Recently I had a few problems with sulfites in my wine. It is not what you think. In fact, it is probably the opposite of what you think. I forgot to add sulfites to my wine. I'll get into that in a minute. But first let's talk about more commonly known problems with sulfites - real and perceived.
Sulfites are naturally occurring compounds found in wine and other food sources such as peanuts, eggs, and tea. Because sulfites are also antioxidants, they are often added as preservatives to slow down browning or discoloration of food.
In the 1970s as salad bars gained popularity in the United States, there was a dramatic uptick in the use of sulfites to keep the fruits and vegetables "fresh." With that came a rise in the cases of severe sulfite reactions. Sulfite sensitivity manifests in asthmatic symptoms such as wheezing and in rare cases anaphylactic reactions. Some people develop hives, swelling, or stomach pain.
In 1986, the Food and Drug Administration (FDA) banned the use of sulfites in salad bars as a response to the increase in cases of sulfite allergy and sensitivity. It is estimated that about 1% of the population is sensitive to sulfites, and those with asthma are more susceptible.
Contrary to popular belief, headache is not a typical reaction to sulfites. But because many people suffer headaches from wine consumption, sulfites have become the easy target. In reality, wine-induced headaches are more likely due to dehydration from alcohol consumption or from the histamines and other compounds in wine.
That said, the market wastes no time in capitalizing on the perceived problem of sulfites by offering a multitude of solutions, from sulfite-free wines to sulfite-removing wands, filters, and drops. While these may be effective in removing sulfites, one wonders if they eliminate wine-induced headaches or hangover since there is no scientific evidence that sulfites are the cause. There is however no accounting for the placebo effect.
Too Little Sulfites
The addition of sulfites during winemaking is necessary for the production of high-quality wine. Winemakers often pitch potassium metabisulfites into the wine post-fermentation to protect it from spoilage. When sulfites come into contact with the water in the wine, sulfur dioxide (SO2) is released. A portion of the SO2 will immediately bind with certain chemicals in the wine while the remainder will be in a free state (FSO2) to take on harmful microorganisms and to slow down premature aging of the wine.
My first problem for my 2020 vintage is that I forgot my post-fermentation sulfites. While the science behind how much and when to add sulfites is complex and entails conducting multiple tests, a good rule of thumb for hobby winemakers is to pitch a certain amount every month to ensure adequate protection of the wine. And I did none of that this past vintage.
It was not till I ran a pre-bottling panel on my wine four months after fermentation that I found out that there were only 2 parts per million (ppm) of FSO2 in my wine. That is winemaker's talk for virtually zero protection for my wine from spoilage.
Using the pandemic analogy, it is like going to a store without the protection of a mask or vaccination and hoping not to catch COVID. Thankfully, the wine was still tasting fine.
Too Much Sulfites
In my moment of panic, I googled the first website that gave me the target FSO2 level based on my wine pH. I did a quick calculation and pitched the sulfites as quickly as I could. Then I found a couple more websites that suggested target FSO2 levels that were significantly lower than the first website. One of the later websites had a target FSO2 level that was half of what I had pitched.
Great! Now a giant sulfite-removing magic wand doesn't sound so bad.
The truth is that it is hard to determine the right level of FSO2. Each wine's chemical makeup presents numerous variables that may bind with the sulfites, making it hard to determine how much FSO2 is left without running yet another test. Too much sulfites will inhibit the wine's ability to develop in complexity and give the wine a chemically metallic taste. Too little sulfites will increase the chance of spoilage. The winemaker treads lightly between the two.
Using the pandemic analogy again, it is like wearing five masks to the store which may protect you from COVID, but you may not be able to breathe.
Since I don't have a giant magic sulfite-removing wand, I decided my best recourse is to rack the wine despite mixed reviews with this approach. Put simply, wine racking is siphoning wine from one vessel to another, a process that introduces oxygen that will hopefully bind with excess sulfites.
My Verdict: This is my fifth vintage. With every vintage, you learn something new that will help you improve your winemaking skills for the next vintage. There is no magic wand in that. I will let you know in 6 to 12 months how the vintage tastes.