The only time I can recall sending wine back was when we were eating with about 6 or 8 others at a generally ordinarily place. A bottle of red and a bottle of white were ordered. Non descript stuff. The white was opened and poured at the other end of the table, about 5 feet from me. It came out and was brownish, like it was totally vinegar. Before anyone tasted it, just from the look of it, I knew it was bad, and so I told the waitress to get rid of it.