You have just finished fermenting a wine and the pH = 3.7. You need 2mg/L "molecular" SO2 to protect the wine. What level of free SO2 do you have to add to achieve the level of the molecular form desired? You can ignore the sulfite(SO3) form at this pH as the levels will be negligible. Perform by calculation and give answer in mg/L.
SO2(molecular form) <==> HSO3- + H3O+
pKa = 1.89
I know that Free [SO2] ~ [HSO3] and
Molecular [SO2] mg/L = FSO2 mg/L * 10 pK-pH
Molecular [SO2] mg/L = [FSO2] / 10pH - pK© BrainMass Inc. brainmass.com March 4, 2021, 6:20 pm ad1c9bdddf
The solution provides detailed explanations and step-by-step solutions for finding the levels of sulfur dioxide requires to protect fully fermented wine.