Aging Wine and Deciding when to bottle

Ok, Vino fans. Time to take a break from Political discussions.

Aging wine in Oak barrels. Barrels have an effective life of about 5 years where they impart some Oak flavoring. After this time period the Barrels become "neutral". Still useful for aging, and Oak character is not added. There are other mechanisms to add Oak characteristics. Some vintners when fermenting grapes in stainless steel vats, will add Oak staves. The heat of the fermentation extracts out the Oak quickly. Nuetral barrel can be reconditioned, ie, take the end cap off, and then have the interior scraped, sanded and refired. This is labor intensive, and adds maybe two more years of effective Oak flavor addition.

Another options is to add Oak Beans (small round or square pieces of Oak, fired and toasted) to nuetral Oak barrels, or it doing long term aging in stainless steel, or glass, Oak beans/chips can be added.

Deciding when to bottle wine is a matter of taste, and chemistry. Chemistry is the most important piece because it ensures future stability of the wine once its in the bottle. A by product of fermentation is the formation of Malic Acid. Malic acid will naturally breakdown, or convert over time into other compounds. This can take a long time, up to 18 months in an Oak Barrel. A mechanism to accelerate this activity is adding a Malolactic bacterial culture to the wine toward the end of fermentation. Doing so converts the Malic acid much more quickly, in a few weeks. Doing so "softens" the wine. A chardonnay that has Malolactic culture added will produce a buttery element, if "Malo" is not added, then not all of the Malic Acid is converted, and the wine ends up with a sharper edge.

Aside from the chemistry angle it's a matter of taste. It's hard to describe how much a wine changes taste in a barrel over time. All I can tell you is that every month, the wine changes in flavor noticably. Even if I have a brand new barrel, I will still leave the wine on Oak for 9 months before bottling. I have gone as long as two years. It just depends upon the wine.

More and more though, my decision is being driven by storage capacity. Each Fall I harvest the grapes in September or early October. Fermentation, pressing, racking, etc, takes about 6 weeks. Once the wine is ready to be moved to Oak barrels I have to have available space in the barrels to move the new wine in. So, now I typically bottle the prior years harvest, the week before I move the new wine in. This allows me time to clean out the old barrel, treat it properly, and get it ready for the next batch. Cleaning is important because tartrates can build up on the interior of the barrel, creating a film that inhibits the barrel from imparting it's precious Oak flavoring. The cleaning exercise is simple. Once the wine is pumped out for bottling, the barrel is then repeatedly rinsed with water with a high pressure nozzle, especially designed to work inside a barrel. After each rinsing the barrel is drained. In between you just peek inside with a flashlight to look around. The interior of the barrel can be scraped with a barrel brush as well. Once this is done, then a solution of Citric Acid and water is poured into the barrel and rolled around. This also helps clean the interior and treat the wood. Lastly, a solution of water and Sulfur Dioxide is added, and rolled around. This will kill any airborn bacteria, and especially it is important to kill any airborne bacteria that produced vinegar. If this bacteria gets into the interior of a barrel the barrel is forever ruined.

All of the 2005 harvest was moved into Oak in late October, and early November. The first bottling will occur in early July. Which will mean that wine (my Estate Cabernet) will have had about 8 - 9 months of Oak contact). My taste buds say it's ready. It still has a strong fruit component which I don't want to lose.