How easy it could be to misinterpret us wine writers when we say a wine is “bursting with black fruit” or “notes of grapefruit and wild strawberries”! And even though most of us, once we’ve developed an interest in wine, understand that the flavors are not actually added to the wine, it still isn’t inherently obvious what brings the flavor of “toasted brioche,” “grass” or “underwood” to your glass. Parts of the most wild descriptive language is more entertainment than precision (who wants to read a boring wine writer?) but there are definitely parts of this language that are quite useful and connected to specific chemical compounds.
Primary, secondary, tertiary
In wine, we speak of primary, secondary and tertiary flavors. Simply put, the primary flavors come from the grape itself and are affected by things such as variety, clone, terroir and ripeness. These flavors include fresh apple, blueberry, raspberry, blackberry and other fruit, berry and herbal flavors. Secondary flavors and aromas come from the winemaking process.
Though most fine wines use neutral yeasts, many rosé wines and fruity, less expensive wines get some extra fruit flavors from aromatic yeasts used in the fermentation process. With that exception, the fermentation gives notes like toast, bread, hard cheese, spice or bacon (caused by low levels of the wild yeast brettanomyces) and vanilla (from newer oak barrels), while the malolactic conversion will mainly add aromas of cream or butter.