Most brands of maple jugs are at full level when you stop filling at the bottom of the flare that's just below the threads, when filled at 180 degrees. If you are using a maple jug, stop filling at or slightly above that flare under the cap threads. If you are using any other jug you need to take a jug that is full hot (180-190F) and see where it gives you the amount you want. I fill mine to half way between the lower flare and the bottom of the threads, I use Sugarhill jugs. Before you can weigh them you need to know your scale is accurate, generally done by a certified scale. Giving away 4-6 oz is far better than cheating a customer out of even 1/2 oz. Get closer to the 3-4-6 oz extra is my suggestion.
If your scale is not certified you are taking a big risk, but try weighing something in your shopping cart that adds up to 11# on their scale. Then at home take the exact same group and weigh them on your scale to compare. Remember, you want slightly more.
For my syrup I finish it at 66.9 and fill as I described above. If all are packed at 180 F but the densities vary from lets say 66.5 up to 67.4, the weights for an official gallon will vary too. More sugar= more weight.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.