# Double Salt Deacidification

Current TA (g/L equiv. tartaric)
Target TA (g/L equiv. tartaric)
Volume of wine/juice (L)
Minimum volume to treat* (L)
Recommended volume to treat* (L)
Mass of calcium carbonate** (kg)

Details:  This calculator calculates the volume of wine to treat, and the mass of calcium carbonate (CaCO3) required to treat it for double salt deacidification.

* The minimum volume to treat is the technically smallest volume of wine which needs to be completely deacidified.  Allowing slightly more wine than this is the normal practice, as it ensures that the required deacidification is completed.  The recommended volume to treat is simply 5% greater than the minimum, and is roughly in accordance with the volumes provided by the makers of Acidex®.

** Calcium carbonate (CaCO3) is the deacidification agent.  Brand name agents such as Acidex® consist almost entirely of calcium carbonate, but are seeded with crystals of the double salt, calcium malate-tartrate, designed to encourage precipitation of this salt.  The mass calculated here can be used in either case.

Tip:  If you are treating a small volume, enter 1000 times the volume you have and the output will be in grams.  For example, to deacidify 15 litres, type 15000 and the mass output will be in grams.

Double salt deacidification is somewhat more complex than simple deacidification.  A portion of juice is removed and completely deacidified, that is, unlike with simple deacidification, tartaric and malic acid are removed.  This portion is then blended back to the bulk of the wine to have the desired effect.

The volume to treat is calculated with the following formula:

volume (L) = ( ( current TA - target TA ) * total volume ) / current TA

The recommended volume to treat is this minimum technical volume multiplied by 1.05.

The following formula is then used to calculate the mass of calcium carbonate (or Acidex® etc):

mass (kg) = ( ( current TA - target TA ) * total volume ) * ( ( 1 / 150.087 ) / 10 )

Where:
150.087 = the molecular mass of tartaric acid
10 = is simply a conversion to make the mass express in kg

VinoCalc by Jonathan Musther  -  jon@musther.net