tags: [] - coffee/brewing - coffee/brewing/water aliases: - CaCl2 coffee water - Calcium chloride water recipe - Calcium chloride mineral

Calcium Chloride¶

Tags: #coffee/brewing #coffee/brewing/water Aliases: CaCl2 coffee water, Calcium chloride water recipe, Calcium chloride mineral Related: Water in Coffee MOC | Calcium in Coffee Water | DIY Water Recipes | Chloride in Coffee Water | Magnesium vs. Calcium Status: ✅ Complete

Overview¶

Calcium chloride (CaCl₂) is a food-grade mineral salt used in DIY coffee water recipes to contribute calcium (Ca²⁺) and chloride (Cl⁻) ions without adding alkalinity. It is water-soluble, widely available in food-grade form, and provides permanent hardness — the calcium and chloride remain dissolved on heating and do not form scale at normal brewing temperatures. In coffee water recipe design, calcium chloride is used alongside magnesium sulfate (Epsom salt) to build a balanced mineral profile: magnesium drives extraction efficiency and brightness, while calcium and chloride contribute body, mouthfeel, and sweetness enhancement.

Chemical Properties¶

Formula: CaCl₂ (anhydrous) or CaCl₂·2H₂O (dihydrate, more common in food-grade forms)
Molecular weight: 111.0 g/mol (anhydrous); 147.0 g/mol (dihydrate)
Solubility: Highly soluble (~74 g/100 mL water at 20°C); dissolves completely and quickly
Calcium content (anhydrous): 36.1% Ca by mass → 1 g anhydrous CaCl₂ = 361 mg Ca²⁺
Calcium content (dihydrate): 27.2% Ca by mass → 1 g CaCl₂·2H₂O = 272 mg Ca²⁺
Chloride content (anhydrous): 63.9% Cl by mass

Effect on Coffee Water¶

Calcium (Ca²⁺) contribution: - Adds hardness (body, crema stability) without bicarbonate or alkalinity - Contributes to extraction but is less efficient than Mg²⁺ for brightness compounds - Does not form scale at brewing temperatures (permanent hardness)

Chloride (Cl⁻) contribution: - Chloride at low concentrations (<30 mg/L) enhances perceived sweetness, roundness, and body - At higher concentrations (>100 mg/L), contributes to harshness or metallic character - See Chloride in Coffee Water for optimal levels

Use in DIY Water Recipes¶

Calcium chloride is most commonly used as a paired ingredient with magnesium sulfate (Epsom salt) and a bicarbonate source (potassium bicarbonate or magnesium bicarbonate concentrate) to create a balanced water recipe.

Example: Simplified mineral addition to 1 litre of distilled or RO water: - Epsom salt (MgSO₄·7H₂O): to target ~20 mg/L Mg²⁺ - Calcium chloride (CaCl₂·2H₂O): to target ~15 mg/L Ca²⁺ - Potassium bicarbonate: to target ~30–40 mg/L alkalinity as CaCO₃

Because both Epsom salt and calcium chloride are highly concentrated, working from stock concentrations (e.g., 0.1 g/L solutions diluted to precise volumes) is the practical approach.

Safety and Sources¶

Food-grade calcium chloride is safe for consumption at the concentrations used in coffee water recipes. Common sources: - Food-grade pickle crisps (calcium chloride pellets for pickling and cheesemaking) - Laboratory chemical suppliers (reagent grade) - Brewing supply shops (sold for cheesemaking and brewing)

Industrial or road-grade calcium chloride contains contaminants and must not be used in food applications.

Key Facts¶

Calcium chloride (CaCl₂) contributes Ca²⁺ and Cl⁻ to coffee water; does not add alkalinity; does not form scale
Used in DIY water recipes paired with Epsom salt (for Mg²⁺) and a bicarbonate source (for alkalinity)
Ca²⁺ contributes body and crema stability; Cl⁻ at low concentrations (~15–30 mg/L) enhances sweetness and body
Food-grade calcium chloride only — industrial/road-grade is not safe for consumption
Most DIY water recipes work from diluted stock solutions to achieve precise mg/L targets

References¶

Changelog¶

Date	Change
2026-04-28	Note created

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