Barrels & Verticals: All About Oak

Jill Ruzicka - January 30, 2017

Our first annual Barrels & Verticals event is on February 25th and the Lake County Winery Association wants you to be prepared for the day with some fun facts about oak barrels.  The wineries that are participating in the event will be happy to answer questions about the barrels that they use, as well as their specific barrel aging processes, so don't be afraid to ask!  

Where they came from:

The history of using oak barrels for wine storage and aging is a difficult one to trace because of the nature of the material.  It decomposes quickly, and unlike its predecessor, the clay amphora, oak barrels aren’t commonly dug up during anthropological digs so their origins remain a mystery. 

However, it is highly agreed upon that the use of oak barrels for storage, and eventually wine aging, was brought to prominence during the Roman Empire, almost 2,000 years ago.  The Romans found the material to be more abundant, easier to manipulate, and easier to transport than amphora that was used before oak.  The tight grain of the wood also allowed for the optimal amount of oxygen into the wine, and by happy coincidence, it was found that oak also imparted a lot of flavor into the wines that it stored.  

How they help:

You’ve probably heard terms such as vanilla, spice, mocha, etc. to describe wines that are aged in oak, but it’s much more scientific than you might imagine.  First off, winemakers are not actually adding these ingredients to the wine.  These flavors are actually coming directly from the oak barrels.  There are chemical compounds that are exhibited after toasting the inside of the oak barrels that contribute to these flavors.  Winemakers can order barrels with various levels of toast (light, medium, heavy) and the oak can come from various regions of the world depending on what type of flavor profile they desire for their wines.  American and French barrels are most commonly used.  Here is a very simplified chart of the flavors that you might find in each type:

Wines that are being stored in oak barrels are not just resting and picking up these flavors, they also undergo a secondary fermentation while they are in the barrel. 

The secondary fermentation is called malolactic fermentation and it is essentially just converting the malic acids (the same ones you find in a green apple) to lactic acid (the same acid in milk).  Although this process can occur naturally, it is usually initiated when the winemaker inoculates desirable bacteria.  During this secondary fermentation, diacetyl is produced and this gives off a very recognizable buttered popcorn aroma.  The next time you purchase a box of buttered microwave popcorn, check the ingredients.  You should see diacetyl listed on the box!

How long is the wine aged in the barrel?

Not all wine is considered equal when it comes to time spent in the barrel.  It depends on the type of wine being produced, the region where it’s being made, and the stylistic preferences of the winemaker.  On average though, the aging time can look like this:

Many people often wonder how long a winery will use a barrel.  This differs from winery to winery as well, but after two to three uses, the barrels lose all of the flavors that they once imparted into the wine.  Eventually they will become “neutral” oak barrels, meaning that they don’t impart any flavor at all.  That doesn’t mean they’re useless though!  Wine can still be stored in neutral oak and is often preferred when winemakers are aiming for a certain style.  

In present day, wine barrels are used to a variety of craft projects, including the common planter box - check out Pinterest for all the barrel-to-craft ideas you’ll ever need!  It’s also important to note that wineries don’t have an unlimited supply of old barrels for your craft projects, but you local hardware stores might have a few.  

We hope that you'll be able to join us on February 25th with a new appreciation of the barrel aging process!


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