• Magnesium Sulphate (Epsom Salts) 100g – main product photo
  • Magnesium Sulphate (Epsom Salts) 100g key facts: pack size: 100g, 1g in 23L adds 4ppm Mg, 17ppm SO4, keep total magnesium under 30-50ppm
1 2

Harris

More from Harris

Magnesium Sulphate (Epsom Salts) 100g

Magnesium Sulphate (Epsom Salts) 100g

£1.29
£1.29
Sale Sold out
Taxes included. Shipping calculated at checkout.
View full details

Magnesium Sulphate (Epsom Salts) is a brewing water salt used in small amounts to adjust the mineral profile of your mash and sparge water. It supplies magnesium, which yeast needs, and sulphate, which sharpens hop bitterness for a crisper, drier beer.

Key benefits

  • Adds magnesium and sulphate to your brewing liquor
  • Brings out hop character - useful in pale ales, bitters and IPAs
  • Supports yeast health in soft or low-mineral water

Specs

  • Pack size: 100g
  • Also known as: Epsom salts

How to use

Work out your addition from your source water and target profile - too much can taste harsh. Dosing guidance is in the How to Use box below.

Pairs well with

For all-grain brewers fine-tuning their water for hop-forward beers.

Magnesium Sulphate (Epsom Salts)
How to Use
Dose
A few grams per 23L
keep Mg under 30-50ppm
1g in 23L adds
4ppm Mg, 17ppm SO4
Wine
½ tsp per 5L
with the yeast

Used for: Beer: adds sulphate (drier, crisper bitterness) without extra calcium, plus a little magnesium for the yeast. Wine: a small dose works as a yeast nutrient.

When: Beer: in the mash or strike water. Wine: at the start, with the yeast.

Step by step
1Beer: work out your target from your water report.
2Weigh it - each 1g in 23 litres adds about 4ppm magnesium and 17ppm sulphate.
3Dissolve in the strike water or add at mash-in and stir well.
4Wine: dissolve ½ teaspoon per 5 litres in a little warm must and add with the yeast.
Good to know: Keep total magnesium under about 30-50ppm - more tastes harsh and can be laxative. Most UK tap water already has some magnesium - check your water report.
You may also need: Gypsum · All treatments & water salts
Frequently Asked Questions
How much Epsom salt for 23 litres of beer?

Usually just a few grams. Each gram adds about 4ppm magnesium and 17ppm sulphate - keep total magnesium under about 30-50ppm.

Gypsum or Epsom salts?

Gypsum adds calcium and sulphate. Epsom salts add sulphate without extra calcium, plus a little magnesium.

How do I use it in wine?

½ teaspoon per 5 litres of must, added with the yeast - it works as a yeast nutrient.

Can I use bath Epsom salts?

No - only food-grade magnesium sulphate with no fragrance or additives.