We lab test each wine to guarantee it is low in sulfites (less than 75 ppm).
Sulfites occur naturally in all wines during the fermentation process. According to US law, any wine with more than 10 ppm (parts per million) of sulfur - virtually every wine made - has to say "contains sulfites" on the label.
That said, our wines are about as close to sulfite-free as you can get while still having wines that are stable and have the ability to ship around the world. Sulfites can be naturally occurring up to about 30 ppm, and we respect winemakers that use minimal amounts of sulfites to protect their wines.
The 75 ppm limit that we set is low enough to prevent any kind of reaction in almost everyone (for reference, conventional wines usually have 150-300 ppm sulfites).