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Friday, November 15, 2019

Taste & Aroma Profiles, Part 4

                                    Almond-like flavor is a classic profile of Champagne

This is the final in a four part series on the aromas and flavors of wines produced by chemical reactions during the fermentation process.  In review, we’ve discussed the buttery profile caused by the conversion of harsh malic acid to the softer lactic acid.  Next, the science behind a variety of fruit flavors in wine was detailed, followed by a discussion of the chemistry behind grassy aromas and smells.   This final blog will address another flavor component caused by a chemical reaction during wine-making.  It will also discuss other common flavors present in wine that have nothing to do with the fermentation process, but everything to do with the oak barrel.

Almond nuances are classically associated with sparkling wine.  This almond profile is caused by the release of a chemical component produced by yeasts during fermentation.  Sparkling wines that have rested “on their lees” (i.e. had contact with the dead yeast cells) often have almond aromas and flavors due to the chemical compound benzaldehyde.  This chemical actually has an almond aroma.  Wines that undergo batonnage (frequent stirring and mixing of the lees) also exhibit almond tones.

A final note of clarification:  not all aromas and flavors in wine, however, are related to chemicals produced during fermentation.  Oak barrels can play a huge part in influencing both a wine’s smell and taste.  The following are examples of chemicals in oak that can alter the taste and smell of wine:
  • Eugenol:  responsible for spices such as clove, nutmeg & cinnamon (note that this chemical is actually found in all of these spices)
    Vanillan:  the compound, also found in the vanilla bean, gives off vanilla aromas & flavors
  • Furfural:  imparts dried fruit flavors & coffee nuances (furfural is also found in coffee)
In summary, there are hundreds of chemicals found in wine.  Some occur because of chemical reactions in fermentation; others are present due to other factors (such as the use of oak).   What is interesting to note, however, is that most of these chemicals do not reach the threshold of one being able to distinguish them.  The majority of people have an average threshold for tastes and smells.   However, there are some people, who have a more sensitive threshold and may be able to distinguish tastes and smells more readily than others.

Friday, November 8, 2019

The Science Behind Grass in Your Glass

                     New Zealand's Greywache Sauv Blanc is one of the country's benchmarks
This is the third in a four-part blog series on aromas and flavors in wine that are directly related to chemicals produced during the wine-making process.  Today, we’ll discuss the grassy smell and taste found in wine.  These isn't a figment of your imagination, but is a scientific fact that occurs as a direct result of chemical changes during fermentation.

Have you ever wondered why your Sauvignon Blanc (SB) is reminiscent of freshly mowed grass?  This classical grassiness taste and nose found in many SB’s is due to chemicals called aldehydes.  These compounds, released during fermentation as yeasts turn SB grape sugar into alcohol, evoke the smell of just-cut grass.  The SB grape has  the ability to produce high level of aldehydes.  The perception of grassiness is driven for the simple reason that these same chemicals are also found in grass.  Cutting grass releases these highly fragrant chemicals into the air.

The less ripe the SB grape, the higher the propensity is for aldehydes, and thus the stronger the grassy profile.  New Zealand SB’s are known for their traditional grassy notes.  Kiwi SB’s are purposely picked a little less mature for this reason, but also responsible is the moderate climate where this country’s SB grapes are grown.  The Loire Valley also is famous for SB.  As this area is fairly far north, SB often can’t ripen to its fullest degree, so Lorie wines classically also have grassy nuances.   In contrast, California SB has abundant sun and generally is picked more mature.  This translates to less intense grassy nuances.  In Cali’s warmer growing areas, SB’s actually can take on ripe tropical notes.

Next week we’ll finish this series by discussing one of the common flavors in sparkling wine which is also caused by the science during fermentation.

Friday, November 1, 2019

How Can Wine Smell like a Banana?

                 Banana, green apple & gooseberry profiles are the result of chemical reactions

Why in the world does a wine taste or smell like any fruit other than a grape?  This is the second article in a blog series on the science behind certain flavors and aromas in wine.  This particular article will discuss three fruit flavors/fragrances that can appear in wine.  In fermentation, yeasts eat the sugar in the grapes and convert it to alcohol.  In this process thousands of various chemical compounds are produced.  All three fruit flavors below are a result of these complex chemical processes.

The banana-like smell and taste is a result of a chemical compound by the name of isoamyl acetate, a by-product of yeasts during fermentation.  The isoamyl acetate also occurs naturally in the banana plant, as well as in pears.  It is present in most wines, however, it is below the threshold of one’s ability to taste it.  It should come as no surprise that artificial banana flavoring is made from isoamyl acetate.

