Oak Notes 4: The Oak Group

The Oak Group - Quercus and associates

Thought a little background on oak trees and why they are uniquely qualified to be in the wine and spirits business would help us appreciate their significance.

To botanists, oaks make up the genus Quercus which is part of the beech  or Fagaceae    family.   (Note:  Not trying to be pedantic but it is customary to italicizes Latin names in botany and biology).

Laymen are not so picky and include species that are not that closely botanically related such as “Silky oak” (Grevillia) and what the Australians refer to as “sheoaks” (Casuarina). Casuarina is called ironwood in Hawaii where it is considered an invasive species and has taken over hundreds, if not thousands of acres of pasture and former sugar cane land.

Beeches are big group (over 900 species) of shrubs and trees that are characterized by simple leaves,  flowers in the form of “catkins”,  male and female flowers on the same tree (monoecious) and nut like fruit.   

The beech family includes such familiar trees as (naturally)  beech, oaks, chestnuts and, if you’re from southern Oregon, chinquapins and tanoaks.  Unfamiliar species include a couple of tropical Asian trees.   Southern beeches (Nothofagus) of South America were formerly included but, as families too often do, have gone their separate ways (in the botanical sense.)

The wood of oaks and beeches is familiar to all of us - hard, heavy, strong, open grained and (with the exception of beech) has a pleasing figure - especially when quarter sawn.  This will become important to us a little later.

The oak group can be divided into two sub groups - old world oaks and new world oaks.   The old world oaks (Europe and Asia) are all white oaks.  The new world oaks developed an innovation - the red oak group.

Red oaks make pretty trees and lumber but they’re pretty worthless for wine barrels.  The reason is that their vessels - the tubes the tree uses to transport water and nutrients are very free flowing.  You can actually blow bubbles through them.  

White oak vessels, on the other hand, have occluded vessels and transport fluids very reluctantly, if at all.

Red oaks finish and absorb preservatives much better but white oak will hold wine and whiskey.

Stay tuned… more about oaks in our next installment.

As always, we welcome your feedback, suggestions, criticisms, clever repartee and even, pedantic corrections.