Dec 2017
Specific Gravity
December, 2017 Filed in: Wine making
What is S.G. and why is it so important?
Specific Gravity (S.G.) is the winemaker’s compass reading – it can tell us where the wine is in its fermentation process and is very important to stay on track and not get lost along the way. You may remember from a previous article, new yeast sub-strains used in your wine kits do not cause excessive foam like we used to find years ago. With this in mind we can no longer rely on visual signs, but need t rely on the S.G. reading.
How do we get these readings?
Through a device called a hydrometer.
How does it work?
A hydrometer measures the density of liquid. As sugar in the wine is replaced by less dense alcohol (the job our trusty yeast friends are busy doing), a lower reading is given on the hydrometer. Using this information, you will be able to know if your wine is fermenting and when fermentation is complete. Once the S.G. does not change, the S.G. will remain constant over a few days. It is important to realize that the S.G. of pure water is 1.000, so wine juice being more have a higher number (usually 1.08 to 1.10 for most wines) and as the sugars are converted to alcohol, yeah!, the wine becomes less dense than water. The S.G. of pure alcohol is 0.787.
Specific Gravity (S.G.) is the winemaker’s compass reading – it can tell us where the wine is in its fermentation process and is very important to stay on track and not get lost along the way. You may remember from a previous article, new yeast sub-strains used in your wine kits do not cause excessive foam like we used to find years ago. With this in mind we can no longer rely on visual signs, but need t rely on the S.G. reading.
How do we get these readings?
Through a device called a hydrometer.
How does it work?
A hydrometer measures the density of liquid. As sugar in the wine is replaced by less dense alcohol (the job our trusty yeast friends are busy doing), a lower reading is given on the hydrometer. Using this information, you will be able to know if your wine is fermenting and when fermentation is complete. Once the S.G. does not change, the S.G. will remain constant over a few days. It is important to realize that the S.G. of pure water is 1.000, so wine juice being more have a higher number (usually 1.08 to 1.10 for most wines) and as the sugars are converted to alcohol, yeah!, the wine becomes less dense than water. The S.G. of pure alcohol is 0.787.