Hi all. First time wine maker with a Portuguese family. Blend of red and white grapes (local harvesting) I have about 14 gallons in a demijohn in the garage. I bought a hydrometer ton check alcohol content but unfortunately I didn’t realize you need to measure before fermentation begins, and after. So i think it’s too late to use it, as it’s been fermenting for about a week already. Is there another way I can check alcohol when it’s done fermenting? Maybe in another month or so?
Help Support Homebrew Talk:
bernardsmith
Well-Known Member
Hi rk4810 and welcome. Interesting question.
There is a method of estimating the alcohol content of a wine or beer even if you do not know the starting gravity. You measure the "actual" amount of alcohol in solution, but to do this you need to sacrifice a small amount of your wine.
Four steps.
1. Take a gravity reading of your wine today.
2. Pour a known volume of the wine into a beaker (say, 200 ml) and boil this until you have boiled off 100 ml. You will have boiled off all the alcohol (and some of the water).
3. Replace the lost volume (in this example, 100 ml) with distilled water. Measure the gravity of your 200 ml of solution. Because alcohol is less dense than water, the SG will have risen.
4. Subtract your first reading from your second and apply the number to the calculator found here: VinoCalc - by Jonathan Musther. This will convert the number to the ABV.
Good luck
There is a method of estimating the alcohol content of a wine or beer even if you do not know the starting gravity. You measure the "actual" amount of alcohol in solution, but to do this you need to sacrifice a small amount of your wine.
Four steps.
1. Take a gravity reading of your wine today.
2. Pour a known volume of the wine into a beaker (say, 200 ml) and boil this until you have boiled off 100 ml. You will have boiled off all the alcohol (and some of the water).
3. Replace the lost volume (in this example, 100 ml) with distilled water. Measure the gravity of your 200 ml of solution. Because alcohol is less dense than water, the SG will have risen.
4. Subtract your first reading from your second and apply the number to the calculator found here: VinoCalc - by Jonathan Musther. This will convert the number to the ABV.
Good luck
