Frog Blog ~ Are There Raspberries in My Wine?

Do you ever wonder how people can smell and taste cherries, black currants, cedar, roses and even tar in wine?

Are you puzzled by the description of a wine in a tasting note or on the back label of a bottle when you know that only grapes went into the making of that wine?

Luscious apricot and peach notes are firmed up with fresh edges of apple and citrus.

So, where do these wine aromas and flavours come from?

Welcome to the wonderful world of wine chemistry!

First, let’s be clear that discerning a wine’s aroma and flavour are highly personal … meaning that people’s abilities are related to experience. If you haven’t ever tasted lichee fruit, you won’t recognize that aroma/taste in a glass of Gewürtztraminer.

Also, the mechanics of your power of smell and the number of taste buds on your tongue can influence what you can perceive.

Aroma & Flavour Categories:

Most wine aromas and flavours can be organized into categories such as fruit, floral, herbal/vegetal, spice and earth.

They can come from the grapes (primary), the winemaking process (secondary) and from the ageing process (tertiary).

Chemical Sources:

The chemical sources of many of the fragrances and flavours that make up a wine’s profile, as mentioned above, come from interactions among a variety of naturally occurring chemical compounds and released at various stages of the winemaking process. They can be pleasant in small doses and can be wine faults (unpleasant) at higher thresholds.

 

Here are some of the main sources:

Chemical Compound	Aroma/Flavour Profile	Produced How?
volatile organic compounds	buttery, oaky, peppery, vanilla	released during crushing of grapes and alcoholic fermentation
alcohols	green leaves, fresh-cut grass (e.g., C6-alcohols)	released from fruit itself and through yeast fermentation
esters	fruits	from acids and produced by yeasts during fermentation
lactones	vanilla, coconut, roasted hazelnut	type of esters (see above), can come from oak-ageing
pyrazenes	vegetable-like (e.g., bell pepper), herbal	formed during fermentation process as well as from biological reactions of amino acids and sugars
terpenes	floral and citrus	present in grapes, a plant metabolite
rotundone	peppery spice	type of terpene (see above)
thiols	fruit (e.g. grapefruit pith, gooseberries, black currants)	from interaction of yeast on sulphur organic compounds found in grape must
norisoprenoids	petrol or kerosene-like (e.g., TDN)	present in grapes, a plant metabolite
phenolic compounds (flavonoids and non-flavonoids	spice, add texture (e.g., smooth, dusty, silky)	found in grape pulp, skin, seeds and stems
sulphur compounds	earthy, minerality (e.g., rocks, slate, chalk)	present in all stages of wine-making process

Science Buffs, do not hate us! This is a very simplified explanation of complicated chemicals processes.

Please tell us about your experience of tasting wine. What are you able to taste and smell?