First Time Using Hand Corker

[xanxer82]

A see a refractometer in my future...

 

[ArdenS]

One little twist on those numbers. Apparently, the pH for normal titration, using phenolphthalein, is 8.2. But if you're using the acidometer, which uses bromothymol blue, the change point is pH 7.0. (Jack Keller's 3/13/10 blog has a great write-up about it.)

 

[PeterZ]

Yes, the 8.2 pH is the TA test. In the SO2 iodide/iodate test the endpoint is when the indicator first goes black. In red wines it is hard to see, so people often add more titrant than they should have, resulting in a higher reading than the actual SO2 level. That's why you have to go slow and look for the slightest darkening.

 

[ArdenS]

Sorry, PeterZ; I didn't read carefully enough. You were talking about measuring SO2, not TA. My bad.

Arden