Measuring the alcohol content of wine after fermentation
Of course, if you've taken proper hydrometer readings, you can calculate the amount of alcohol formed in your wine. But if you haven't got one or want to check your calculations, you can use a vinometer. But there is one mayor restriction: A vinometer can only produce accurate results in a dry wine (containing little or no residual sugar). The vinometer works on the principle of capillary action, so it actually measures viscosity, which is dependant on the alcohol/ water ratio. It has a scale of alcohol content marked on it.
The procedure goes as folllows
- Fill the vinometer with some dry wine.
- Wait until some drops have fallen through and drip out the bottom. If the wine doesn't start to flow on its own, put your mouth on the funnel-side of the vinometer and blow gently.
- Then put a finger on the part where the drops form and turn it upside down.
- Place the vinometer on a straight surface. You might want to place it on a small plate to avoid making a mess.
- Release the finger. The level in the capillary will drop to a certain level, which indicates the alcohol content of the sample (the arrow).
- Take two more measurements and take the average value of the measurements:
Average = (Measurement 1 + Measurement 2 + Measurement 3) / 3
- Clean the vinometer and store it away.
A more specific reading can be obtained by mixing 5mls of wine to 5mls of water and proceeding as above. Your final reading should be multiplied by two to give the alcohol percentage. e.g. If the vinometer shows 5% then your wine should have an alcohol percentage of 10%
There should not be any air bubbles in the tube
Clean and dry the vinometer carefully before and after use.