DSOS: = Dissolved Solids Other than Sugar - note that if your density reading is from a hydrometer, using a value for DSOS is more important, if the reading is from a refractometer, you can probably assume no DSOS.
Details: This calculator works out how much sugar to add to a given volume of wine to raise it to a desired density (which we use as a measure of sugar content). For convenience it also calculates the estimated potential alcohol of the current must, and after the calculated chaptalisation. The estimated finishing gravity and correction for DSOS can be ignored if alcohol prediction is not required.
The alcohol calculation carried out here is identical to that carried out in the 'Alcohol Prediction (pre-ferment)' section.
The chaptalisation calculation is based on calculation of dissolved solids (grams per litre) as discussed in the 'Gravity/Density/Sugar Conversions' section. The difference between the desired and the current values is then simply multiplied by the number of litres to be chaptalised.
VinoCalc by Jonathan Musther - email@example.com