I read this somewhere and tried it - seems to work. Because the sulfite test strips don't work with red wine you can try this. I used the quontofit test strip. Take an once of red wine add a teaspoon of citric acid (got mine in Wild by Nature). Hold the strip above the solution for 5 minutes I bent my strip over a shot glass and covered it with tinfoil. The color will change on the test strip due to the gas that is given off. It's not accurate down to the ,10 but it will give you an idea of how much sulfite is in your red wine.