Did You Wine Know…: Sulfite Are Innocent! But Are They “Free”?

Last week, I posted some information about sulfites in wine, and their innocence with regard to being the source of wine headaches. Several W2WK readers commented and emailed about this topic and had some additional questions, particularly about wines labeled “sulfite free”. So this post is a follow-up to the original discussion to get to the heart of what it means to be a “sulfite free” wine.

Sulfite Recap

Before we get too far, here is a recap a few of the key points from the “Sulfites Are Innocent!” post to make sure all of us Winos are on the same page:

  1. Sulfites are a naturally occurring by-product of the fermentation process, and therefore, are present in all wines.
  2. Winemakers may add more sulfites to wine to help the preservation of the wine. This compound can keep the wine from oxidation and spoilage.
  3. A very small population of people are actually allergic to sulfites, so they are an unlikely cause of the headache one might have after drinking wine. Wine headaches are more likely due to difficulty metabolizing wine.
  4. Sulfite labeling laws are different in different countries. In the U.S., “CONTAINS SULFITES” is a requirement on a label for any wine containing more than 10 ppm of wine. In some other countries, the “contains sulfites” label is not required despite the presence of sulfites in the wine.

Parts Per Million (PPM)

For those of us who haven’t used terms like “ppm” since our high school chemistry class, I thought I’d refresh your memories on what that means. It is basically a measure of concentration – the amount of one material in a larger amount of another material. PPMs are expressed as concentrations rather than total amounts so scientists can easily compare a variety of different environmental situations. In this case, if you poured a bottle of wine that has a sulfite presence of 10 ppm into a million little cups, 10 of those cups would represent the total quantity of sulfites in that wine.  Most wine has about 150 ppm or less.

Ok… Now that we’re all refreshed with our basic sulfite Wine Know, let’s figure out what these other common sulfite-related declarations on wine labels mean.

“No Added Sulfites”

Some winemakers have started including “No Added Sulfites” on their wine labels. While the wine does contain the naturally occurring sulfites as a result of the fermentation process, this label indicates that the winemaker did not add any additional sulfites for the purpose of preservation. Again, adding sulfites helps prevent oxidation, which ultimately keeps the wine from spoiling.  Even if there are no added sulfites after the fermentation process, the wine label still must say “Contains Sulfites” if there are more than 10 ppm.

“Sulfite Free”

If all wine contains sulfites from the fermentation process, how can a wine claim to be sulfite free? According to the Alcohol and Tobacco Tax and Trade Bureau (TTB), which is the government organization that sets the regulations for wine labeling, wine must have “no detectable sulfur dioxide present” in order to be declared “sulfite free”.  From what I’ve read, this basically means that the presence of sulfites is so small, that it is not detectable based on the methods to measure the quantity. However, according to The Oxford Companion to Wine:

“There have been attempts to produce wines without any addition of sulfur dioxide. Such wines are particularly prone to oxidation and the off-flavours generated by wild yeast and bacteria.  They need careful handling and possibly even pasteurization. It would be impossible to produce an entirely sulfur-free wine since a small amount of sulfur dioxide is one of the by-products of the metabolic action of yeast during fermentation when the material being fermented contains sulfate salts. Since sulfate salts are natural components of such fermentable materials as dough and fruit juices, it is normal to encounter small amounts of sulfur dioxide in such fermented products as bread and wine.”

Interestingly, the alternative declaration on a wine label to “sulfite free” is “no detectable sulfites”. Although only a slight difference in meaning, a difference certainly exists. Either way, the amount is so small that as a wine consumer, when buying a sulfite-free wine, you may want to be more concerned about the wine spoiling due to the lack of preservatives in the bottle.

Intrastate Commerce & Sulfite Labeling

Another interesting tidbit on sulfite labeling is with regard to wine sold only in intrastate commerce. Wine that is produced and sold within a single state, is not required to declare sulfite content on the wine label. Since we often discuss Arizona wines here on W2WK, I’d like to point out that many Arizona wines are currently only sold in state since the wine industry is just getting off the ground here. So no declaration of sulfites on a local wine in a local wine shop doesn’t really mean anything!

Sulfite Testing Video

And finally, for you die-hard Wine Knows, here’s a little YouTube video from MidWest Supplies that shows how a Sulfur Dioxide Testing Kit works to measure the amount of sulfites in wine.

Phew! That was a lot of Wine Know for one week! Now we know that sulfites ARE innocent, but they aren’t exactly “free”!  I don’t know about you, but I’m ready to drink some well preserved wine and blame my future wine headache on the desire to have just one more glass!!

Sources of Wine Know for this post:

  • The Wine Bible
  • The Oxford Companion to Wine
  • Alcohol and Tobacco Tax and Trade Bureau