Wine Made with a Second Fermentation

After the fermentation process is concluded, the winemaker may choose to allow a wine to undergo a second fermentation. This process occurs as a result of the malic acid in the grape juice. When malic acid is allowed to break down into carbon dioxide and lactic acid, it is known as "malolactic fermentation." This second fermentation in the wine making process imparts additional flavor to the wine. A buttery flavor in some white wines is due to this process. Since malic acid is perceived as more sour than lactic acid, the process also reduces the perceived acidity of the wine.

The second fermentation is much more prevalent in red wines than in whites. When you sense the smell of apples in white wine, it denotes the presence of malic acid.

Wine Clarifying - Filtering and Fining

After the complete wine fermentation process, there may be a lot of stuff floating around in the wine. Some winemakers remove all these solid particles that are the natural result of the wine making process. There are various ways for the wine to undergo this process, called clarification. Wine Clarification is the process of removing such particles from newly fermented wines so as to leave the wines bright, clear, and visually acceptable. The process is necessary for more than cosmetic reasons. It also serves to remove many potential dangers and prepare the wine for bottling. Today, four clarification procedures are commonly practiced by wine makers: racking, fining, filtering or centrifuging. Wine makers may strain the wine through something a cheese-cloth type material. This is called filtering the wine. The filter acts the same as a coffee filter. The purpose of filtering is to remove yeast cells and other microbes, but it can also strip away positive properties of the wine. The most common way is called fining the wine and it is the preferred method for small boutique wine makers. The most common materials used for fining are gelatin or bentonite, which is a type of clay. The fining agents absorb or adsorb particles and are later removed along with the unwanted substances by racking or filtering. Another property of fining agents is they make larger particles out of smaller ones, making them easier to remove.

When and where to use heavy filtering and fining is highly controversial. Fully removing these substances prevents the wine from obtaining flavors from them and it affects the character of the wine. Wine makers that have made great wine are always concerned about fined and filtered wine. The implication is that such wines will have less flavor. For this reason some wines will state "UNFILTERED" on the bottle's label. There is a balance. Some winemakers use a machine that will remove the larger solids and leave those that are undetectable with the eyes. These are the solids that you will find in the bottom of finely aged wine bottles. As the aging process takes it course, the invisible particles accumulate and clump together. They then settle on the cork and on the bottom of the bottle.

Aging the Wine

Many wines are aged in oak wood barrels, but not all wines are aged substantially or even partiallybefore bottling. Also, not all aging vessels are made of oak. Quite a few wines are bottled just a few weeks or a few months after the harvest. In most instances these wines are stored in stainless-steel tanks, not in oak barrels. Stainless-steel containers allow wines to marry and come together as they shed their youthful aggressive flavors and harshness. They do not impart any flavors from the vessel. Long aging of wine is rarely performed in stainless-steel tanks.

If aged in wood barrels, the wine's flavor can come from the wood, or more correctly from the elements that make up the wood. French oak barrels are said to give the best flavor. These barrels must be replaced after several years of use. American oak is used by some producers. You can usually tell the difference between the American and French Oak. Some wine makers will buy the older, used French oak barrels and create wines that some feel are somewhat inferior, and also less expensive. Some wines may never see anything but stainless steel and the glass that they are bottled in. In any event, using oak barrels puts an "oakiness" characteristic in wine. Barrel aging can last for several months or for several years, depending on the wine and grape used. Generally, the smaller the container, the faster the aging process, and vice versa. Most boutique winemakers prefer to start out using large containers for new wine and then complete the aging process with small barrels, containing either 55 or 60 gallons. Several wineries prefer using an even larger oak barrel called a puncheon, which has a capacity of 135 to 150 gallons.

The Wine is Made

Ignoring any additional processing that might be used, winemakers can empty the barrels directly into bottles. However, during the barrel aging process the smaller barrels may develop differences. So winemakers tend to blend wines from different barrels in order to achieve a uniform result. Also, a winemaker may blend together different grape varieties to achieve desired characteristics. For example, blending a Merlot into a Cabernet Sauvignon can give a mellower tasting Cabernet wine.

In Bottles

Placing wine safely into a bottle is the final step of the wine making process. While it sounds fairly simple, it isn't. Bottling wines has shifted from primitive to clean and efficient. The primary goal is a sanitary environment to bottle the wine, with the objective of preventing tiny bacterium or yeast particles from entering the bottle. While most bottling is done with the use of machinery, some very small wineries still bottle by hand. Just prior to filling the bottle the winemaker may insert nitrogen, which will sit above the liquid preventing contamination by oxygen.

Wine producers often use different shaped bottles to denote different types of wine. Colored bottles help reduce the damage and oxidation of light. Wine bottle sizes can vary and are based on the Metric Volume Standards. The industry norms are as follows:

Applies to Wine Bottles other than Champagne

Split ..................................................... 187.5 ml
Half bottle ............................................. 375 ml     (a/k/a Fillette)
Bottle ................................................... 750 ml
Magnum ............................................... 1.5 liter    (2 bottles)
Marie-Jeanne ........................................ 2.25 liters (3 bottles) (Red Bordeaux)
Double Magnum .................................... 3 liters      (4 bottles)
Jeroboam .............................................. 4.5 liters  (6 bottles)
Imperial ................................................ 6 liters     (8 bottles)

Applies to Champagne Bottles

Split ...................................................... 200 ml
Half bottle ............................................. 375 ml
Pint ...................................................... 400 ml
Bottle .................................................... 800 ml
Magnum ................................................ 1.5 liter     (2 bottles)
Jeroboam ............................................... 3 liters      (4 bottles) (Burgundy)
Rehoboam ............................................. 4.5 liters    (6 bottles) (Burgundy)
Methuselah ............................................. 6 liters     (8 bottles) (Burgundy)
Salmanazar ............................................. 9 liters     (12 bottles)
Balthazar ................................................ 12 liters   (16 bottles)
Nebuchadnezzar ...................................... 15 liters    (20 bottles)

A case is generally 12 bottles or 24 half-bottles.

Corking the Bottle

The use of a cork to seal a bottle is totally unnecessary for wines that will not improve with age in a bottle, which is a majority of wines produced. A cork became associated with quality years back, when screw caps first appeared. Corks offer many advantages for protecting and aging wines. The best features of a cork are that it is compressible and adheres well to glass. Corks also give the wine maker an opportunity to be original with art and printing on the cork itself. While that is the up side to corks, there is also the down side. They have a tendency to leak (with about 3% having defects that affect the wine), to harbor bacteria, and to dry out when not kept moist. Lately many wineries are moving to artificially made corks. Made with rubber and other natural and synthetic materials, these corks have all the positive qualities of real corks but address the problems of inconsistency, oxidation and leakage. While they serve the purpose, they are somewhat balked at by those that prefer traditional corks on their wine bottles.

Champagne and sparkling wines have a different style of cork, intentionally made to withstand the higher pressure created by the effervescence. The mushroom shaped top is made in the shape of a knob, for convenient removal from the bottle. The fan like expanding insert of the cork is made to tightly seal the bubbly inside the bottle. Since the gas continually pushes on the cork to attempt an escape, the cork is held firmly in place by metal wire that latches on to the bottle.

For wines, a capsule is usually placed over the top of the bottle. Originally made from lead foil, fears of lead poisoning and changes in U.S. law have brought about the use of other metals, plastic, or even nothing at all over the cork. Champagne and sparkling wines still have the traditional cap, which also serves to hold the metal wire uniformly over the cork.

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