Misc addition
Potassium Metabisulfite
Representative The maker publishes no figures for this product, so these are class-typical values instead.
- Type
- Water treatment
- Added at
- packaging
- Form
- powder
- Formula
- K2S2O5
- Concentration
- sold as the pure compound
- Typical dose
- 0.05-0.1 g/L for stabilizing
- Timing
- At packaging for stabilizing, or in the liquor a day ahead for chloramine.
Before you use it
Chosen over the sodium salt wherever the beer already carries enough sodium, since the potassium contributes nothing to flavor at these doses. Weigh it rather than measuring by spoon.
Description
The pure salt rather than a pressed tablet, which is what makes an accurate small dose possible: a Campden tablet is a fixed 0.44 g and a fraction of one is guesswork. Used to stabilize before back-sweetening, and to strip chlorine and chloramine from brewing liquor.