They're "sulphites" in Britain and "sulfites" in America, depending on whether you say "sulfur" or "sulphur." Tomato, tom-mah-toh --- however you say it, sulfite has a nasty little reputation in wine making and is mired in controversy.
Sulfites are present in all wines and are formed as a natural product of the fermentation process. Sometimes sulfur dioxide gets added to wine to help preserve it. The level of added sulfites varies. Some wines with low sulfite content have been marketed as more "organic." It is largely believed that high sulfite wines can aggravate a person's asthma. So, other than closing people's breathing passages, what are the pluses and minuses of sulfite content?
Wolfgang M. Weber attempts to straighten out this sulfurated brouhaha in the San Francisco Chronicle.
Under the headline, "Reconsidering Sulfites: Progressive Vintners Weigh the Pros and Cons of the Controversial Winemaking Tool," Weber writes:
"On almost every wine label, a challenging subject is concealed behind an opaque, almost nonchalant warning: 'contains sulfites.'
"The term encompasses sulfur dioxide as well as many derivative forms of sulfur. Sulfites are present in all wines both as an additive and as a natural by-product of fermentation, and many countries require that their presence be indicated on the label.
"Long viewed as a necessary, if unromantic, tool by winemakers, and either ignored or completely misunderstood by consumers, the role of sulfur in wine has become a hot topic. From health issues to sulfur as a winemaking tool at a time when there's a push within the industry for wines made with minimal intervention, sulfur dioxide is in the spotlight like never before.
"Sulfur dioxide has been used in the production of wine for centuries - primarily as a buffer to keep wine from reacting with too much oxygen, but also to inhibit microbial spoilage (from bacteria or rogue yeasts) that could lead to off flavors and aromas, and as a winemaking technique to partly control fermentation."
You can read more about Weber's defense of sulfites here.