Red and White Wine Vinification

by Chris Giellis, Mile High Wine and Spirits

The vinification processes that red and white wines follow include many common steps, but there are some fundamental differences between the two. White wines are fermented without the grape skins and other solids that are incurred during the vinification process. Red wines on the other hand are fermented in contact with the grape skins. The reason for this fundamental difference in the vinification process is the imparting of the grape skin’s color and tannin. The basic wine making procedure is defined by steps that are consistent (in almost all aspects) across varying regions and appellations around the world.

The first step in the vinification process is the crushing and destemming of the grapes. This process is typically done mechanically and the “free run juice” is released. During this step the fruit is separated from the stems to avoid the bitter tannins that can be released from the stems. In white wine vinification, the must (unfermented juice, grape skins, and seeds) is immediately pressed to separate the juice from the skins. The longer that the juice is in contact with the skins there is an increased chance of tannins and color to be imparted during the wine making process. Following the pressing of the grapes, which includes the maceration of the skins, the juice undergoes its primary fermentation.

Primary fermentation consists of the natural sugars of the juice being converted to alcohol and carbon dioxide as a result of either cultured or native yeasts. The majority of white wines ferment in stainless steel tanks to control of the fermentation temperature. However, many fine wines are fermented in small oak barrels. Fermentation of white wines in barrels (normally French oak for chardonnay) typically occurs at higher temperatures while imparting flavors from the barrel. This type of fermentation changes the flavor and other components of the wine. Red wines however follow a different vinification procedure in regards to the fermentation step.

Unlike white wines, the juice of red wine grapes ferment in contact with their skins. The skins impart color and tannins to the juice. After crushing and destemming, the must inoculated with yeast and fermentation takes place and typically for a shorter time period and at higher temperatures than for white wines. During the fermentation step for red wines, the extraction of color, tannin and alcohol are incurred. Following the primary fermentation step some white wines undergo a secondary fermentation called malolactic fermentation and almost all red wines follow this same step. The malic acid that is natural in the wine grapes is converted into lactic acid. This steps happens naturally or through the inoculation of the wine with malolactic bacteria. As an outcome of malolactic fermentation, the wines created are softened and have buttery and vanilla flavors imparted.

Following the secondary fermentation (if utilized) the process of aging is incurred. During this step the wine’s flavors and characteristics develop before it is bottled. Stainless steel aging will preserve a white wine’s fruity characteristics, while aging in barrels promote aromas and flavors, such as spice, toast, and vanilla. Subsequently clarification and bottling will happen. All winemakers want their wines to be clear of any haziness. Several techniques can be utilized to accomplish this including racking, fining, or filtration. After the wine has been clarified it is bottled and can undergo additional aging in the bottle if necessary.

Now that we understand the basic vinification processes for red and white wines let’s sample various a couple of different bottles that have undergone the aforementioned steps. Enjoy!!