Making Wines
Making White Wine
Crushing. After picking, white grapes are crushed, drained and/or pressed to separate the juice from the skins before fermentation.
Pressing. The crushed grapes go into a wine press to release the remaining juice.
Fermentation. Yeast are added to the grape juice to consume the grape sugars and make alcohol. This can take place in stainless steel tanks or oak barrels. Alcoholic fermentation takes about 14 days to ferment a white wine. The winemaker controls the sweetness level. To get a slightly sweet or “off dry” wine, he simply stop the yeast by super chilling it. Malolactic fermentation is an acid conversion carried out by a little bacteria that eats malic acid found in the wine and poops out lactic acid. This kind of fermentation is optional but creaminess you get in some wines is of this particular winemaking process.
Maturation. Once fermentation has finished, the wines can be stored in stainless steel tanks or oak barrels.
Bottling. It’s very important to do this step with as little exposure to oxygen as possible.
Making Red Wine
Crushing. After picking, black grapes are crushed and put into the fermentation vessel. Depends of grape varieties the winemaker decides whether or not to remove the stems or to ferment grape bunches as whole clusters. Leaving stems in the fermentation adds astringency but also reduces sourness. As an example, Pinot Noir often ferments with whole clusters, unlike Cabernet Sauvignon.
Fermentation. Yeast are added, and fermentation starts. The fermenting juice gets frequently stirred to submerge the skins. One way to do this is to pump wine over the top. Another one is to punch down floating grape skins with a special tool. The first method rigorously extracts lots of flavor from the grape skins and makes for rich reds. The second one downs extract flavors more delicately and thus they tend to produce more subtle red wines. Most wines take 5–21 days to ferment sugar into alcohol. As the red wine settles in tanks or barrels, a little microbe feasts on the wine acids and converts sharp-tasting malic acid into creamier, chocolatey lactic acid.
Draining. Red wines. Once the fermentation is finished, the newly made red wine is drained off the skins.
Draining. Rosé wines. After only a few hours, the juice is drained from the skins. At this point it is only pink in color. It finishes fermentation without the skin.
Pressing. Red wines. Vintners put the remaining skins into a wine press.The grape skins are pressed to release any remaining wine. Pressing gives about 15% more wine!
Maturation. The wines can be stored in a variety of storage vessels including wooden barrels, concrete, glass, clay, and stainless steel tanks. Each vessel affects wine differently as it ages. The oak wood itself flavors the wine with natural compounds that smell like vanilla. Unlined concrete and clay tanks have a softening effect on wine by reducing acidity. Rosè wines are rarely stored in oak.
Blending wine combines different wine varietals to create a composite that improves the taste of wine The wines blended might be from different varieties, different regions, different wood.
Bottling. It’s very important to do this step with as little exposure to oxygen as possible. To help preserve the wine, a small amount of sulfur dioxide is often added.