Newcomers to wine often find it confusing that wine rarely smells or tastes like grapes.

Most white wines smell more of tree fruits like apples or peaches, while red wines more often taste more like berries or cherries. One reason why is that grapes taste less distinctive than some other fruits, with a flavor that is less immediately recognizable than that of an orange or pineapple, for instance.

The other factor at play is that during fermentation, countless smaller chemical reactions trigger.

This generates flavor compounds like esters and aldehydes that add new flavors and scents to the wine, flavors which may not have been present or detectable in the fresh fruit. Exotic terms are often used to describe these non-grape aromatics, usually by naming other fruits, foods or spices that they resemble.

But these are not ingredients added during winemaking, just metaphors used to characterize wine’s diverse scents by likening them to more familiar flavors and scents from elsewhere.

Wine is produced through fermentation, a process in which living yeast cultures convert sugar into alcohol.

Fermentation is what makes wine aromatically complex and enjoyable, much the way it does for cheeses. The unique flavors of French Brie, Wisconsin Cheddar and Italian Gorgonzola derive entirely from fermentation and aging, not from their raw material — cow’s milk.

Since yeasts can significantly alter the flavors and scents found in their raw materials, vintners and cheesemakers alike choose their yeast strains carefully, to exert control over how their finished products will taste and smell. Think of yeast as the magic pixie dust that transforms the humble grape into much more flavorful and complex wine.

Feature photo by Kym Ellis on Unsplash.

Marnie Old is one of the country’s leading wine educators. Formerly the director of wine studies for Manhattan’s French Culinary Institute, she currently serves as director of vinlightenment for Boisset Collection and is best known for her visually engaging books published by DK: the award-winning infographic Wine: A Tasting Course for beginners and the tongue-in-cheek He Said Beer, She Said Wine. Read her recent piece, Why We Decant Certain Wines.