SO2 Testing

I bought the Midwest SO2 testing kit and I'm starting to wonder how accurate the results are so I tested some "store bought" wine. The 2006 Italian Chianti showed zero, I mean zero, the $2 (actually it was $3 bucks) buck chuck showed about 8-10ppm, some two year old white wine from a local commercial vinter showed less than 10ppm. I don't know what do you make of this? I wish I had some buffer solution to test my SO2 tests. bk

Exactly what kit did you buy? Is it a aireation /oxidation kit?

LOL, yes what is a Midwest SO2 test kit!

It is the Master Vinter Aeration Oxidation Free SO2 Testing Kit from Midwest Supplies, $99.99

What does LOL mean? bk

Ok that test should give you a very accurate reading. I was just wondering if you were using titrets from Hanna.

I'm going to call Midwest tomorrow and ask why their instructions say to use 3% H2O2 but the Valley Vinter dilutes the H202 to .3%. bk

I put together my own aeration-oxidation system using several documents on the Internet and the information provided by "The Homebuilt Winery" book. They all list 3% H2O2.

homer: lol = laugh out loud

Spoke with the Valley Vinter today about his You Tube video on So2 testing, his first question was, am I testing for total So2 or free So2, OK I give, with my testing equipment what am I testing for? bk

Huh....I was under the impression you needed to spend several hundred dollars to test so2 levels. I wrote off testing so2 as too expensive but this might change that. Any reviews on accuracy are appreciated.

Your testing for free SO2 if your test is aeration/oxidation. You can use plain old peroxide from the store. What you need to do is only order small amounts of NaOH as needed 100ml, not 1000ml as it does have a shelf life.

No, you don't have to spend hundreds of $$ to test for SO2. More Wine has one as well for ~$100 same thing aeration/oxidation. This is one of the most accurate test out there but it does have a learning curve. More Wine has some excellent videos as well on You Tube.

Agree with Mike, there is a learning curve. Best to make up a stock solution of a known value and then run some test until you get the right results.

Also good to keep chemicals refrigerated.

Homer - I have the same testing kit and wondered how accurate the results were too. I made up a control solution, targeting 35 ppm and kept getting results 1/2 or 1/3 as high as they should have been. Repeatedly. I couldn't figure out what was off.

Turned out my potassium metabisulfite was old. Once I switched to an unopened pack, I reached 30ppm.

Make sure you refrigerate your hydrogen peroxide and that you don't contaminate your solutions as you reuse pipettes...

Never thought about storing H2O2 in the ice box, will from now on. One trick I did to stop contamination was label the pipettes and always rinse out the 20ml with the wine I'm testing. bk