Vintner Views – August 2007

Barrel Anatomy 101

   An oak barrel is a classic symbol in the world of wine.  While some of the best wines in the world are aged in oak, it’s certainly not an absolute requirement for a quality wine.  The barrel also happens to be the product of a very old craft, called cooperage, with a very interesting history and heritage.  What are the different parts of a barrel, and how are they put together?  Why do wineries use barrels, and why are they oak?  Can any oak be used?  We’ll answer these questions and more in this and subsequent articles.

   First, let’s talk about the anatomy of a barrel.  A barrel consists of two heads, making up the front and the back, and the belly, or the bilge, which are the curved sides of the barrel.  The heads are shaped like disks.  They are made of 5-8 oak boards, maybe ¾” thick, and are sometimes dowelled to keep them together.  No glue is used in making a barrel since adhesives and wine are mutually incompatible.  So all the pieces are shaped and formed to fit together perfectly.

   The belly of the barrel is made of “staves”, which are basically boards about ¾” thick, from three to five inches wide, and running the full length of the barrel.  The staves are bent using various combinations of heat, steam and mechanically applied pressure to create the curved belly of the barrel.  Keeping the staves together tightly enough to prevent leaking are the steel hoops which are hammered and nailed with special nails to keep them in place.

   There is only one way into and out of the barrel once it’s assembled.  It is called the bunghole.  Normally, when the barrel is full of wine, the bunghole is the highest point of the barrel, and the bung, usually a silicone plug of some sort, is firmly inserted to prevent ingoing and outgoing traffic.  When wine goes into or out of the barrel, a special tool is required.  It’s usually a stainless tube assembly that reaches all the way to the bottom.  This tool prevents excessive aeration of the wine when filling the barrel, and unnecessary loss of wine when emptying the barrel.

   There are a few other terms in the cooperage biz which may be of interest.  The “chime” of the barrel is that portion of the stave that sticks out past the heads by a couple of inches.  When working in the barrel stacks, the chimes are extremely helpful as the cellar rats climb up and down to fill, empty, take samples or whatever the job might require.  The chime also is a good handle when moving the barrels around for cleaning and stacking.

   When coopers install the heads, they use a water and flour mixture they call dough, of all things, to help seal the joint between the head and the chime.  This joint is called the croze.  Coopers and wineries use river reed, another natural and food-grade material, to seal imperfect surfaces and further prevent leakage.

   As you can see, cooperage is a fully mature industry on its own, and one that few people get to see firsthand.  Coopers build barrels for wine or whiskey in only a few parts of the country.  California has a number of cooperages, as does Missouri, but for different reasons.  Missouri coopers locate there because they grow White Oak, the tree of choice, in that part of the country.  California cooperages on the other hand are located for their proximity to the large number of wineries.  Who knows, maybe we’ll see a cooperage on the Western Slope in the not too distant future.

   Next month we’ll talk about the 2007 Colorado Mountain Winefest that takes place on the third weekend of September.  In October we’ll come back to the discussion of the mighty oak barrel and its role in winemaking.

This article appeared in the August 9, 2007 edition of the Grand Junction Free Press.

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