Sulfites in wine

[Wallace]

Foodie, I e-mailed your comments to Doc Peterson who shot back the following:

That's a pretty good explanation, Jim. The Only improvement would be to explain that ALL the SO2 added to wine goes into solution. The "Free" remains as simple, dissolved SO2, ready to react with oxygen and, in so doing, protect the wine flavor and other goodies from air. Some of the added SO2 reacts with a certain class of compounds in an unusual way. This can't
be stopped, it just finds the stuff it wants to bind with and does it. It ties up with the compounds 'loosely' -- tight enough to make the 'bound' SO2 unavailable to act against oxygen, but loose enough to be released again as SO2 under certain chemical conditions (the bound SO2 is not released in wine to become 'free' again but it can be released in other chemical situations).
For practical purposes the 'bound' portion of added SO2 is just wasted. It's a 'flavor tax' you have to pay to get the free you want in the wine.

Worse, it has a funky taste that many people don't like but can't quite put their finger on in judging. Personally, I think a high level of 'bound' SO2 in wine ruins the taste, and there's no way to recover that wine without waiting until next season, then adding the high SO2 wine in small amounts to
a new fermentation of the same grape variety. The new, vigorous fermentation
can sometimes reverse the binding and give you a clean wine again. Of course, you now have a blend of two vintages instead of one pure one, but, if you can keep the old stuff under 5% it will be legal to do that. Now you know one of the secrets of great winemakers who have to bring a small amount
of dead wine back to life. Dick P.