Estimatation of alcohol by specific gravity method
This method provides an approximation of alcohol content. Specific gravity is the density of a substance relative to the density of water or it is the ratio of density of a substance compared to the density of fresh water at 4°C (39° F). At this temperature the density of water is at its greatest value and equal 1g/ml. Since specific gravity is a ratio, so it has no units. An object will float in water if its density is less than the density of water and sink if its density is greater than that of water. Similarly, an object with specific gravity less than 1 will float and those with a specific gravity greater than one will sink. Specific gravity values for a few common substances are: Au-19.3; mercury-13.6; alcohol-0.7893; benzene- 0.8786. Note that since water has a density of 1g/cm3, the specific gravity is the same as the density of the material measured in g/cm3. The method assumes that the difference in Specific Gravity before and after fermentation is due solely to the conversion of sugars before fermentation into alcohol after fermentation.
* The method relies on –
all the wines measured, starting with the same sugar levels
all the sugars being fermented, with the wine finishing dry
the unfermentable sugars being the same for all wines
The method assumes that the difference in Specific Gravity before and after fermentation is due solely to the conversion of sugars before fermentation into alcohol after fermentation.