Very interesting comments here. I actually DO have a sulfite sensitivity that seemed to develop the same time I developed very mild asthma. I don't seem to have any issues with products that naturally contain sulfites but if I eat grapes treated with sulfite or wine that is listed as containing sulfites (meaning over 10 ppm) I get itchy red blotches on my chest and arms that takes several days to go away. So believe it or not some people really do have sulfite issues. As to your question I have found that the grocery store bought red wines in the box (my choice is cabernet sauvignon) don't bother me at all. Most are not labeled as containing sulfites so they must just contain natural amounts or the amount added is under the 10 ppm limit for listing. Maybe its because of how they are sealed without air in the plastic bladder of the box as compared to being in a bottle with air. I know this post is extremely old but maybe it will help someone searching for information.