The Art & Chemistry of Wine - Organic Standards · Patricia Atkins Applications Specialist, SPEX CertiPrep The Art & Chemistry of Wine ... Flavor & Aroma Chemistry of Varietals Compound

© SPEX CertiPrep, Inc. 2011

Ralph ObenaufPresident, SPEX CertiPrep

Patricia AtkinsApplications Specialist, SPEX CertiPrep

The Art & Chemistry of Wine


Housekeeping

Everyone in attendance will receive a copy of the slides

The webinar is being recorded and will be available for everyone to view on demand

– The recording will be posted about one week after the event

Questions will be answered at the end of the presentation

– Type any questions you may have into the question box and we will answer them during the Q & A portion

Stay tuned after the Q&A session – we’re giving away a free gift!


Ralph ObenaufMaking wine and making merry………..with some chemistry thrown in.

As Ben Franklin said:In wine there is wisdom,

In beer there is freedom,In water there is bacteria.


Viniculture: The science and study of all aspects of wine grape cultivation and production

Viniculture: The science and study of all aspects of wine grape cultivation and production


Harvesting the Grapes

A grape’s terroir : affects of season, weather, soil, mineral, time of harvest, pruning method and acidity = quality, aroma & flavor

Harvest time = grape’s level – sugar (ºBrix) usually >15%

• Later harvest = more sugar– Acid Levels - Tartaric acid– pH

Other harvest factors:– Tannin development (seed color & taste)

De-stemming (removal of stems) depends on winemaking techniques– Stems and seeds = tannins

• White wines – stems intact

• Red wines – stems removed


Varietals

Original Barrel of Zin #444


Varietals

Over 10,000 varieties of grapes in world Vitis vinifera

– Most common species of grapes – Almost all the European varieties– Every continent except Antarctica

Vitis silvestris: ancestor of modern wine Grape Uses

– 71% Wine– 27% Fresh Fruit– 2% Dried fruit

Top wine production regions: Italy, France, Spain, US & Argentina Grafting Root Stocks


Chemistry of the Grape

70-90% Water70-90% Water

18-25% Glucose & Fructose

18-25% Glucose & Fructose

0.3-1.5% Tartaric & Malic Acids

0.3-1.5% Tartaric & Malic Acids

0.7% Amino acids0.7% Amino acids

0.15% Potassium0.15% Potassium

<0.1% Esters<0.1% Esters

<0.1% Polyphenols <0.1% Polyphenols

Trace Amounts Vitamin A, Vitamin C

Trace Amounts Vitamin A, Vitamin C

2 ½ lbs of Grapes are needed to create a bottle of wine!


Flavor & Aroma Chemistry of VarietalsCompound Examples Odor Varietals

Methoxypyrazines Earthy, Grassy, Pepper Cabernet Sauvignon and Sauvignon blanc.

2‐methoxy‐3‐isobutylpyrazine (IBMP) Bell Peppers

2‐methoxy‐3‐isopropylpyrazine (IPMP) Asparagus, Peas, Earth

Monoterpinesgeraniol, linalool and nerol Floral Gewurtramine, Muscat, Riesling

Norisoprenoids megastigmatrienone Spice Chardonnayzingerone Spice

damascenone Rose Oil Pinot noir

vanillin Vanilla

Thiols

Mercaptans Onion, Garlic

Cabernet Sauvignon, Gewürztraminer, Merlot, Muscat,

Petit Manseng, Pinot blanc,Pinot gris, Riesling, Scheurebe,

Semillon and Sylvaner

4‐mercapto‐4‐methylpentan‐2‐one (4MMP), 4‐mercapto‐4‐methylpentan‐2‐ol, 3‐mercaptohexanol, 3‐mercaptohexyl

acetate

Sauvignon blanc

Glycosides Chocolate, Tobacco Ports


Oenology: the science and study of all aspects wine and wine making

Oenology: the science and study of all aspects wine and wine making

The oldest known winery is located in Armenia and is over 6000 years old

The oldest known winery is located in Armenia and is over 6000 years old


Crushing the Grapes

Crushing = start liberation of juice from grape The Must = juice, skins,

seeds, pulp Must contains molds &

native yeasts– Natural is not better

Grape components crushed = winemaking method & variety of wine


Crushing the Grapes

White Wines• Stems can be Intact:

