Wine 101 #1-Veraison

As we get lots of questions about grape growing and winemaking we thought from time to time we would would do an eduactional posting centered around what is going on in the winery or vineyard.

That said here is Class #1 in your very own Wine 101 class. Veraison is the topic of the day. We are going through veraison as we speak. What is veraison you ask? Very simply this is when the grapes begin to change color. Veraison is a french word/term for "changing color."

During verasion the grapes stop cellular growth and start the process of ripening (which is good as otherwise would not taste very good). Sugars begin to accumulate in the berries as the flow of water into the berry begins to slow relative to the amount of sugar. The rate at which sugar accumulates is directly related to the amount of canopy the vines have as photosynthesis creates the sugar.

In addition to sugar accumlation the the acids in the berries begin to drop off. There are two main types of acids in grapes, Malic acid and Tartaric acid. The malic acid degredates much quicker at this point and leaves tartaric acid as the perdominate acid in the grapes.

The grapes physically change color through the formation of anthocyanins and xanthophylls. Methoxypyrazines, the herbal green flavor compound, also begin to breakdown as well during veraison.

It is also interesting to note that what exactly triggers veraison is unknown. It is widely thought this process is triggered through hormonal changes or signals the plants send out but the exact reasons are still a mystery.

This picture is of Merlot in veraison last year. I will post some pictures of this year's veraison on Facebook.