Testing for Alcohol

This week we will be topping up the French Oak barrels.
We'll also take a final specific gravity reading so we can calculate the alcohol content by volume. If the wine is dry (should be) then we may get a vinometer to produce a more accurate result.
We've also heard that if you think your initial specific gravity reading, taken when you first crush, is accurate enough then a very accurate way to tell how much alcohol you have left is to now test the wine using one of those test kits that diabetics use. The kit will measure very accurately the sugar content. You then take this result from the initial potential sugar content from your first specific gravity reading and Bob's your Uncle, you have your final alcohol content.
For example, if your initial specific gravity reading shows a potential alcohol content of 15% (assuming all sugar is burned up), then a diabetic test result showing 3% residual sugar in your wine gives you a 12% alcohol content.