• Increases tannins• Reduces exposure to color in skins • Skins directly removed

White Wines• Stems can be Intact:

• Increases tannins• Reduces exposure to color in skins • Skins directly removed

Rose Wines• Red skinned grapes with minimal skin contact• White & red grapes

Rose Wines• Red skinned grapes with minimal skin contact• White & red grapes

Red Wines• Stems usually removed

• Contact with skin encouraged to varying degrees

Red Wines• Stems usually removed

• Contact with skin encouraged to varying degrees


Potassium metabisulfite & SO2

Added during many stages– Campden tablets = ½ g potassium or sodium

metabisulfite Levels in wine

– Commercial wine = 20 to 40 ppm– Natural wines as low as 6 ppm

• Obie’s wines: no added sulfites; drink within 3-4 years

Produces SO2

− Kills native yeast = antimicrobial

− Anti-oxidant

• Binds w/ acetaldehyde

• Binds w/ anthocyanins

• red wine = problem

• Anthocyanins bind to tannins


Sulfites

K2S2O5, contributes to sulfites in wine ‘Contains Sulfites’ = added sulfite

compounds– Warning labels

• 1987 US

• 2005 EU All wines have sulfites

– Sweet & White > Reds– Fermentation process = 6 to 40 ppm

sulfites– US levels allowed = 350 ppm


Red Wine Headaches

Occurs after drinking red wine

− As little as one glass Usually blamed on sulfites− Only 0.01% population are allergic

to sulfites = asthmatics Un-metabolized acetaldehyde causes

headaches Possible other causes:

− Histamines

− Tannins• Cause release of serotonin

− Prostaglandin release• Cause pain and swelling

− Strains of yeast or bacteria


Punching Down the Must ‘Cap’ – skins, seeds etc. top of juice - CO2 Punching down the must

– Juice mix with skins = color & flavor extraction

– introduce O2 to yeast = fermentation– prevent harmful bacterial growth– lower the must temperature

• Preserve delicate aroma compounds• Increases production of esters• Keep yeast growing

Red wines: 22 to 25° C

White wines: 15 to 18° C Cultured, selected yeast added

– Beginning of primary fermentation

• 1-2 weeks

• Converts most of sugar to ethanol


The most Important Chemical Reaction in Wine Making!

C6H12O6 → 2 C2H5OH + 2 CO2


Fermentation Reactions

Milk (lactose)

+ Bacteria

= Cheese

Milk (lactose)

+ Bacteria

= Cheese

Flour (sugars)

+ Yeast

= Bread

Flour (sugars)

+ Yeast

= Bread

Fruit (sucrose / fructose / glucose)

+ Yeast

= Alcohol

(Ethanol)

Fruit (sucrose / fructose / glucose)

+ Yeast

= Alcohol

(Ethanol)

Ethanol +

Yeast =

Acetic acid (Vinegar)

Ethanol +

Yeast =

Acetic acid (Vinegar)

Bacteria or yeast consumes one compound and excretes different product(s)


Sugars

Sugar level in wine = ºBrix 1.0º Brix = 1% Sugar = 0.55%

EtOH Sugar level = alcohol content Sugars = 1º fuel fermentation Non-fermentable sugars (5 C ring)

– Arabinose, Rhamnose & Xylose– Still present after fermentation– No wine is ever completely ‘dry’

Chaptalization: Sucrose added to boost fermentable sugar content –boost alcohol content– 17-18% alcohol highest level

w/o added sucrose


Fermentable Sugars (6 C ring)

Glucose

− One of primary sugars of wine

− 1st sugar metabolized by yeast

− Tastes < sweet than Fructose

− % Glucose beginning of ripening of grape (>5x Fructose)