This banana smell and taste can appear in both white and red wines.  Aromatic white wines that are fermented at cooler temperatures (lower temperature enhances the amounts of isoamyl acetate) often display ripe banana notes.  For example, that banana nuances can often be found in Chardonnay, Pinot Gris and Albarino.  Beaujolais is one of the few red wines that has a banana profile.

Green Apple
This flavor and smell profile found in wines is due to the lactic acid which is created during malo-lactic fermentation.  Lactic acid gives off green apple-like scents and flavors, in addition to a creamy mouth feel.  Wines that have pronounced green apple character are classically cool climate dry whites such as Chardonnay, Riesling and Gruner Veltliner.

Like green apples and banana nuances, this flavor and aroma is not part of the grape.  Gooseberry is created during alcoholic fermentation and is a by-product of yeast activity.   This fruit is typically less sweet so its taste is on the tart side (think pucker),  but gooseberries can also have a slightly floral scent.  Generally found in aromatic whites, gooseberry is classically associated with Sauvignon Blanc (particularly those from cool weather regions such as coastal New Zealand, or France’s Loire Valley).

Keep in mind that each person has a different innate level of tasting various substances.  It doesn’t matter what you taste or don’t taste in a wine.  The only thing that counts is if it pleases you.

Friday, October 25, 2019

Understanding “Buttery” Wines

                         Luscious, unctuous & buttery whites are magic caused by chemistry 

Ever wonder what’s the reason you smell or taste certain flavors in wine?   How do things such as “coffee,” “green apples” or “grass” appear in wine?  This is the first in a series of blogs on the science behind how these and other aromas and flavors develop.  Let’s start with “buttery,” a term often used to describe a certain style of California Chardonnay (although other white wines such as Marsanne or Roussane can also exhibit buttery characteristics).

The butter profile is caused by a common chemical reaction in wine-making called malo-lactic fermentation (ML).  During ML, bacteria converts harsh malic acid to the much softer lactic acid.  In this chemical reaction a compound by the name of diacetyl is produced.  Diacetyl is also found in dairy products like butter (diacetyl is even added to artificial butter to make it taste more like the real-deal product).
Butter nuances can be created, as well as manipulated, by certain interventions of the winemaker.   For example, winemakers can actually control the amount of butter-like character in a wine.  Different strains of ML bacteria produce different amounts of diacetyl so winemakers can pick and choose depending on what style of wine they want to create.  Winemakers can also control ML fermentation by raising and lowering the fermenting wine's temperature:  warmer temperatures activate ML, while cooler temps stop ML fermentation and arrest the production of the butter-like compound diacetyl.

The term buttery is used not only to describe flavor and aromas of wine,  but it is also used to describe the almost oily, unctuous texture of a wine.  Think creamy like cream...a smoother, rounder mouth feel.  This velvety texture is also a result of ML, and the diacetyl produced changes the feeling to that of a more dairy-like substance.  Buttery California Chars have this hallmark velvet-like texture.

There’s another factor that can create the buttery profile.  Aging in newer oak barrels imparts flavors and aromas but can also add to the creamy texture beyond that of ML.  The newer the barrel and the longer the wine is in contact with the oak, the more intense the butter and creaminess.  Stirring of the lees (batonnage), can also enhance buttery flavors.

Whatever the science, buttery preference is in the eyes of the beholder.  Some like it, others don’t.  Personally, I can swing both ways.  Some of my fave big fat buttery Chars are Dehlinger (Sonoma) and Cakebread (Napa).   

Friday, October 18, 2019

New Zealand---Benchmark for Quality/Price

                      Some of the world's best white wine values wine are in New Zealand

Outstanding quality and value wines can be found around the globe.   New Zealand, however, consistently knocks it out of the park for quality-to-price ratio.  For example, nearly 130 Kiwi wines recently reviewed by the Wine Spectator earned scores between 90-100 points, and the average price rang in at only 37 US bucks per bottle. Conversely, California Cabernets with the same Wine Spectator scores were $145 per bottle, while Cali Pinots were $63.  Similarly, high scoring South African wines (which are a huge value at the moment) were an average of $53 on Wine Spectator. 

Currently, Wine.Com (the world’s largest online store), lists a dozen New Zealand wines with Robert Parker scores of above 90 points for < $30---the majority are less than $20 and are Sauv Blancs., another behemoth of the internet wine world, also gives New Zealand major props for their high quality/low price wines.  In their recent World’s Top 50 Wine Bargains, several of them were from New Zealand.  Wine Enthusiast Magazine, lists three New Zealand Sauv Blancs in their Top 100 Best Buys which featured bargains from around the globe.  Forbe’s Magazine named New Zealand in 2017 as one of the most underrated wine regions. 

