I've just been using the brewcraft sg estimator to see what effects different ingredients have on the gravity and alcohol concentration.One of my readings was 1046 sg and 1013 fg with an alcohol level of 5.5 percent.I then ran these figures through the chart that came with my hydrometer and with the same gravity readings came up with 3.9 percent alcohol! Which of these is correct,and ,also,is there a formula for working out alcohol percentage from sg and fg?Thanks. <_<