− At harvest glucose = Fructose Fructose

− Over ripen grapes > Fructose

− Twice as sweet as glucose• Important for dessert wines

Sucrose

− Minimal in wine, except champagne & sparkling wines


Alcohol - Ethanol Alcohol content limited to 18% w/o

sucrose addition During fermentation, >9% Alcohol

needed to prevent bacterial growth– Mother of Vinegar (Acetobacter)

Target alcohol = 13% Alcohol (24º Brix) Final Ethanol Content varies by variety

Wine % AlcoholTable Wine 8-14%

Claret 6-10%

Shiraz 10-14%

Rose 10%

White, medium 11%

White, dry 11%

Red, medium 12%

White, sparkling 12%

White, sweet 12%

Cabernet, Pinot Noir 11–14%

Dessert Wine 14-20%

Zinfandel 17-22%

Vermouth 17-22%

Syrah 17-23%

Port 20%http://alcoholcontents.com/wine/wine.html


Pressing the Grape Pressure removes juice from pulp & skins Gains 15-30% more juice Pressed juice has lower acidity (higher pH)

than drained juice Red wines pressed after fermentation White wines pressed before fermentation Pressing releases different compounds

from layers of the grape pH adjusted (3.0-3.7)

– Tartaric or Malic Acid– Prevents bacterial growth– Gives tart flavor or zing

<1º Brix before pumping into barrel– Sweet wine >1º Brix

• Stabilized with Potassium Sorbate

Bubbler at top of barrel to release CO2


Chemical Anatomy of the Grape

Seeds & Stems (Optional Inclusion)Seeds & Stems (Optional Inclusion)• Tannins

SkinSkin

• Anthocyanins• Quercetin• Resveratrol• Tannins• Catechins


Grape Skin & Seed Compounds: Tannins

Plant polyphenol Binds and precipitates proteins & other compounds 3 types: hydrolysable, condensed & complex Bad tannins (skins, seeds & stems)

− Don’t polymerize− Produce bitter taste = astringency

Beneficial Tannins (Oak barrels)− Preservative− Wine clarification (Fining agents)

• Proteins bind to tannins • Clarify wine: egg whites, gelatin, bentonite

− Young Oak barrels = more tannins Red wines (>tannins) pair with meats = hydrolysable tannins As tannins age – lose binding

− fall to bottom of bottle− wine mellows


Grape Skin & Seed Compounds: Catechins

Flavanols Also found in chocolate React with tannins to make primary

flavor components in wine Larger flavanol – tannin complexes –

mellow Smaller flavanol – tannin complexes –

bitter Concentrations in red wine 10 mg/L to

250 mg/L− Lighter bodied wine > catechin

content


Grape Skin & Seed Compounds: Anthocyanins

Water soluble pigments of red, purple or blue (pH) Flavenoids Antioxidants Odorless and almost flavorless Polymerize with tannins Important in tannin retention and aging

of wine Five groups of anthocyanins and

presence dependent on varietal of grape & wine− > free hydroxyl groups = blueness− > methyl groups = redness− Malvin group – red grapes


Other Grape Skin & Seed Compounds

Quercertin − Flavanoid− Antioxidant− Found in skin of grape− Reacts with anthocyanins

• deeper vibrant color

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) − Phenol produced by plants when

under attack by bacteria and fungi− Found on skin of grape− Antioxidant works in conjunction

with Quercertin− Reported health benefits


Other Grape Skin & Seed Compounds

Gallic Acid: Phenolic compound − Antifungal & Antiviral compound− Found in seeds & from exposure to new oak− 10 – 100 g/L in wine

Succinic Acid: Dicarboxylic acid− Considered flavor component− Salty bitter flavor in wine elsewhere for

sweetness− Reacts to form esters− Acid + Ethanol = mono-ethyl succinate (fruit

aroma)− In grape & by-product of alcohol and sugar rxn

Caffeic Acid & Caftaric Acid: Cinnamates− Yellow gold color in white wine− Esterifcation rxn: Caffeic Acid + Tartaric Acid =

