Testing Alcohol content in homebrewed wine?

Question

is there a way to fine out the alcohol content of homemade wine?

Answer 1

The easiest method involves testing it before it ferments and then after it ferments. You use a hydrometer to measure the relative content of sugar (which is proportional to alcohol production).
You will have less at the end, so you take the final reading and subtract it from the first reading and it tells you how much sugar was converted to alcohol.

If the wine is already done and you have no idea how much is in there, it requires specialized testing procedures that can only be done in labs...the sample is essentially distilled and the alcohol content is measured. This way is actually a lot more precise than the hydrometer method, but only used for taxation purposes for commercial wineries and breweries.

Answer 2

You can only do this with a hydrometer. You have to first take a reading of the density before fermentation I just grab a sample before I put it in the carboy. The hydrometer measures the amount of dissolved sugar compared to plain water, this is called potential alcohol. You then take various readings throughout fermentation to see how much sugar has not been consumed and adjust accordingly. When the hydrometer reading is satisfactory you are then ready to bottle. There is an ancient method of using an egg to measure potential alcohol but I have no clue as to how it works Similar to using a hydrometer as the egg will float in dense liquid I just do not know exactly how it works, might be fun to experiment though

Answer 3

You will need to measure the specific gravity before frementing, then after fully fermented. For this I have a 'triple scale hydrometer'. As the yeast turns sugar into alcohol by consuming it, the liquid becomes less dense, and the hydrometer, which has graduated markings on the side, will float lower. I used this for my homemade beer, but decided it wasn't worth the effort. The reason for testing beer was to make sure it was fully fermented before bottling, to avoid bottles exploding. Visually I could tell what was going on in a glass carboy secondary fermenter, and could wait an extra day or two to make sure it fully fermented out. My beer brewing guide had a mathamatical formula for converting the hydrometer reading difference along with temperature readings into alcohol content. Too much trouble for me

Answer 4

Use your hydrometer to read your specific gravity or Briggs of the final fermented wine. The 21% sugar reading is 21 Briggs, and on a proper hydrometer will relate to what your SG is @ 21 briggs, and gives you a possible ABV of 10.5% alcohol by volume. That is depending on what your final gravity reading/ sugar percentage is. Measure that final reading, and subtract it from the original estimated amount of 21 briggs/ 10.5% possible abv, and that will give you the final alcohol content.