Describing the aromas in Galician wines requires a little chemistry lesson. Like all wines, the aromas in albariño, mencía, godello, and more come from volatile flavor compounds that are let loose when mixed with alcohol and can be detected by our noses.
A wine’s aromatic composition comes in part from the decisions in the winery, but it also reflects the variety and the terroir. Even when a grape variety is found in different areas and vinified using various techniques, the resulting wine will have certain qualities inherent to that variety.
I want to break down some aromas and aromatic compounds found in some classic Galician grapes: albariño, treixadura, godello, and mencía. Stay tuned for part 2, where I’ll get into some off-the-beaten-path Galician grapes and what makes them smell the way they do.
Let’s get to it: what do these wines actually smell like?
Albariño can have aromas of citrus fruit like lemon, lime, grapefruit, passionfruit, kumquat, and mandarin orange; stone fruit aromas like apricot and peach; tropical fruit aromas like pineapple; floral aromas like linden flower, orange blossom, and lavender; mineral aromas like sea salt; spice aromas like laurel and saffron; and Albariños with bottle age can develop notes of honey, toast, and kerosene.
Treixadura can have aromas of citrus fruit like grapefruit; tree fruit like quince, apple, and pear; stone fruit like yellow plum, tropical fruit like melon, pineapple, and banana; floral aromas like linden flower, jasmine, honeysuckle, and chamomile; vegetal aromas like hay, dill, and grass; spice aromas like saffron, thyme, and mint; and Treixadura with bottle age can develop notes of honey and kerosene.
Godello can have tree fruit aromas like apples, pears, and quince; stone fruit aromas like peach and yellow plum; citrus aromas like lime; tropical fruit aromas like melon, mango, and passionfruit; vegetal aromas like grass, hay, and ferns; spice aromas like rosemary and dill; Godello with barrel age can have aromas of vanilla and nutmeg; and Godello with bottle age can develop notes of toast, almonds, and kerosene.
Mencía can have red fruit aromas of cherry, strawberry, raspberry, redcurrant, and pomegranate; black fruit aromas like blackcurrant and blackberry; blue fruit aromas like blueberry, floral aromas like rose and violet; vegetal aromas like fern and laurel; spice aromas like black pepper; Mencía with barrel age can have aromas of vanilla, cedar, and smoke; and Mencía with bottle age can have aromas of mushroom and leather.
The main aromatic compounds in Albariño are alcohols, terpenes, C13-norisoprenoids, volatile fatty acids, and volatile phenols. Among these, the compounds most responsible for Albariño’s varietal character are terpenes and C13-norisoprenoids.
Terpenes are natural chemicals found in plants that give them their smell. They’re what make oranges smell citrusy and pine trees smell piney. In wine, terpenes contribute floral, fruity, and herbal aromas and flavors. Terpenes like linalool, geraniol, nerol, limonene, β-citronellol, α-terpineol, 4-terpineol and Ho-trienol all help to give Albariño its fruity and floral aromas. Albariño is a super-terpenic variety—a study of Albariño, Riesling, Muscadelle, and Sauvignon Blanc showed that Albariño was the richest in terpenes.
Norisoprenoids are another class of organic compounds that form form during the grape ripening process and continue to evolve during fermentation and aging. They contribute a range of aromas such as floral, fruity, spicy, and woody notes. Common examples of norisoprenoids in wine include β-ionone, which gives a violet scent, and β-damascenone, which can produce floral, rose-like aromas.
Finally, Albariño has a high percentage of thiols: they’re most associated with tropical and citrus aromas found in Sauvignon Blanc, but they can also create the flint and mineral aromas found in certain examples of the grape.
Other important Albariño aromas and the aromatic compounds that cause them include: limonene (lime/lemon/orange aromas), nerol (floral, lime), linalool (orange/citrus), Ho-trienol (tropical/citrus), α-terpineol (citrus/herbaceous).
As for the other white grapes, there has been very little study done on the aromatic compounds present. We know that both Godello and Treixadura contain some terpenes—that’s what makes all three Galician grapes share citrus notes—but it’s hard to measure how those compounds interact with each other to create aromas detectable by the human nose.
And where Mencía aromas are concerned, gas chromatography studies show that several esters and fatty acids contribute to making Mencía smell the way it does, although those are compounds formed during fermentation and have nothing to do with the variety itself. We can also find gamma-nonalactone, β-citronellol, β-damascenone, and β-ionone in Mencía.
Galicia is still a very young wine-growing area in the modern sense, so we’ll have to wait for more studies to be done before we can fully understand the relationship between aromatic compounds and the many aromas to be found in Galician wines.