So far, we've learned that wine gets it flavor from three things - the grapes, fermentation and aging. Last time we looked at the fermentation process and how the yeast can affect flavor. But before we move on to flavors associated with aging, let's take a step back to the first item that affects a wine's flavor - the grapes.
While the juice of the grape plays a leading role in the flavors of a wine, the other parts of a grape also can play a supporting role. Items such as the stems from the bunch of grapes, the grape skins and the seeds.
These grape solids are all potential modifiers of the finished wine's flavor. These grape solids contain tannins, proteins and other microscopic solids that can benefit the final product. But, other solids such as leaves, sticks from the grape vine and dirt are undesirable solids that are always removed (For reference, these undesirable items are often referred to as MOG: Materials Other than Grapes.)
With respect to the stems that the grapes were grown on, winemakers can decide if they want to de-stem the grapes before the wine making process begins. White wines are usually made from de-stemmed grapes. But, a red wine’s tannin is increased by leaving some or all of the stems in the juice.
Grape skins also contain flavor compounds. And, just like brewing a cup of tea, the longer you leave the grape skins in contact with the juice, the bolder the flavors can become. The depth of color of a wine also comes from the length of time the wine is left in contact with the skins. For example, if you remove the skins immediately, no color is imparted to the wine. The best example of this is Champagne, a sparkling white wine, that is produced from Chardonnay grapes (a white wine grape), and Pinot Noir grapes and Pinot Meunier grapes that are both red wine grapes. Another example is rosé wines that are made from red wine grapes that see very little skin contact time after pressing resulting in the light pink color.
The grape seeds will also play a role in the wine's flavor as it ferments because they too contain tannin that adds structure and makes wines better able to be aged.
So, it's not just the juice from the grape that affect the flavor of the wine. These other solids play a very important role.
Next time we'll take a look at the final process that affects a wine's flavor, the aging process.
Until then, Cheers!