Most wines fall around a pH reading of 3 or 4. For white wines, a desirable reading is a pH of approximately 3.2, while the best pH for red wines is around 3.6.
It is important that the acidity of the juice has the correct pH. The ideal pH reading for cider is between 3.2 – 3.6. A weaker acid content of pH 4.0 or above can lead to flavour problems and make the juice more prone to bacterial infection.
If your juice has too much acid, you will need to reduce it so that you get a nice healthy fermentation and have a better tasting drink.
Acid Reducer is a fine powder of Calcium Carbonate (Precipitated Chalk) that is added to the Wine or Cider, at a starting rate of 1g per litre. This will reduce the acidity by around 1.5 ppt (part per thousand). When added, it will release CO2 (carbon dioxide) as a gas as it neutralises the acid and it may also foam up, so ensure there is sufficient head space in the container before adding. Sometimes this can also produce a sediment as the acid is neutralised so if added to a finished Wine or Cider, leave it in a cold place for one week to allow any acid crystals to fall out as a sediment.