Every drop of syrup that I produce, (1,243 gal in 2020) is checked with a hydrometer and a thermometer in about 6 gallon batches before the syrup is put through the filter press and then into SS barrels. After drawing off 6 gallons into a 7 gall SS pot, I place the pot on a propane burner set up, bring the temperature of the syrup up to 211 degrees and then check the density with my hydrometer. If the syrup is too heavy, I add hot sap to reduce the density to the hydrometer 211 red line.
I have an automatic draw off that I set the draw off temperature on before each day's boil after checking the barometric pressure. I always set the draw off temperature a few tenths of a degree higher than my barometric pressure draw off temp chart that I made up. (To make sure that the initial draw of syrup is not too light) Once in a while, the only time the syrup is under density, is the first draw of the day's boil if I goof up the initial temp setting. If the initial draw syrup is too light, I just boil it a little on the propane burner to bring it up to density.
Using this method also insures that all my syrup is started through the filter press at about 210 degrees.
Joe
2004- 470 taps on gravity and buckets
2006- 590 taps on gravity and buckets 300 gph RO
2009- 845 taps on vacuum no buckets, 600 gph RO
2010- 925 taps on vacuum new 2 stage vacuum pump
2014- 3045 taps on vacuum, new 1200 gph RO
2015- 3104 taps on vacuum
2017- 3213 taps on vacuum
3' x 10' oil fired evaporator with steamaway