As discussed in the first two parts of this series, the wine making process begins with harvesting the grapes and then proceeds into fermentation. But, once the natural sugars in the grapes are converted to alcohol, the process isn’t over. The aging process is the third and final stage of wine making. And, it takes place in the winery and in the bottle.
Following fermentation, wines go into barrels, bottles, or storage tanks. Some wines will age for a few years before being released while others may age just a few weeks.
During this time, wines may undergo several processes. Sediment in the wine such as dead yeast cells, grape seeds, stems, pulp and tartrates (harmless tartaric acid crystals) may remain in a barrel or tank during and after fermentation. Immediately following fermentation, wine may be "racked" to remove this sediment or “lees.” Or, the wine may be aged for an extended period on the fine lees in what's called "sur lie" aging. Fine lees can enhance an aging wine with added richness, flavor and aroma complexity, and can also bind with excess tannins.
Fining is another technique used for clarifying wine using agents such as bentonite (powdered clay), isinglass (fish bladder), casein (milk protein), gelatin or egg whites, which combine with sediment particles and cause them to settle to the bottom, where they can be easily removed.
White wines are generally aged in vessels that preserve the grapes natural fruit flavors as much as possible. This is done by using stainless steel tanks, concrete tanks or neutral barrels (barrels than have been used for more than three vintages) which do not add oak flavors. But, Chardonnay is sometimes aged in new oak (up to three years old) to impart flavor and give it that “buttery” flavor.
Most red wines (and some white wines – especially Chardonnay) go through Malolactic conversion where sour acids (malic acid) are converted to less harsh, smoother acids (lactic acid).
Red wines are then typically aged in oak barrels. These may be new oak barrels (never before used) to impart bold oak flavors, a combination of new and neutral oak to add moderate oak flavors, or completely in neutral oak to impart no oak flavor.
Once the wines are through the aging process at the winery, the wine is bottled. Sometimes the wines are immediately sent to market while other wineries may choose to let their wines (usually reds) spend another year or two in the bottle before going to market.
So, wine making may seem easy, but to make a really good wine is quite difficult and involves multiple time-consuming processes.
The three parts of this series are meant as an overview of the winemaking process. Future blogs will deal with specifics in greater detail.
So, here to the wine makers who make it all possible. Cheers!