Sulphur in Wine

If you've ever looked at a wine bottle in the United States you've noticed a sinister little phrase "contains sulfites," usually printed in the fine print below an ABV statement. Let's have a conversation about them.

When grapes are harvested, they are placed in large containers in the vineyard to be taken to a winemaking facility to make our favorite fruit juice. While these piled grapes are treated with the utmost care, sometimes the weight of accumulated grapes can cause ruptures in berries spilling juice. Since there are naturally occurring yeasts in the vineyards which would immediately set to work on turning this spilt juice into weird wine, Sulphur Dioxide (SO²) is often used to purge the undesirable early fermentation.

In a red wine, that's your sulfites. Some SO² (which is naturally occurring in grapes to begin with) is added after harvest to prevent that early fermentation.

SO²'s miraculous abilities don't stop at killing yeasts. It also kills bacteria and keeps oxygen out of the wine. Which brings us to white wine.

After the fermentation process in a white wine, if left without SO², that wine would begin reactions to oxygen. If you've ever had an oloroso Sherry, you know what an oxidized white wine looks like (hint: it's brown). SO² keeps your white wine looking like white wine.

So should you be avoiding sulfites? If you are really serious about sulfites you should probably put down those delicious dried mango slices. Where a wine usually contains between 11.5 and 30 parts per million (PPM) of sulfites depending on its production, dried fruit can average 3500 PPM. A serving of French fries can average 1900 PPM.

Don't get me wrong, it is possible to have a negative effect from sulfites. However, if the person talking about cutting sulfites out is munching on trail-mix or ordered fries with their burger it is pretty likely that sulfites aren't their problem.