Hydrometer
Handle your hydrometer with care. Draw off a sample of liquid to be tested into a trial jar. Gently lower the hydrometer into the liquid until it floats freely. Spin the hydrometer to eliminate any air bubbles clinging to the side as if this is not done a false reading can be obtained. When the hydrometer has stopped moving and is not in contact with the sides or bottom of the trial jar, take reading as shown on the diagram. This hydrometer is calibrated to give correct readings at 20°C/68°F.
Regular use, the beer hydrometer will enable you to follow the progress of fermentation. As the sugar turns into alcohol, the hydrometer will slowly sink. When fermentation is complete, the hydrometer will stop sinking. Starting Sp.Gr. could vary from 1.030 to 1.064. Beer can be bottled when the Sp.Gr. is between 1002 and 1008. To help the beginner colored brands mark the scale. Sterilize all equipment to be used for testing your beer before starting.
HOW TO ESTIMATE THE APPROXIMATIVE POTENTIAL % ALCOHOL CONTENT To calculate the approximative potential Alcohol content of your beer, measure the Specific Gravity of the liquid before fermentation has started, and simply note the equivalent reading on the potential alcohol scale.
EXAMPLE 1
INITIAL SP.GR: 1.090 = 11.8 (before fermentation)
FINAL SP.GR: 1.010 = 1.3 (after fermentation)
Alcohol approximate is = 10.5% vol (= 11.8-1.3)
EXAMPLE 2
INITIAL SP.GR. : 1090= 11.8 (before fermentation)
FINAL SP.GR.:0.995 = 0.7 (after fermentation)
Alcohol approximate is = 12.5% Vol. (= 11.8+.0.7)