Potassium Carbonate 2 oz
Potassium carbonate is generally used as a less aggressive deacidification method than calcium carbonate. It reduces acidity through precipitation and neutralisation (much like calcium carbonate), and about 30% of potential acid reduction occurs through precipitation during cold stabilisation.
Potassium carbonate can react with malic acid to form potassium bimalate. However, potassium bimalate is soluble in wine and will not (or may be difficult to) precipitate out.
It is usually added to the entire batch of wine, and CO2 is released while the batch is well mixed. Cold crash after 1-2 weeks to help encourage precipitation, then rack off of the newly formed salt lees.
Directions: use 3.8 grams/gallon to reduce acidity by 0.1%.
QUESTIONS & ANSWERSAsk a Question
How to use it to reduce malic acid (in hard apple cider).
Added at 3.8 grams per gallon, this will reduce over all acidity by making the acids precipitate out of solution. To specifically reduce malic acid, you will want to use a malolactic bacteria, which you pitch into the cider after fermentation and allow 2 - 4 weeks for it to turn the malic acid into lactic acid.