A Deep Dive into the World of Winemaking – The Basics of Wine Grapes

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Whether you are a long-time wine lover or new to enjoying wine, you may be interested in a deeper dive into how wine is made. Our four-part series will cover the basics of wine grapes and how they are grown, how red wines are made, how white wines are made, and even how you can play around with making wine yourself at home.

First, let’s cover some grape basics.

There are just over 10,000 different grape varieties on earth. This includes table grapes for snacking, raisins, and our well-loved winemaking grapes. You may be surprised to hear that 33 of these are found in 50% of the vineyards around the world. If you’d like to learn more about specific grapes and the characteristics of wines made from each grape, look for the book Wine Grapes by Jancis Robinson. In this publication, she reviews 1,368 different grapes from super common to very obscure varieties.

The world’s most planted wine grape is Cabernet Sauvignon. This grape is an example of a variety that has red or purple skin and is used for making red wines. All grapes are green when they first form on the vine. During the growth of a vine and the ripening of the grapes, there is a process we refer to as veraison. This is the crucial stage when the grape berries begin to accumulate sugars, soften, increase in size, and change colors. Red wine grapes will start to turn a purple or red hue, and white wine grapes will become a lighter green or even yellowish color with more translucent skin. Temperature, sunlight, water, and hormonal changes in the grapevine are all factors that affect when veraison takes place. It is the final stage of grape maturation and indicates it is time for the winemakers to pay close attention to the grapes because harvest will be only a month or so away.

Every spring, grapevines that have been dormant during the winter months begin to wake up. Tiny buds begin forming on the vines, which we call “bud break.” This is an exciting time in the vineyard, but the buds are very delicate, and a late freeze, early heat spike, drought, heavy rain, hail, or high-velocity winds can damage the buds. Any damage to the buds at this point will directly impact how many clusters of grapes will grow on the vine this season. About six to twelve weeks after bud break, the buds unfurl into flowers. These clusters of tiny greenish-yellow flowers can pollinate themselves without the need for birds or bees like other flowers require. Ten to fourteen days after these flowers are in full bloom, the pollinated flowers form small green berries, which eventually grow into individual grapes. We call this phase “fruit set,” and it is our first true indication of how abundant this year’s harvest may be.

As you may imagine, weather plays a huge role in developing the grapes that make the wines we love. There is also a human interaction with the vines that can affect the quality of the final crop. Once the tiny grape berries appear, it is time to start thinning the robust leaf growth to encourage natural airflow through the canopy of leaves. We want dappled sunlight to penetrate through the canopy so the grapes can ripen evenly but not get too much light because, like people, grapes can get sunburned.

We begin to see veraison about six weeks after fruit set, often when “fruit thinning” or “cluster thinning” takes place. Clusters of grapes are cut off from the vine to reduce the number of grapes grown. This practice helps focus more of the vine’s energy on fewer clusters of grapes, making each individual grape healthier and more flavorful.

In Texas, harvest begins in mid-July, and depending on the location and the variety of grapes, the process extends into late October. Spring is the ideal time to visit a Texas winery. Learn next how red wine grapes make rich and delicious wines in Texas.