Sulfite Testing

[masta]

I recently purchased a sulfite testing kit (not titrets) and will be practicing with it soon and will post results. The big trick to testing red wine is to see the color change for an accurate result. I have acquired some equipment that should make this work well.


The procedure is the Iodometric Method, also known as the Ripper Method. It is based on the reaction of the free sulfite with potassium iodine-iodate standard.

 

[AAASTINKIE]

I see geo sells titrates, is that easier to use, especially if you are partially color blind? I get my browns and greens a little confused sometimes, the close shades that is.

 

[masta]

Based on the instructions that come with the Titrets and information from more experienced vintners than myself I chose not use them and buy a different kit.


They both work basically the same way but the difficult part is testing red/dark wines because you need to see a color change. I tested two batches with my new kit last weekend and think I got a fairly accurate number but want to work on the procedure and fine tune it.


It all could be overkill but us winemakers have lots of time to play


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.....and yes I will have to wash the glassware when I get done Edited by: masta

 

[Joseph1]

Masta,


I have heard that using a yellow bug light can help make the color change in red wine easier to see.


Joseph

 

[masta]

I bought a yellow light and tried it but seemed to make it harder to see the color change.....I will be working on this and let you know what i find.


Part of the problem also is having a constant mixing of thesample while adding the potassium lodide-lodate and counting the drops at the same time.

 

[MedPretzel]

I used the titrets for the first time a few weeks ago.





Well, all I can say is either I'm doing something wrong, or there's gotta be an easier way to measure that. I think, though, practice could help. Does anyone have hints to better control the process to see exactly when the color change takes place? (for me, all of a sudden I had tons of wine in the titret, and it was practically pitch black. I had to throw that one out (obviously) and try it again. I did better on the 2nd try, but not great. It was just so hard to control the "uptake")

 

[Hippie]

My only tip would be to half the wine sample with water and double the result, and use a yellow bug light.

 

[masta]

Good idea Country on diluting with water...I have gathered some more equipment to make my sulfite testing with new kit easier. I will be putting on my my lab coat later today and will post results.


George is working on bringing in the type of kit I purchased and we will be working together to provide this as an option for everyone to buy.

 

[Hippie]

Thank you very much George and Scott! Maybe even a section with step by step pics? This forum is getting cooler all the time!

 

[masta]

Update on sulfite testing: The kitI purchased works well and the yellow light helps see the color change when testing red wines. George sent me a Acidometer kit and Iodic (SO2) Solution that I am working with to see how the results compare to the kitI have.


The first couple of tests went well and when I am happy with the results after more testing I will post results and proper procedure that works.


Then y'all can place an order for your own kit!

 

[AAASTINKIE]

I'm going to have to do something about sulfite testing soon, I am just guessing where I am at on my welches wines.

 

[AAASTINKIE]

I was thinking about sulfite testing and we use sulfite in the boiler for an oxygen scavenger, I went over to the lab (I only worked there for 12 years doing this test) and we have a sulfite test there, right next to the bank of PH meters, I think a small sample of wine could come in for a test now and then.

 

[Hippie]

Very good idea, Stinkie. I am also a boiler operator here.

 

[MedPretzel]

I don't know. It just doesn't sound good to me.

 

[Hippie]

Testing sulphite in boiler water and testing sulphite in wine should be the same process.

 

[AAASTINKIE]

I brought a sample in with me today, it was my Island Mist Wildberry Schiraz kit that is done, I filled a small test bottle to the top so there was no oxygen in it, the PH was 3.6, I stirred the sample and did the drops but it was all I could handle to count drops, two of my friends watched for the color change and both agreed when it happened, so it is a two person job, my sulfite was 37.5, so the kits are pretty accurate. One of the lab testers makes his own wine from scratch and has never tested it, he just adds campden everytime he racks, going to have to bring him up to speed.

 

[AAASTINKIE]

medpretzel, a bad idea would be to go downstairs and get a scoup of sulfite out of one of the drums and take it home to put in my wine....now that is a bad idea...lol!! the test is the same add some powder and titrate till the color change.

 

[MedPretzel]

Well, it's great that it worked.





I'm happy about that.

 

[Hippie]

Those numbers look good Stinkie, although I would prefer ph 3.2 in a sweet, low abv wine. You might add a campden tablet before bottling to bring that free SO2 up a bit.

 

[Joseph1]

Scott,<?amespace prefix = o ns = "urnchemas-microsoft-comfficeffice" />

As a follow-up to your posts in this thread and your informative article on Sulfite in the May issue of “Pressing News”, I have a few questions on SO2 testing. Were you able to compare test results between the Acidometer test kit and your SO2 test kit? If the results are close, how do the test kits compare in ease of use?