text: The Ripper Method, developed in 1898, is an analytical chemistry technique used to determine the total amount of sulfur dioxide (SO) in a solution. This technique uses iodine standard and a starch indicator to titrate the solution and determine the concentration of free SO. The titration is done again with a new sample of the solution, but the sample is pretreated with sodium hydroxide (NaOH) to release bound SO. The result of these two titrations can then be used to determine the bound, free, and total amount of SO in the solution. Instead of using a starch indicator, an electrode can be used to determine the presence of free iodine. This technique is widely used in wine making.