∙2H 2 O Ca 27.26%, Cl %, H 2 O 24.51% Adds Calcium and saltiness – Sodium Chloride (Table Salt) NaCl Na 39.34%, Cl 60.66% Enhances bitterness and fullness of beer

Mineral Salts Brewing Water Additions One gram of a mineral salt in one gallon of water at 68 o F will increase the total dissolved solids by mg/l. The is the conversion from grams per gallon to milligrams per liter.

Mineral Salts Brewing Water Additions For example, If you add 1.5 grams of gypsum to 10 gallons of your brewing water, how much of the Calcium ion have you added to the water? Answer: Mineral Salt ppm (1.5g/10gallon)*(1gallon/3.785liters)(1000mg/1g)=39.63mg/l Calcium ppm (39.63mg/l*.2328 )= 9.22 mg/l of Calcium

Acidification The pH of brewing water can be reduced by adding a small amount of food grade acid. Typically, lactic, phosphoric, or sulfuric acid are used. As a general guide, you can add small amounts of food grade acid until the brewing water pH is around 7. For modified pale malts that will not undergo acid or protein rests, then you should add food grade acid until the brewing water pH is 6.0

Acidification Acids can be used more precisely to lower alkalinity, which will lower mash pH The amount of acid in milligrams/milliliter for common acids used in brewing: Lactic acid 85-90% w/w: 1,020 mg/ml Phosphoric acid 85-88% w/w: 1,445 gm/ml Sulfuric acid 95-98% w/w: 1,766 mg/ml

Acidification To calculate the milliliters of acid required to lower alkalinity use the formula: (Alkalinity Reduction in CaCO 3 )*3.7854*gallons of water milligrams of acid per milliliters

Acidification Example If your brewing water has a pH of 7.9 and an alkalinity of 89, how many ml of 85% lactic acid should you add to 8 gallons of brewing water to reduce the alkalinity to 50 mg/l? Answer lactic acid ml = (89-50)*3.7854*8 = 1.2 ml 1,020 Note that a teaspoon is 5 ml

Famous Brewing Waters The water at Burton upon Trent is very hard and the sulfate levels are extremely high. The high sulfate levels accentuate the bitterness in English Bitters and Pale ales The water in London, Dublin and Munich is high in bicarbonate which balances the dark malts used to brew porters, stouts, and bocks, in the respective regions

Famous Brewing Waters Plzen water is very soft with low concentrations of dissolved ions. Decoction mashing is common in Plzen, in part due to soft water. The decoction process allows enzymes to work even though the calcium levels are very low.

Famous Brewing Waters* MineralCalciumMagnesiumSodiumSulfateBicarbonateChloride Plzen Dortmund Munich Vienna Burton Dublin Edinburgh London Plano *Data from Greg Noonan's water workshop at the 1991 AHA Conference and are in ppm (mg/l)