Chapter 21

The Role of Oak in Winemaking

Types of Wine Oak Barrels

The source of oak is important to winemakers because of the genetic diversities of oak species that grow in different regions of the world. The different species can produce different flavors in oak aged wines. Generally speaking, there are three primary sources of oak for production of barrels for use in winemaking. These are America, France, and several nations across Central and Eastern Europe.

Oak Species for Cooperage

French Oak

French oak barrels are made from pedunculate oak (Quercus robur) or sessile oak (Quercus petraea) grown in the forests of France. There are five forests in France from which oak barrels intended for winemaking are sourced; Allier, Limousin, Nevers, Tronçais, and Vosges. Quercus petraea is found in the Tronçais, Nevers, Allier, and Vosges forests in France. Quercus robur is found in the Limousin and other southern French forests (Figure 21.1).

American Oak

American white oak (Quercus alba) is the oak used for American oak barrels. Most American oak used in barrel making is grown in the eastern half of the United States, from the Appalachian Mountains to Missouri, with some forests in Minnesota, Wisconsin, Oregon, and California.

Eastern European Oak

As the name implies, Eastern European oak grows in Eastern European countries such as Romania, Hungary, and Slovenia. Eastern European oak and French oak have very similar aromas, flavors, and mouthfeel.

Coarseness of Grain

Grain is defined as the average width between the annual growth rings of the tree. Trees grow outward, from the heart out to the bark, adding a layer every year just under the bark, in the cambium area. This incremental layer is called the annual growth ring. The grain is the sum of annual growth rings added each year in the life of a tree. Oak grain is often described as coarse meaning wider spaced growth rings and fine meaning closer spaced growth rings.

Flavor Profiles of French, American, and Eastern European Oak

The exposure of the wine to oak creates different flavor profiles depending on several factors including the species of oak, the capacity of the barrel, toast levels, and percentage of aging time in neutral versus new barrels. French, American, and Eastern European oak offer different flavor profiles when aging wine.

French Oak

All toast levels have a perceived aromatic sweetness and full mouthfeel

American Oak

American oak tends toward more intense flavors that can best be described as dark chocolate, dill, eucalyptus, mint, charcoal, tobacco, and wood. The one exception here is it’s often also quite sweet, with a punchy vanilla note often accompanied by coconut.

Eastern European Oak

Eastern European oak at medium toast displays a high perceived-vanillin content, with roasted coffee, bittersweet chocolate and black pepper characters.

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