Titration Kits

From James K. Moseley

The cheapest and easiest way is to buy the titration kits which measure free SO2 as opposed to total SO2. These titration kits use the Ripper method for determining the amount of free SO2. Because it is hard to read the titration end-point in red wines, dilution of the sample is required and the accuracy is probably no better than 10 to 20 mg/L.

Total SO2 can be computed by knowing the amount of sulphite you've adding during the winemaking process. If you added 50 mg/L at crush, 50 mg/L at first racking, and 50 mg/L at bottling, you should have roughly 150 mg/L total SO2 in your bottled wine. There will be some error due to evaporation and other considerations.

Other very accurate means exist to measure both free and total SO2 using vacuum aspiration. Conducting the analysis is not that difficult, especially if you taken high school or college chemistry, but the chemicals and labware needed to perform the analysis can cost hundreds of dollars.

Jon Iverson's book documents the vacuum aspiration model. You can also buy complete labware setups from companies such as Vinquiry.