Sulfites are in all wines. They are a by produce of fermentation. No one says you must add them. The problem is the wine will not last to long.
I know of no natural products that will do the same as sulfites.
If you drink wine then the winery adds alot more the us home winemakers do. So, you will have less sulfites than commercial wines
As home wine makers e add very small amounts compared to commercial wines but if you dont want to use them dont. Just dont expect them to last long as besides keeping your wine from oxidizing it prevents your wine from becoming a petri dish. Sulfites keep bacteria that ARE present in our wines at bay and thats why we try to practice keeping good sulfite levels.
Sulfites are the only preservative that's proven to have both an effective antioxidant and antimicrobial activity in wine. By the way, SO2 is no less "natural" than lemon juice. People in antiquity were aware that burning elemental sulfur in their amphorae would help preserve their wine... they just didn't know the reasons why it worked. It is a simple, "natural" chemical additive that has been around for ages. Also, the level of sulfites used in dried fruit and some other foodstuffs blows the amount used in winemaking out of the water, yet they seem to avoid controversy in those applications.
Also, just wanted to add that while the legal maximum limits for commercial wines are higher than what most home winemakers add, the actual SO2 levels in most commercial wines aren't much different than what we do at home. In fact, the move in the industry has been to reduce SO2 levels in recent years and with the increased use of inert gases throughout storage and bottling, most wineries have been able to keep quite low levels of both total and free SO2 since oxygen uptake can be better controlled. We tested some wines in my Wine Chemistry class recently and the free SO2 in both samples was around 30mg/l or ppm and the total was about 90 mg/l. You'd be hard pressed to keep them much lower than that at home, especially without the sterile filtration and microbiological analysis that commercial wineries use.
Chopin, if you are concerned about chemical additives, I urge you not to read the labels on a lot of the foods, especially processed, that you buy from the grocery store. Some of those things can't even be pronounced!! Look at a loaf of bread, Granny never added that stuff. I'd rather have a bottle of wine with some "chemicals" than I would have some of the other things added to our food we hope are safe.