Magnesium Sulfate (MgSO₄) - Brewing Water Treatment & Mineral Addition
Magnesium Sulfate (MgSO₄), commonly known as Epsom salt, is a food-grade brewing water mineral used by homebrewers to fine-tune water chemistry and dial in the mineral profile that specific beer styles demand. Supplied in a practical 100g pack, this highly soluble powder dissolves completely and immediately in brewing water, strike water, or directly in the mash — giving brewers precise, repeatable control over magnesium and sulfate ion concentrations in every batch.
What makes MgSO₄ a useful addition to the homebrewer’s water chemistry toolkit is its dual mineral contribution. The sulfate ion (SO₄²⁻) accentuates hop dryness and bitterness perception, working in concert with calcium sulfate (gypsum) to build the crisp, mineral-edged hop character that defines Burton-on-Trent pale ales, West Coast IPAs, and dry, bitter lager styles. The magnesium ion (Mg²⁺) acts as a yeast nutrient at low concentrations, supporting healthy fermentation — though at elevated levels magnesium contributes an unwanted harsh, astringent bitterness, so precise dosing against a target water profile is always recommended over casual addition.
Used thoughtfully alongside other brewing salts — calcium sulfate, calcium chloride, and sodium chloride — magnesium sulfate gives homebrewers the granular control over water chemistry that separates good beer from beer that is genuinely built for its style.
Powder form
Supplied as a fine, free-flowing powder. Dissolves quickly and completely in cold or warm brewing water without pre-treatment.
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Key Features
• Food-grade magnesium sulfate (MgSO₄) — Epsom salt
• Dual mineral contribution — sulfate (SO₄²⁻) and magnesium (Mg²⁺) ions
• Accentuates hop dryness, bitterness perception, and mineral character
• Supports yeast health as a magnesium nutrient source at low doses
• Highly soluble — dissolves instantly in brewing water
• 100g pack — sufficient for multiple water treatment additions
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Usage
Best suited for: Water profile adjustment for hop-forward styles, Burton-style pale ale water profiles, West Coast IPA and APA mineral builds, yeast nutrient supplementation
Typical styles: West Coast IPA, American Pale Ale, Burton Pale Ale, Bitter, dry lager styles
Dose: Add to strike water or mash according to target water profile. Always calculate additions against your base water report using brewing software.
Note: Elevated magnesium levels (above ~30 ppm) can contribute harsh bitterness and a laxative effect at high consumption. Keep within recommended water profile targets.
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Quick facts
Product: Magnesium Sulfate
Chemical formula: MgSO₄
Common name: Epsom salt
Form: Fine powder
Pack size: 100g
Ion contribution: Sulfate (SO₄²⁻) + Magnesium (Mg²⁺)
Use: Water chemistry adjustment, hop accentuation, yeast nutrition