There are many myths and misconceptions surrounding wine and the process of wine making. Some of this comes from the process of making wine, which is dense in technical language and based in science just as much as art or agriculture.
One common misconception centers on tannins and sulfites in wine, and what the difference between them is.
One obvious difference is that wine bottles in the US are legally required to indicate that they contain sulfites but not tannins.
Both tannins and sulfites are natural and vital to the wine making process, but in their own unique ways. Tannins help create the balance and body of a wine while sulfites help to preserve fermented wine.
Where Tannins and Sulfites Come From?
Contrary to popular belief, both tannins and sulfites are completely natural to the wine making process, and in a sense cannot be removed from the process. This is because both come naturally occur in grapes and are increased during the processes of wine making.
Starting with tannins, they are the result of polyphenol compounds found in the ingredients for making wine. Specifically, the skin, seeds, and stems of grapes which are often left in fermenting juice. This is why red wines are more tannic than white. White grapes most commonly are pressed off their skins at harvest. Red wine without contact with grape skins, seeds, and stems would still be white!
Polyphenols are natural compounds made of oxygen and hydrogen molecules strung together in long chemical chains. They naturally form in the skin, seeds, and stems of grapes and are released into solution as they ferment along in the must.
Sulfites are a different case altogether, even though they are still natural to the wine making process. The term “sulfites” is shorthand for sulfur dioxide, a naturally occuring compound of sulfur and oxygen.
In wine making terms sulfites come from metabolizing yeast during the fermentation process. In other words, as the yeast added to wine juice is used up it creates sulfites. Some modern vineyards also add extra sulfites directly to the mixture for reasons that will be discussed in the next section.
So, while tannins and sulfites are a natural part of the grapes used in wine making, sulfites are also produced during the fermenting process. This is the difference between tannins and sulfites in regards to where they come from.
What do Tannins and Sulfites do in Wine?
As they are different chemicals with different sources, tannins and sulfites have profoundly different effects on the qualities of wine. These effects occur at different stages, with tannins being important for the quality of the final product while sulfites are most important just after fermenting.
Tannins are primarily involved in balancing the taste and texture of wine. This is primarily done by providing a bitter or acidic taste to the wine to help create a more complex flavor. Wines short on tannin are much more simplistic and cloying in their flavor.
Tannins also help dictate the texture of wine in the mouth through a few key characteristics. Tannins create a sense of weight and over time as the tannin’s break down they create a smoothness in wine that helps give it a fuller, more noticeable body. This is one of the reason oak barrels are used in winemaking. Oak imparts and absorbs tannin. The tannin imparted by oak is known to be smoother and creamier where the tannin imparted by stem and seeds can be rather harsh. A quick test of how much tannin is in a wine is if after swallowing your mouth dry’s out.
In contrast, sulfites have a simple and straightforward effect on wine production, they help preserve wine. Sulfites are a source of antioxidants and a natural antibacterial that helps keep wine fresh during storage. Without sulfites wine might only last a few months after being aged.
As another point of comparison, sulfites have little effect on the flavor and body of wine, aside from preserving it that is. Unless a bottle of wine has an overwhelming amount of sulfite in it, the chemical will have little to no impact on how a wine tastes or feels. The legal limit for sulfur additions in the Europe is 150 mg/L for red wines and 200 mg/L for white versus in the US which is 350 mg/Litre for all wine. This has lead to much of the misconceptions regarding sulfur in European wines vs. American wines. An average for a well made red wine in the US would be 50 mg/L well under the European limit. White wines often require more sulfite to preserve the clear bright color and not suffer from browning.
Thus, tannins are an integral part of a wine’s taste and texture, while sulfites are primarily useful in preserving wine for storage. That is another key difference between the two chemicals, tannins are felt in the wine while sulfites should not be.
Are Tannins and Sulfites Safe?
This is a common misconception about tannins and sulfites, and is one of the few areas where the two are similar, but not the same. Both compounds are natural and can actually have some benefits.
In this section it is important to remember that other edible products like tea and fruit have higher levels of tannins and sulfites than wine. If you enjoy tea, chocolate, or raisins these foods contain just as much if not more tannins and sulfites than wine. In several studies dried apricots were shown to have sulfite levels up to 3 times higher than raisins and apples.
Tannins, for example, are completely safe and natural in wine since they are part of the grapes used to make wine. In fact tannins have antioxidant properties which have health benefits. This means tannins actually increase the benefits of wine rather than making them dangerous.
Sulfites are also naturally occuring and safe to consume and play a key role in keeping wine fresh, but beyond that they have no apparent, immediate health benefits. This is in contrast to the antioxidants that come from tannins in wine, as sulfites do not give any benefits to wine other than longevity.
There is one exception to keep in mind when talking about tannins and sulfites in wine, that being if someone has an allergy. If a person is allergic to tannins and sulfites they might feel headaches or migraines. This only happens if the person is already averse to tannins and sulfites. A good way to know if a negative reaction is due to tannin or sulfites is to think about your diet. If you can eat dried fruits or drink white wine it’s not sulfites. If you can drink tea, coffee or chocolate it’s not tannins.
So, while both tannins and sulfites are safe in wine, unless someone is allergic to them, tannins actually have health benefits while sulfites help keep wine fresh enough to drink.
One common question among wine enthusiasts is: what is the difference between tannins and sulfites in wine? Tannins are a natural compound found in grapes which add to the flavor, body, health benefits, and overall quality of wine. Sulfites, on the other hand, are the result of natural ingredients in fermentation that helps to preserve wine for storage.
These are the differences between tannins and sulfites in wine, tannins create flavor while sulfites preserve quality.