Water Chemistry / Brewing Water Calculatorv1.0.0

Adjusting brewing water starts with a known source profile and a target profile for the beer style, then adds salts and acids to close the gap. Enter your source water values, set a target based on your beer style, specify the batch size, and add each salt or acid adjustment to see how it changes the final mineral concentrations in ppm. The calculator also reports residual alkalinity, total hardness, total alkalinity, and the chloride to sulfate ratio to help you dial in mash chemistry.

• Select a Water Profile Preset from the dropdown (such as Distilled/RO, Burton on Trent, Dublin, Pilsen, or Vienna) to auto-populate the source water fields, or choose Custom and enter your own water report values for Calcium, Magnesium, Sodium, Chloride, Sulfate, and Bicarbonate in parts per million (ppm).
• Select a Target Profile Preset for your beer style (Pale Ale, IPA, Pilsner, Stout, or Porter) to auto-fill the target ion concentrations, or choose Custom and enter your own target values.
• Enter your Batch Size in gallons or liters. This value scales the ion contributions from each salt or acid addition.
• Click Add Addition to create a new row. Select the type of addition (Gypsum, Calcium Chloride, Epsom Salt, Table Salt, Baking Soda, Chalk, Pickling Lime, Lactic Acid 88 percent, or Phosphoric Acid 10 percent), enter the amount in grams or teaspoons, and select the unit. Each row shows the ion contributions for that specific addition.
• Click Calculate to compute the adjusted water profile. The results display the final concentrations for each ion in ppm, as well as derived properties including total hardness, total alkalinity, residual alkalinity, and the chloride to sulfate ratio.
• Review the Cl:SO₄ Ratio output to evaluate the balance. A ratio below 0.5 favors hop bitterness, 0.5 to 0.8 is balanced bitter, 0.8 to 1.5 is balanced, 1.5 to 2.0 is balanced malty, and above 2.0 is very malty and sweet.
• Open the Settings panel to adjust the decimal precision for all outputs or to enable formula display, which shows the step by step calculations for each derived property.
• Click Reset to clear all inputs and additions and restore the tool to its default state.

The tool uses standard brewing water chemistry formulas. Ion contributions per gram of each salt in one gallon: Gypsum (CaSO₄·2H₂O) contributes 61.5 ppm Ca and 147.4 ppm SO₄; Calcium Chloride (CaCl₂) contributes 72 ppm Ca and 127 ppm Cl; Epsom Salt (MgSO₄·7H₂O) contributes 26 ppm Mg and 103 ppm SO₄; Table Salt (NaCl) contributes 104 ppm Na and 160 ppm Cl; Baking Soda (NaHCO₃) contributes 75 ppm Na and 191 ppm HCO₃; Chalk (CaCO₃) contributes 106 ppm Ca and 162 ppm HCO₃; Pickling Lime (Ca(OH)₂) contributes 143 ppm Ca and 122 ppm alkalinity; Lactic Acid (88 percent) reduces HCO₃ by 60 ppm per gram; Phosphoric Acid (10 percent) reduces HCO₃ by 70 ppm per ml. Total Hardness = 2.5 × Ca + 4.1 × Mg. Total Alkalinity = HCO₃ × 50 / 61. Residual Alkalinity = HCO₃ − (Ca / 3.5 + Mg / 7). All values are in ppm as CaCO₃ equivalents where applicable. Adjustments scale linearly with batch size.

Water chemistry shapes hop expression, malt balance, and mash pH, so matching a water profile to a beer style is a routine step in serious recipe formulation. Small mineral adjustments change the chloride to sulfate balance that tilts a beer toward crisp bitterness or round maltiness.

• Pale Ale Brewing: A homebrewer starts with soft tap water (Ca 20, Mg 5, Cl 15, SO₄ 10) and wants a balanced pale ale profile. They select the Pale Ale target preset and add Gypsum and Calcium Chloride to reach Ca 100, Cl 75, SO₄ 150, achieving a Cl:SO₄ ratio of 0.5 for a crisp, balanced bitterness.
• IPA Water Adjustment: A brewer using RO water (all ions zero) selects the IPA target profile and adds Gypsum (4 grams) and Calcium Chloride (2 grams) to a 5 gallon batch. The tool calculates final concentrations of Ca 120, Cl 50, SO₄ 250, with a Cl:SO₄ ratio of 0.2, emphasizing hop bitterness and dryness.
• Pilsner Soft Water: To replicate Pilsen water for a Czech Pilsner, a brewer starts with distilled water and avoids mineral additions, keeping all ions under 10 ppm. The tool confirms the low residual alkalinity (near zero) and minimal hardness, ideal for delicate malt expression.
• Stout and Porter: Brewing a dark beer requires higher chloride and moderate bicarbonate. A brewer selects the Stout target, adds Calcium Chloride (3 grams) and Baking Soda (1 gram) to 5.5 gallons, and verifies the Cl:SO₄ ratio exceeds 2.0 for a smooth, malty character.
• Mash pH Control: A brewer with high bicarbonate tap water (HCO₃ 250) adds Lactic Acid (2 grams) to cut alkalinity. The tool shows the lowered HCO₃ and residual alkalinity, which track the direction mash pH will move, helping the brewer avoid the high mash pH that extracts tannins from the grain.
• Recipe Development: During recipe formulation, a brewer experiments with different salt additions in the calculator, comparing profiles for Burton on Trent (high sulfate) versus Dublin (high bicarbonate) to see how each affects the final water chemistry and Cl:SO₄ balance.