How to read a hydrometer 
   
on this page:
1.  Reading a hydrometer.
2.  Chart for brix, specific gravity and potential alcohol. 
3.  Chart for temperature adjustment at 68 degree F.
4.  Instructions for use of Fermtech hydrometer jar/wine thief.

                             Fall Bright, The Winemakers Shoppe

            BEFORE you begin fermentation, please take a hydrometer reading.  A stable wine has 9 – 14 percent alcohol.  In order to achieve this level of alcohol, the juice or fruit to be fermented must have an adequate sugar level.  General conversion of sugar to alcohol is approximately 58% (0.575%~).  A brix of 21 degrees yields around 12% alcohol. 
           View the hydrometer floating in the juice sample at eye level.  Take the reading from the bottom of the meniscus (see illustration below).  The balling/ brix scale is the brix or sugar percentage.  In addition to the brix scale, a triple scale hydrometer offers a scale for specific gravity and one for potential alcohol.

                 

   

TEMPERATURE ADJUSTMENTS:  Most hydrometers are calibrated for a sample of a certain temperature and will give adjustment factors in with their instructions. 

Brix test is a measurement of dissolved solids in a juice/wine being tested.  Should there be any alcohol in the wine sample, the test would be properly called a Balling.  The actual testing procedure is, however, identical.  

1.  Adjust the temperature required as indicated on the hydrometer stem.  If the sample contains any carbon dioxide gas, the gas should be removed by careful agitation.  

2.  Pour sample into clean and dry hydrometer jar up to about 2 inches from the top.  If your jar is not dry, rinse it with some of the juice.

3.  Insert clean and dry hydrometer, holding the top of the hydrometer stem in a pendulum effect.  

4.  Spin the hydrometer in the sample.

5.  Read the instrument at the bottom of the meniscus (see illustration above).

6.  Retake temperature immediately and make necessary adjustments. 

Chart:  figures from Commercial Winemaking by Vine

Brix at: 20 degrees C 68 degrees F   Specific Gravity   Potential  Alcohol     -5     -4     -3     -2     -1     0   1.0000   0.0000 1   1.0039   0.575 2   1.0078   1.150 3   1.0117   1.725 4   1.0156   2.300 5   1.0196   2.875 6   1.0236   3.450 7   1.0277   4.025 8   1.0318   4.600 9   1.0359   5.175 10   1.0400   5.750 11   1.0441   6.325 12   1.0483   6.900 13   1.0525   7.475 14   1.0538   8.050 15   1.0610   8.625 16   1.0653   9.200 17   1.0697   9.775 18   1.0740   10.350 19   1.0784   10.925 20   1.0829   11.500 21   1.0873   12.075 22   1.0918   12.650 23   1.0963   13.225 24   1.1009   13.800 25   1.1055   14.375 26   1.1101   14.950 27   1.1148   15.525 28   1.0095   16.100 29   1.1242   16.675 30   1.1290   17.250 31   1.1338   17.825 32   1.1386   18.400 33   1.1435   18.975 34   1.1484   19.550 35   1.1533   20.125 36   1.1583   20.700 37   1.1633   21.275 38   1.1683   21.850 39   1.1734   22.425 40   1.1785   23.000 41   1.1837   23.575 42   1.1888   24.154