Do I need to treat my water?

If your tap water contains chlorine or chloramine (most UK water supplies do), you should treat it. Chlorine/chloramine reacts with phenols from malt to create chlorophenols, which taste like plasters or TCP — even in tiny amounts.

How do Campden tablets work?

Campden tablets contain sodium or potassium metabisulphite. Half a tablet treats 20 litres of water instantly, neutralising both chlorine and chloramine. It is the simplest and most effective water treatment for homebrewing.

Can I just boil the water instead?

Boiling removes free chlorine but does NOT remove chloramine, which is increasingly used by UK water companies. Campden tablets remove both. Always use Campden if your water company uses chloramine.

Why do I need to treat my water?

Chlorine and chloramine in tap water react with phenols from malt to produce chlorophenol off-flavours (medicinal, plasticky taste). Even small amounts are detectable. One Campden tablet per 60L removes both chlorine and chloramine instantly.

Is a carbon filter sufficient for water treatment?

A carbon filter removes chlorine but is less effective against chloramine. Many UK water utilities use chloramine. Campden tablets are more reliable for chloramine removal. A carbon filter plus Campden tablet provides the most thorough treatment.

BrewCalcs

Water Treatment Calculator

Calculate Campden tablet and other water treatment additions.

Water Volume

Treatment Type

How We Calculate This

Water Treatment

Campden tablets: 1 tablet per 20 litres. Crush and dissolve in your brewing water. Treatment is instant — no waiting required. This removes chlorine and chloramine without affecting water chemistry.

Frequently Asked Questions

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Last updated: 2025-02-20

All calculations are estimates. Always verify values and adjust based on your equipment and ingredients.