Did You Know - Wines are Heavily Influenced by Esters, Isoprenoids, Thiols and Phenols?

Photo by Yohan Marion on Unsplash

Winemaking is a fascinating blend of science and art. We’ll dive deeper into the art of winemaking in a future blog, but for now, let’s explore some of the chemistry behind it.

During the winemaking process, several chemical compounds are produced that can greatly impact the wine’s aroma and flavor. These compounds include esters, isoprenoids, thiols, and phenols. Let’s take a closer look at each of them:

Esters

Esters are organic compounds formed by the interaction of alcohols and acids during fermentation and as a wine ages in the bottle. They are responsible for fruity, floral, and sweet aromas in wine.

  • Common Esters in Wine:

    • Ethyl Acetate: Produces fruity aromas (or major wine faults!).

    • Isoamyl Acetate: Responsible for pear drop candy flavors and banana-like aromas (Especially Nouveau Beaujolais)

    • Ethyl Hexanoate: Yields pineapple, apple, or pear-like aromas.

    • Phenylethyl Acetate: Gives floral (e.g., rose), fruity and honey-like aromas.

Isoprenoids

Isoprenoids, also known as terpenoids, are aromatic compounds found in wine. They contribute to floral, herbal, and citrusy notes. Certain grape varieties are more prone to producing specific isoprenoids, which is why some wines are renowned for their distinctive floral or citrus aromas..

  • Examples of Isoprenoids in Wine:

    • Linalool: Creates a floral, lavender-like scent (Esp. in Muscat and Gewürztraminer)

    • Geraniol: Yields a floral (rose-like) scent, found in many white wines.

    • Citrus terpenes (limonene): Contributes to citrusy aromas (Esp. in Sauvignon Blanc)

Thiols

Thiols, also known as mercaptans, are sulfur-containing compounds that can both enhance and detract from wine’s aroma. In small amounts, they impart complex, fruity, and tropical notes, reminiscent of passion fruit, grapefruit, or guava (particularly in white wines).

However, thiols can also contribute unpleasant aromas when present in higher concentrations, often associated with the “rotten egg” smell indicative of sulfur contamination..

  • Key Thiols in Wine:

    • 3-Mercaptohexanol: This compound is responsible for grapefruit, passion fruit, and boxwood aromas (Esp. in Sauvignon Blanc)

    • 4-Mercapto-4-methyl-2-penatanone: Contributes to tropical fruit aromas (Esp. in Sauvignon wines)

Phenols

Phenolic compounds, a diverse group of chemical compounds, encompass both volatile and non-volatile components. In wine, they primarily contribute to astringency, bitterness, and color. Additionally, they enhance the wine’s aging potential and are often associated with potential health benefits. Phenols can originate from grape skins and seeds, as well as from oak barrels utilized in winemaking processes.

  • Flavonoids (e.g., anthocyanins): Contributes to the color of red wines and potential health benefits.

  • Tannins: These are found mainly in red wines, and they contribute to the mouthfeel and the structure of the wine.

  • Resveratrol: Known for its potential health benefits, resveratrol is a phenolic compound found in the skin of red grapes and has antioxidant properties.

So, in summary, esters contribute fruity and floral aromas, isoprenoids add distinctive floral and citrus notes, thiols impart tropical and fruity characteristics, and phenols influence color, taste, mouthfeel, and aging potential. Each of these compounds plays a crucial role in shaping the complexity and character of wine, with their levels and interactions being influenced by grape variety, terroir, and winemaking techniques.

Behind the Cork™ - Sweet Wines of Oliver Winery for Valentine's Day

Oliver Winery, located in Bloomington Indiana, is “Driven by curiosity and creativity” according to Rob Warren, VP of Winemaking. This ‘hobby winery’ has grown to be among the 30 largest wineries in the U.S. They seek to set the quality standard for the sweet and flavored wine category with innovative yet approachable wines - unpretentious, full of personality and refreshingly real - No flavorings or colorings, no high fructose corn syrup.

