This Halloween, I wanted to sink my teeth into something spooky and talk about why some wines taste like blood. This iron, metallic flavor in wine can offer a fun, mineral quality that adds allure and mystery.
So, the bloody taste is not a flaw. It’s a flavor compound found in some wines, especially red wines. Here are some of my favorite bloody wines.
Nebbiolo, especially from Ghemme or Gattinara in Northern Piedmont, Italy, is one of the most famous iron-rich, blood-scented wines. Nebbiolo is incredibly complex with aromas ranging from rose petals to tar. This finicky and late-ripening grape variety slowly develops its signature perfume after months on the cool climate vine.
Some attribute this savory, iron quality found in the wine to its minerality. It tends to be more prevalent when grown in mountainous regions like Gattinara, Ghemme, or Valtellina, where the soils tend to be thinner and more acidic.
Syrah’s hallmark is a spicy, black-pepper quality that the grape gets from rotundone, the same flavor compound found in peppercorn. This thick-skinned red variety is often very savory and has an aroma of charcuterie, meat, and iron. The fruits lean more towards plush black and purple fruits, sometimes giving a blackberry jam sensation with a dusting of fresh ground black pepper.
Some of the most delightfully meaty expressions come from the Northern Rhône, especially from Cornas. Here it’s a bit warmer than the rest of the region due to the amphitheater shape formed by the surrounding hills. These hills protect the vines from cold winds, ripening the Syrah grapes into a powerful expression.
We know this Spanish grape variety best from its expression in Rioja. This is one of the few regions in the world that intentionally holds back their wine and releases it after a fair amount of aging (a minimum of five years for Gran Reserva). Typically, winemakers here age Tempranillo with some new American oak, lending more spice and cedar aromas to the wine (although more are switching to French oak for its softer aromas). American oak has larger pores than French oak, meaning the wines can oxidize more quickly. It also tends to have high levels of volatile acidity, which gives the wine a lifted floral and balsamic aroma. Classic Rioja is beautifully oxidative with roasted black fruits, week-old violets, and that iron-rich, bloody aroma.
Why do some wines taste like blood?
Wine can taste like blood from oxidation, volatile acidity, flavor compounds in grapes, and aroma compounds produced during fermentation. Some argue that wines grown in iron-rich soils, such as clay, can have a bloody aroma. Yet wine professionals hotly debate the role of soil’s real impact on flavor.
Monoterpenes are the largest group of flavor compounds found in grapes. This string of atoms gives grapes, spices, herbs, and flowers each a distinct smell. Monoterpenes are basically enzymes that act as catalysts to bring two molecules together. As grapes mutate, they may develop higher concentrations of these aromas.
Terpene subgroups may influence the flavor as well, such as the sesquiterpene rotundone mentioned earlier. Fermentation may also affect the reaction to the monoterpene enzymes by releasing their attachment to other molecules. In other words, the wine may have a different level of aroma enzymes than the grape itself. (If you want to geek out about this, read more here).
There is still a lot to learn about the chemical breakdown of grape & plant aromas, but we know that particular grapes tend to carry a specific aroma. Their environmental conditions can influence the development of certain smells. For example, a Pinot Noir from Burgundy tends to smell more earthy than a Pinot Noir from California, which is fruitier. The colder climate and higher cloud cover mean that Burgundian Pinot Noir grapes develop and ripen more slowly and lean towards more floral, earthy flavors—less ripe, fruity notes.
Nebbiolo from cool and foggy northern Italy is similarly affected. The aroma develops slowly, drawing out more savory, floral, tobacco, and blood notes. Whereas, the peppery aroma in Syrah or Mourvèdre is inherent in the grape. When combined with other savory aromas, that same spicy, animal, bloody/iron smell is present.
Esters are a group of volatiles created during the process of fermentation. They generally give the wine a fruity smell. When yeast converts the sugar in grapes into alcohol, the grape’s genetic makeup influences whether it produces more ethyl ester (the fruity aroma). A higher level of ethyl ester’s genetic precursor means the wine could smell fruitier. More hexanoic acid means more ethyl hexanoate, resulting in a softer, prettier smell. Think pineapple and banana.
Our other group of esters, acetic esters, give a more lifted, floral, vinegar smell. This is more directly related to the yeast’s alcoholic conversion. There are different strains of saccharomyces cerevisiae, the yeast primarily responsible for vinous fermentation. Different strains seem to have different expressions of the alcohol acetyltransferase gene. So, the number of acetic esters will be higher in some grapes than in others. Ok, wtf does this have to do with vampires?
A grape with lower levels of ethyl ester precursors combined with an environment that produces a yeast strain more prone to releasing acetic ethers will flaunt its earthy, mineral characteristics, such as an aroma of iron & blood. Barolo & Rioja are some of the most lauded expressions of this style.
Volatile Acidity & Oxidation
Volatile acidity occurs when a wine has a high amount of the aforementioned acetic ethers. Specifically, guaiacol is directly associated with a smoky, sometimes irony, or bloody aroma.
Oxidation occurs when the wine is exposed to oxygen, causing the wine to dull in color and lose flavor. It may also release certain pleasant aromas, like hazelnut. In contrast, too much air can convert the acetaldehyde to acetic acid. Once again, you’ll find less fruit and more mineral notes. Red wines that are more prone to oxidation, especially those introduced to oak, will start to show some of those dark, mineral, savory characteristics. Rioja is a classic example of how a bit of oxidation can add a spicy element to the wine.
Is it ok when my wine tastes bloody?
It is entirely up to your preference! Some people prefer to only drink wines with fruity or floral aromas, whereas others find that lifted VA level alluring. It’s an element of mystery and umami that draws you back into the wine, something that smells familiar, but you just can’t quite put your finger on it. It can be a delightful contrast to simple, earthy foods like pasta with truffles. And if you are a vampire, most of these wines age wonderfully, so you can stock your wine for an eternity.