Does this sound like a good idea?
Say I use a refractometer/hydrometer to get a reading of SG 1.057 from some fresh pressed apple cider. That means the density of the cider sample is 1.057 times the density of water(1kg/liter), correct?
Fructose is the primary sugar in cider. We want to prime a 5 gallon batch with about 5.25 oz of corn sugar(dextrose/d-glucose) at 60 degrees to get 3 volumes of CO2(seems like a decent carbonation level for a sparkling cider).
Molar mass of dextrose is 180.16 g/mol
Molar mass of fructose is also 180.16 g/mol
meaning we would want to use 5.25 oz of fructose as well.
5.25 oz in kg = 0.15 kg
d = m/v
v = m/d
v = 0.15/1.057
v = 0.14 Liters, or 0.6 cups of cider should contain 5.25 oz of fructose and be suitable for priming a 5 gallon batch... right?
I think I'm missing something here