In this article, we are going to talk about Anthocyanins. Their purpose in nature and their effects on wine.

Anthocyanins are phenolic compounds found in many different plants around the world. They have red, purple, blue, and black colors and occur primarily in fruits, flowers, and leaves. The most prominent fruits with a high anthocyanin content are blueberries, black crowberries, red cabbages, black beans, purple corn, and obviously grapes.

In grape berries, the coloring developed to attract animals, just like us, to help them spread their seeds and thus their genes. So from an evolutionary perspective, white grape varieties don't really make sense… Hence they almost never appear in nature, because the lack of color is caused by two separate mutations. Researchers suggest that all white grape varieties can be traced back to one common ancestor that was lucky to be discovered by a human.

Different varieties have different concentrations of anthocyanin but almost all of them contain their pigments in the first few cell layers of their skin. A few exceptions are the so-called teinturier varieties, like Alicante Bouschet which has anthocyanins even in its pulp.

But all the major grape varieties that we use for red winemaking belong to the first category. So to transfer these color compounds from the grapes to the wine, we have to use a process called maceration. I am working on a video explaining this whole process, so don't forget to subscribe so you won't miss it.

The main idea behind it is that the grape skins are in contact with the grape juice for a longer period, to extract the color and other beneficial compounds.

Without the maceration process, it is possible to make white wine from red grape varieties. For example, in Champaign, the Blanc du Noir (which means White from Black), is a white Champagne made only from black grapes.

But why do different red wines have different color variations if all of them contain the same anthocyanin? Well, Anthocyanin is kind of like a chameleon. It changes color all the time based on the environment it is in. When the wine has a lower pH level, meaning higher acidity, it gets a bright red color. On the other hand, if the wine has a higher pH level, it is going to get a more bluish hue, which causes a purple-like wine color.

Also, a brownish color might appear when red wines are aged for longer periods, and the anthocyanins react with other compounds in the wine, like tannins giving it a so-called “brick red” hue, commonly known as the aged wine color. Through this process, some of the compounds exceed their solubility and become sediments. This is one of the reasons for decanting older wines.

Unlike some people on the internet, besides their visual aspect, Anthocyanins also have other purposes in life. They increase the antioxidant capacity, which determines the aging potential of a wine. Combined with tannins, they affect the mouth feel and astringency of the wine.

Anthocyanins also have beneficial health effects on us. They are used in different medications and skin care products. In the last years, there have been studies that showed some extreme effects, like cancer prevention, and heart disease treatment but these claims need more research. And also in many cases, it has been shown that to get any of these health benefits you would have to consume impossible amounts of anthocyanin.

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