RED WINE PROCESS & OAK

This chart shows a simplified way of making red wine 

The key to red wine is the successful extraction on the tannin and color from the skins of the black/red grapes. This is accomplished by mixing the skins around during the fermentation process.
The grapes must be harvested when tannins are ripe but not affected by noble rot( used in the making of some sweet wines) 

Pre-fermentation extraction 

Some wine makers prefer to leave the grapes to macerate(soften or break down by using liquid) for a time to extract greater color and flavor aromas. Or heat the grapes to encourage the grapes to release color this can reduce the fresh fruit aromas.

Extraction during fermentation 

The presence of skins makes alcohol fermentation in oak barrels impractical because it would be difficult to maintain contact between the skin and the juice. Red wine fermentation normally reaches between 30°-32°c higher temp.s improve extraction of color and tannins. But fermentation will stop(as described in Wine making:The beginning) if temp. gets above 35°c.

If left to itself the wine will soon have a thick mass of pulp and skins on the surface, called the cap, and will not extract color or flavor.

There are several extraction methods

• Pumping over: Drawing off the wine from the bottom of the tank and pumping it over the top. This is used in the production of most red wines and is usually done several times. The oxygen is useful for helping the yeast populations grow.

• Punching down: Punching down the cap by hand using paddles. This was dangerous because the workers could have been over come by carbon dioxide.  
• Rack and Return: Draining all the juice, leaving the cap behind, racking the cap and pumping the juice back over. 
• Rotary fermenters: a modern device that ferments the wine is rotating horizontal tanks 

Post-fermentation extractions 

The fermentation time will vary but is typically from one to tree weeks for red wines. The length of the time the juice is in contact with the skin depends on the style of wine being made. Example: to produce a low tannin fruity wine the skins will be drawn off once fermentation is finished. Or to create a wine that will age for a long time the skin will stay in contact for several weeks after fermentation. French and Italian wines use this for high-quality wines that are intended to age. 
 Once the juice is drained off the remaining mass is pressed to create a press wine. This has deep color and high in tannins. This is used to balance color and tannins in the blending process.


OAK

Is primarily used to add tannins which add to the structure, color and texture complexity in red wines.
The wines also extract aromas such as vanilla toast and smokiness from the oak. There are two different kinds of oak vessels
French Oak:This is more expensive and tends to give vanilla and toast flavors.
American Oak: Generally more aromatic flavors such as Sweet vanilla and coconut.
New heavily charred barrels give the most flavor. Small oak barrels have a far greater impact on the final flavor of the wines than the larger barrels. The standard small size is 225 Liters and is generally used for aging red wines. This produces 300 bottles. Large oak barrels give very little oak flavor and can be as large as 200 Hectoliters

Oak flavors can also be added to the wine by using Oak chips or Oak staves. Both methods ensure oak and wine come in contact and come at a much lower cost than using barrels.