Oliver wines are:

  • Giftable: Bright, bold flavors make these wines a thoughtful and approachable gift for wine enthusiasts and casual drinkers alike

  • Chocolate Pairing Perfection: Dreamberry and Cosmoberry complement a variety of chocolates, while the Sweet Red pairs with everything from truffles to chocolate-covered pretzels

  • Celebration-Ready: Whether for a party or romantic dinner, these wines are festive, fruit-forward options

The ‘Soft Wine Collection’ from Oliver Winery (including the three featured wines below) is crafted with juice from the cool-growing Great Lakes region and cold fermented in stainless steel tanks resulting in a bright fruit taste and aroma.

Oliver Winery - Sweet Red ($13)

Ranked one of the Top 6 sweet red wines in the U.S.

Classic Concord grape aroma, deliciously smooth, fruity taste, and ruby-red color. This soft red wine is fresh, crisp, and just-sweet-enough.



Oliver Winery - Dreamberry ($16)

This wine has layered real flavors of light and tropical lychee and raspberry with sweet red wine and a hint of lime. A refreshingly real, deliciously juicy wine. Made with the very best fruit and natural ingredients.



Oliver Winery - Cosmoberry ($16)

Inspired by the classic Cosmopolitan cocktail, this berry-infused sweet red wine has a familiar Concord-based red wine a twist, with a bright balance of natural cranberry, strawberry, and blood orange. Cosmoberry is a smooth, easy-to-drink wine.

For 50 years, Oliver Winery wines has represented the highest-quality ingredients. Their winemakers continually refine each wine in their portfolio to create approachable, fruit-forward, flavorful wines you can enjoy again and again. Cheers!

Disclosure of Wine Sample Submission: I received these samples at no cost for review.

Media Samples Provided by Oliver Winery

Ever Wonder? What Does Total Acidity and pH Mean in a Wine?

Acids are a key component of wine, alongside tannin, alcohol, and sugar. They contribute to the wine’s freshness, act as a preservative, and help keep the microbes in check. Acidity also gives wine its tart and sour taste.

There are two main ways to measure acidity in wine: Total Acidity, which is measured in grams per liter (g/L), and pH (Potential of hydrogen). pH measures the concentration of hydrogen ions in a solution, and it’s a dimensionless measure. It’s also important to note that pH is a logarithmic scale, so a wine with a pH of 3 is ten times more acidic than a wine with a pH of 4.

Total acidity is measured in grams of tartaric acid per liter of wine. But, while tartaric acid is the main acid in wine, other like malic acid, citric acid, and lactic acid also be present.

Total acidity tells us how much acid is in the wine, while pH tells us how acidic it tastes.

In general, all wines are acidic. Here are some examples:

  • White Wines:

    • pH ranges from 2.5 to 3.5 (lower pH make them taste crisp, bright and fresh)

    • Total Acidity:

      • Low acidity: 4.5 to 5.0 g/L (e.g., Chardonnay)

      • Medium acidity: 5.0 to 6.5 g/L (e.g., Sauvignon Blanc or Pinot Grigio)

      • High acidity: 6.5 to 9.0 g/L or more (e.g., Albariño or Riesling)

  • Red Wines:

    • pH ranges from 3.5 to 4.5 (higher pH makes them taste softer and rounder)

    • Total Acidity:

      • Low acidity: 4.5 to 5.5 g/L (e.g., Merlot or Zinfandel)

      • Medium acidity: 5.5 to 7.0 g/L (e.g., Cabernet Sauvignon or Syrah)

      • High acidity: 7.0 to 8.5 g/L or more (e.g., Pinot Noir or Barbera)

  • Sparkling Wines:

    • pH ranges from 3.3 to 3.8

    • Total Acidity: Often in the range of 7.0 to 9.0 g/L

So, in summary, Total Acidity tells us how much acid is in the wine while pH tells us about how the wine will taste and feel in our mouth. Cheers!

Behind the Cork™ - Chile's Coastal Pinot Noir

As we’ve learned, Chile’s coastal wine country is heavily influenced by the Humboldt Current. Here are three excellent examples of the Pinot Noir being produced along Chile’s coast.