Caftaric Acid− Oxidation > reaction

• Pressed wine have little to no Caftaric Acid


Chemical Anatomy of the Grape

Peripheral ZonePeripheral Zone

• Potassium• Sugars• Oxidases• Acids• Astringents• Tannins• Aroma Compounds

Central ZoneCentral Zone

• Malic Acid• Sugars

Intermediate ZoneIntermediate Zone

• Tartaric Acid• Sugars


Grape Flesh Compounds:Acids

Acids are important in winemaking and the finished wine Primary Acids in Wine

− Malic Acid− Tartaric Acid

Other Acids in Wine− Acetic Acid− Ascorbic Acid− Butyric Acid− Citric Acid− Lactic Acid− Sorbic Acid


Grape Flesh Compounds:Tartaric Acid

Most important acid in wine Maintains chemical stability of wine Influences Taste & Color Grape vines -few sources of natural

high concentrations Majority of acid = potassium acid salt

(cream of tartar) During fermentation acid binds with

pulp debris (lees), tannins, and pigments Acid crystals can precipitate out

− Wine Diamonds− Cold stabilization precipitates

crystals


Grape Flesh Compounds:Malic Acid

One of two Primary Acids in Wine Carboxylic Diacid Bitter, Tart taste Associated with Green Apple Flavor Riesling – high Malic Acid Cooler growing conditions > Malic Acid Decreases as grape ripens Low Malic Acid = flat taste High Malic Acid = sharp bite


Other Acids

Lactic AcidLactic Acid

• Controlled by the winemaker• Milder than Tartaric or Malic Acid• Creates milky flavor• Rxn Lactic acid bacteria (LAB) &

Malic Acid• Chardonnays & other white

wines • Some LAB -histamines cause

RWH

Citric AcidCitric Acid

• Very small quantities in wine• Supplement for sucrose addition


Other Acids

Acetic AcidAcetic Acid

• Produced during or after fermentation• Vinegar taste above 300 mg/L• Acetobacter

Ascorbic AcidAscorbic Acid

• Vitamin C• Found in young grapes• Lost to ripening• Added with SO2 as antioxidant (EU limit 150

mg/L)

Butyric AcidButyric Acid

• Bacteria Induced wine fault• Smells like rancid butter or blue cheese

Sorbic AcidSorbic Acid

• Used as a preservative


Sampling Young Wine


Chemistry in a Glass

70-90% Water70-90% Water

6-23% Ethanol by Variety

6-23% Ethanol by Variety

1-3% Pectins, Proteins, Acids1-3% Pectins, Proteins, Acids

1% Vitamins & Minerals

1% Vitamins & Minerals

1% Polyphenols, Flavenoids, Tannins & flavor compounds

1% Polyphenols, Flavenoids, Tannins & flavor compounds


Aging the Wine

The average age of a French Oak tree used for wine barrels

is 170 years old


Oak Barrels

Two major origins for Oak barrels– French & American

Seasoning– French oak traditionally aged or

seasoned for two years– American oak kiln dried

Harvest– French Oak is split– American Oak is sawed

• Ruptures xylem cells = release of lactones

Flavor: American Oak > French Oak– 2-4x > lactones – vanilla


Oak Barrels First widespread use - Roman Empire 400 species of Oak 20 species used for wine barrels One tree = 2 barrels 5% of the trees used for barrels Oak barrels are source for tannins

– New barrels = high tannins– Green oak = bad tannins

Porousness: oxidation & evaporation– 5-6 gal loss (59 gal barrel)– Angel’s Share

3-5 vintages before oak character absent – Staves sanded to open oak– Oak strips added to impart aroma


Other Flavor & Aroma influence of the Barrel

Toasting – exposure of oak barrel to fire & high temperatures– Reduces lactones (fresh oak

aromas)– Increases vanilla & caramel

aromasVanillinFurfual5-methyfurfal

– High toast levels = spicy & smoky notes

Eugeol & Isoeugenol (spicy)4-methyl guaiacol (spicy &

smoky)Guaiacol (smoky)

Add oak chips to increase aromas


Racking the Wine

Racking: Separate the wine from the solids, “lees”, settled at the bottom of the barrel

Clearing: Settling of small particulates and matter in wine over time.

