Precipitated Chalk (Calcium Carbonate) 100g
More commonly known as Precipitated Chalk, it has the opposite effect from Calcium Sulphate.
The carbonate increases the pH of the mash, (that is to reduce its acidity), and its use is normally limited to the making of dark beers with high levels of roasted grains, such as stouts.
Calcium Carbonate is also used to reduce the acidity of wines.
The addition of 7 grams to one gallon (4.5 litres) of wine will reduce the acidity by approximately 1.5 grams per litre.
The reaction will give off carbon dioxide which may cause foaming, and it will also throw sediment.
Also used in Cider making to reduce the effects of high Malic Acid (acidity).
Best added to the must when making wine before primary fermentation.