While doing research on suflites in wine, I learned a couple of things:

1. Sulfur dioxide aka sulfites are added into wine as a preservative.
2. White wine has more sulfites than red wine.
3. People with asthma are more likely to have a reaction to sulfites.
4. Red wine has less sulfites because it has tannins added which is also a preservative.

The 4th point is what I wanted to expand on a little more in this piece because the art of wine making is becoming a more increasingly complicated topic than I first anticipated. It makes sense that preservatives need to be added (or naturally exist) in wine to slow down the fermenting process but I love diving more into what exactly these preservatives are.

What are tannins?

Tannins are naturally occurring compounds that exist inside grape skins, seeds and stems. The scientific word for these compounds is polyphenols. Polyphenols release from the skins, seeds and stems when they soak in the grape juice just after the grapes have been pressed and are what give certain wines, such as Cabernet Sauvignon, their characteristic dryness or astringency. You experience the effect of tannins any time you drink a wine that creates a drying sensation in your mouth. Depending on how dry your mouth feels, you can determine whether a wine is high or low in tannins. We say a wine that is high in tannins is tannic.

Tannin tastes dry and astringent and you can feel it specifically on the middle of your tongue and the front part of your mouth. Unsweetened black tea is a great example of nearly pure tannin dissolved in water.

Source: Wine Folly

From my research I gathered that tannins in wine originate from two places. The first is the ingredients like the grape skin, pip, and stem. The second is where the wine is stored to mature. Wine is often stored in oak barrels which not only enhances the colour and smell but now we’ve learned that it also affects the taste, the dryness in particular.

The typical wines that are high in tannins are the bordeaux, cabernet sauvignon, shiraz and syrah. The wines lower in tannins are the more sweeter, pinot noirs and malbecs.

Want to avoid tannins?

Essentially, there is only one way to avoid tannins in wine. Avoid the more “bitter” and “dry” red wines. Opt for more rosé or white wine.