Sulfur dioxide (SO2), or sulfites as they are best known in the wine world, is a chemical compound that occurs naturally at low levels during the process of wine fermentation. It is also added by many winemakers during the fermentation stage of winemaking to protect and preserve the wine’s character, flavor and color. It impedes the oxidation of the wine and prevents it from fermenting its way to vinegar.
Which Wines Have the Lowest Sulfite Levels?
Keeping in mind that all wines contain some naturally occuring sulfites, if you are looking for wines with the lowest level of sulfites organic wines are your best bet, because by label definition “Organic Wines” are produced from organically grown grapes without the addition of chemicals (including sulfur dioxide). Sweet white dessert wines contain the most sulfur dioxide with blush wines and semi-sweet white wines coming in at a close second for sulfur dioxide content. If you are searching for wines with the lowest levels of added sulfur dioxide you will need to swing to the opposite spectrum and go for dry red wines for the lowest sulfite content, followed by dry white wines as the middle ground choice.
The legal maximum sulfite level for U.S. wines is 350 ppm, with most wines averaging about 125 ppm. Naturally occurring levels of sulfur dioxide in a wine, without chemical additives, would weigh in at around 10-20 ppm.