2022 Concha Y Toro “Amelia” Pinot Noir ($55)

The grapes for this wine are grown on the northern bank of the Limarí River at an altitude of more than 600 feet above sea level, just about 14 miles from the Pacific Ocean. The temperatures are cool and the mornings are cloudy, so the fruit ripens slowly, producing fresher tasting wines. This Pinot Noir is produced from 50% whole clusters that are fermented in stainless steel tanks. After Malolactic Conversion, the wine remains in French oak barrels (10% new) for 12 months. This Amelia Pinot Noir is medium purple in color with delicate fruit aromas. On the palate, this Amelia Pinot Noir is light in flavor with medium acidity and finishes easy. (ABV: 14%, TA: 4.5 g/L, pH: 3.63, RS: 2.74 g/L).

2023 Terranoble “Algarrobo” Pinot Noir ($15)

This wine is named for the iconic Algarrobo tree in their vineyard in the Las Dichas sector of the Casablanca Valley. The grapes for this 10% Pinot Noir are fermented in small batches with ~45% being whole clusters. It is then aged for six months in used barrels and in foudres (22%) before being aged three months in the bottle before release. This Algarrobo Pinot Noir is pale purple in color with aromas of sweet candied cherries and honey. On the palate it is medium-bodied with flavors of cranberry and sour cherry. It finishes a bit tart. (ABV: 13%, TA: 5.6 g/L, pH: 3.53, RS: 2.7 g/L).


2020 Garces Silva “Boya” Pinot Noir ($20)

This Boya (Bouy) Pinot Noir is from the Leyda - San Antonio appellations and produced from three French clone (888, 777, 115). Thee grapes were fermented in stainless steel tanks for 12 to 15 days (10%-20% whole cluster). It was aged in stainless steel, used barrels and concrete tanks. This Boya Pinot Noir is medium ruby with a touch of garnet in color. On the nose it had strong aromas immediately after opening that settled down after decanting. On the palate it was medium-bodied with cherry-cranberry flavors (ABV: 13%, TA: 5.0 g/L, pH: 3.58, RS: 1.8 g/L)



This week, we’re shining a spotlight on three Pinot Noirs from Chile’s coastal regions. These wines are not only delicious but also affordable, making them a great fit as this week’s Behind the Cork™ Wines of the Week. So, grab a glass and let’s toast to these amazing Chilian wines! Cheers!

Disclosure of Wine Sample Submission: I received these samples at no cost for review. The opinions expressed are entirely my own.

Media Samples Provided by Concha Y Toro, Terranoble, Garces Silva and Master the World

The Humboldt Current's Imprint on the Wines of Chile

The Humboldt Current, a chilly current that flows right beside Chile’s coastal wine regions, plays a big role in the climate and how grapes ripen.

Two popular grape varieties, Chardonnay and Pinot Noir, are grown in Chile’s coastal wine regions.

The cold temperatures brought by the Humboldt Current and the reduced sunlight because of thermal inversion slow down grape ripening in a high-latitude area. Wherever vines are planted in this Humboldt-influenced buffer zone, the ripening temperatures are low and similar to those in Rheims, Champagne, and Dijon, Burgundy. But when the sun clears the mist around midday, the sunlight gets stronger, just like it should be in those latitudes.

This mix of cool temperatures and plenty of sunlight makes sure the wines ripen slowly and completely. The whites stay sharp and acidic, with low pH, while the fruity smells are ripe, with notes of apple and pear for Chardonnay, and lime and ginger for Pinot Noir.

The palates are rich even though they’re tart. For Pinot Noir, the color is a bit brighter because of the sunlight, while the crisp smells of sweet and sour cherry mix with wet earth, tart acidity, and a rich palate.

The soils are super important in making the wines. Granite gives most wines a lean and smooth texture, while calcareous clay, especially in Limarí, gives them a chalky feel. Scattered pockets of slate add a more concentrated palate because of the poor, rocky soils.

The combination of the climate of the Humboldt Current and the soils of the Chilean coast creates a super unique terroir. Since it’s so different, it’s fair to consider another name for Chilean coastal wines: Humboldt wines! Cheers!

(Materials provided by The Wines of Chile)