If you are coming with Wine-Knows to New Zealand for their harvest in February 2020, you’ll note that while the country has many pricey wines >$100 US, it also abounds with delightful values of superbly crafted wines.  Below are some of my fave quality/price Kiwi wines, all of which are available in the US.  Two are reds, but the remainder are whites.

  • Ata Rangi Sauv Blanc   
  • Greywacke Sauv Blanc
  • Greywacke Pinot Gris
  • Loveblock Sauv Blanc
  • Whitehaven Sauv Blanc 
  • Villa Maria Cellar Selection Sauv Blanc

  • Cloudy Bay Sauv Blanc
  • Quartz Reef Sparkling Brut
  • Te Mata Cape Crest Sauv Blanc
  • Trinity Hill Gimlett Gravels Syrah

  • Greywacke Pinot Noir
  • Te Mata Elston Chardonnay


Friday, October 11, 2019

Buried Treasure---Truffles

                     Truffles grow underground & specially trained dogs are required to find them

October is the beginning of the season for the world’s most expensive culinary treasure, the white truffle.  Only grown in a small area near the Italian Alps called Piedmont, the white truffle (tartufo bianco) is the most fragrant and most intensely flavored of all of the many varieties of truffles.  For this reason it is often called the “King of truffles.”  Its step-sister, the not-as-fragrant-black truffle, is grown in several parts of the world, but it is the highly prized white truffle which gourmands around the world not only covet, but pay mega Euros to feast on this buried edible masterpiece.

                             The tartufo bianco is the most aromatic & flavorful of all truffles

All truffles are a type of an exotic fungus that grows underneath the ground near the roots of certain trees.  In Piedmont, Italy the white truffle variety grows commonly near the roots of hazelnut, oak, pine or beech trees.  Truffles, a kind of distant cousin of wild mushrooms, are found by special dogs who have been trained to smell these highly fragrant edibles which are concealed several inches under the forest’s floor.

Piedmont in October is one big love-fest with the white truffle.  The charming medieval town of Alba is home to the Truffle Festival, a decadent food gala celebrating the area’s famous white culinary diamonds.  Weekends are grid-lock with aficionados from around the world descending on Alba for a smell and taste of the intoxicating white truffle.   There is pageantry with parades, music, and dance---all to honor the illustrious tartufo bianco.  

                                     Alba's Truffle Festival is a do not miss event for foodies

 If you can’t make it to Piedmont for the Truffle Festival, the next best thing may be dining at a Michelin star restaurant somewhere in the world during the months of October or November.    Be prepared, however, to spend almost $100 more per dish for the addition of the white truffle.  This means a $50 pasta will become $150 with the tartufo bianco.

Buon appetito!

Friday, October 4, 2019

The World’s Most Widely Planted Grape?

There are over 10,000 grapes on the earth, but not all of them are used in making wine. While numbers vary, most would agree that at least 1,000 of them are currently used to make wine.  Now, make a guess as to what wine grape is the most planted varietal.   If you guessed Merlot, you’re close…. it’s second.  If you guessed Cabernet Sauvignon you are right!  Cabernet Sauvignon accounts for >5% of the grapes for wine production around the globe.  There are more than Cabernet vines than both Pinot Noir and Syrah and plantings combined.

You may have been lucky on choosing Cabernet, however, for the most planted white wine grape varietal, what’s your guess?   Chances are >99% of you guessed incorrectly.  For white wine grapes, the world’s most widely planted variety is Airen.  That’s right…Airen.    This grape ranks 4th among both red and white wine grapes.  It is surpassed only by Cab, Merlot, and Tempranillo.  Airen vines account for more than both Pinot Noir and Sauv Blanc combined.

Airen is grown almost exclusively in Spain.  Up until a few years ago it was the world’s most widely planted grape.  If you’ve never heard of it, it’s because Airen is often used for Spain’s unpretentious wines.   The last five years, however, many of the Airen vines have been ripped out and replaced with Tempranillo, another grape native to Spain.    That being said, Airen and Tempranillo combined currently account for 45% of all of Spain’s wine grapes.

Below is a list of the Top Ten wine grape varietals across the globe:

1.     Cabernet Sauvignon
2.     Merlot
3.     Tempranillo
4.     Airen
5.     Chardonnay
6.     Syrah
7.     Grenache
8.     Sauvignon Blanc
9.     Pinot Noir
10.  Trebbiano (also called Ugni Blanc)