The Anatomy of a Grape

 Grape Expectations

To understand the flavors and aromas in your glass, you need to understand the anatomy of a grape. Start by thinking about grapes that you might snack on from the grocery store: there are different types of table grapes that we mostly refer to as "green," "red" or "purple," and they have different flavors when we bite into them.

The grapes used for wine are very similar, but they are smaller in general and always have seeds, so not quite as satisfying to snack on. Wine grapes can be DNA tested and differentiated by the varietal and growing region, so instead of just "green" or "red" grapes, we have Pinot Noir grapes, Sauvignon Blanc grapes, Tempranillo grapes and so on. Those grapes are used to produce wines of the same name.

Each type of grape grows differently and looks slightly different than other grapes. Some grape skins are golden and translucent, and some are pinky-grey (hello, Pinot Gris), while still others are almost black. Each grape has its own unique juice scent and taste as well, just like those table grapes. A Muscat grape picked off the vine has sweet floral aromas if you break it open and smells very "grapey" while a Pinot Gris grape may smell more like honey (and grapes).

The juice contains tartaric acid and malic acid as they develop in clusters, and the berries produce sugar (glucose and fructose) as they ripen. Sugar is important because that is what is fermented into wine. The seeds and skins have tannins as well as chemical compounds called polyphenols that affect a lot of the aromas and flavors that we perceive in different types of wine.

Yeast is introduced to the grape juice during fermentation. The yeast eats the sugar and converts it to alcohol to make the wine we enjoy.  Each type of grape has different reactions to fermentation, and of course, the way the juice is fermented can affect the resulting wine, but in the wine world we can talk about "typical" flavors and aromas because each grape is unique.

Some juice is fermented in an inert container such as steel which will not have an affect on the flavors as much as oak. Some wines are fermented with the skins in the juice (all reds but some white wines, too) which will add color and flavors to the wine. Skin contact also increases the tannins, or that kind of drying sensation you can get on the inside of your cheeks from a sip of wine.

Quiz time!

What is whole cluster fermentation?

A)  juice that's fermented in small batches, or clusters of containers

B)  juice that's fermented with other clusters of fruit like raspberries or herb bunches

C)  juice that's fermented while still growing on the vine

D)  juice that's fermented with the grape bunches still on the stems

Yes, it's D! 

Red wine is sometimes fermented in the whole cluster and yeast does not (always) have to be introduced because the whole berries will start to ferment themselves. It adds structure and bright fruitiness to the resulting wine. Gamay Beaujolais Nouveau is an example of this. Many winemakers will whole cluster ferment part of a whole batch to add some liveliness, so whole-cluster fermentation can show up in different ways.

Come by Studio Vino to learn some more and taste the difference between grapes for yourself!