Last time we discussed how all the fruit flavors get into wine. We discussed that wines don't actually contain fruit other than grapes, but the grapes, the soil they are grown in, the fermentation process, and the aging process can impart other fruit flavors.

Another way that flavors can be added to wine is through oak aging.  Oak barrels add additional quality, character and smoothness to wines and can create flavors of vanilla, butterscotch, coconut, toffee, caramel, butter, mocha, coffee and smokiness. 

The vanilla flavor in wines come directly from compounds in the oak itself. But often the interiors of wine barrels are 'toasted' over an open flame. This process affects the degree of flavor added to the wine. Barrels may be toasted light, medium or heavy. Light toasting of the barrels results in wines having flavors of butterscotch, toffee, caramel, coconut, and butter. Wine flavors of mocha, coffee and smokiness are brought out of the oak by heavier toasting of the barrels. 

Oak barrel aging is used for most red and white wines of the world. But, it comes with a cost.  French oak, which is considered the 'gold standard' of oak barrels, can cost $800 to $4000 dollars each.  And an oak barrel is only able to add flavors to wines through two to three uses. After that, oak barrels become 'neutral' and are simply used as vessels for storing wines with little or no flavor being added. Oak barrels from the U.S. cost $350 - $500 each and, like French oak, only impart flavor during their first two to three uses.

One oak tree can only produce enough wood for approximately two barrels, or 50 cases of wine. And, when aging wine in a barrel, the wine only comes in contact with the oak on the inside of the barrel. So, winemakers seek alternative ways of getting oak flavors in their wines. Options include adding oak chips, oak cubes or oak staves directly into the wine as it ages in stainless steel tanks. This allows the entire surface area of the oak to be in contact the wine and is much less costly than barrels.

So start paying attention to these wonderful flavors in your wines. And remember, all the flavors are coming from grapes, yeast and sometimes oak.  Cheers!