Barking at the moon referred to a process of racking the wine under the clear light of the full moon


Sampling


Bottling Process

Bottle Rinsing– Rinsed with Potassium

metabisulfate

Bottles Filling– Wine dispensed into

bottles

Corks are placed in the bottles– Headspace

Capsules placed on bottles– Heat sealed


BottlesVolume (liters) # Standard Bottles Name

0.1875 0.25 Piccolo 0.25 0.33 Chopine

0.375 0.5 Demi 0.378 0.505 Tenth 0.5 0.67 Jennie 0.62 0.83 Clavelin0.75 1 Standard

0.757 1.01 Fifth 1.5 2 Magnum 2.25 3 Marie Jeanne

3 4 Jeroboam4.5 6 Rehoboam6 8 Methuselah 9 12 Mordechai 9 12 Salmanazar

12 16 Balthazar

15 20 Nebuchadnezzar

18 24 Melchior 20 26.66 Solomon 25 33.33 Sovereign 27 36 Primat30 40 Melchizedek

Shape: traditional, cultural or marketing Before corks bottles were squat &

flat bottomed After corks: store on side: long &

cylindrical


Corks

The primary tree for corks is the Cork Oak, Quercus suber Trees are 25 years old before

cork is stripped from the trunks every ten years The trees live for about 200

years Cork production

− 52.5% Portugal− 29.5% Spain− 5.5% Italy


Cork Taint “Corked Wine”

− Cork industry claims only 0.7 –1.2% cork taint

Trichlorophenol compounds Found in cork & methylated by fungi Product is 2,4,6 trichloroanisole, TCA

Damp moldy odor Human detection limit of TCA is 1ppt Eliminate with synthetic corks, screw

caps– Also eliminates the “POP”


Cork Taint Standards

Part# CompoundS-133 Acetic AcidS-1885 EthanolS-1983 2-EthylphenolS-1985 4-EthylphenolS-2050 2-FluorophenolS-2930 2,3,4,5,6-PentachloroanisoleS-2950 PentachlorophenolS-3405 2,3,4,6-TetrachlorophenolS-3555 2,4,6-TribromophenolS-3586 2,4,6-TrichloroanisoleS-3645 2,4,6-TrichlorophenolS-4168 Malic AcidS-4183 4-Ethyl-2-MethoxyphenolS-4309 2,4,6-TribromoanisoleS-5005 DextroseS-609 2,3-Butanedione

Part# Compound

WINE-12,4,6-Tribromoanisole-d5

Pentachloroanisole-d32,4,6-Trichloroanisole-d5

WINE-22,3,4,5,6-Pentachloroanisole2,3,4,6-Tetrachloroanisole

2,4,6-Trichloroanisole

WINE-3

Carbon DisulfideEthyl SulfideEthanethiol

Ethyl DisulfideEthyl Methyl Sulfide

2-EthylthiopheneMethanethiol

Methyl DisulfideMethyl Sulfide

2-Methyl-2-Propanethiol2-Methylthiophene

1-Pentanethiol2-Propanethiol

Thiophene

Single Component:

Multi-Component:


Storage

Most modern wines are consumed within 24 hours after purchase (near term consumption) Most important factors:

– Light: light rxn with phenolic compounds

– Temperature:Chemical rxns 2x every 8 °C increaseIdeal: 10 to 15 °C

– Humidity (75%): corks from drying Wine refrigerators or Wine cellars keep

constant light, temperature & humidity

Titanic sits at 12,000 to 13,000 feet below the ocean's surface. Many of the wine bottles in the cellar were intact.


Enjoy

Breathing the wine: removes hydrogen sulfides from stinky or young reds; rarely helps whites


Health BenefitsFood & Wine Magazine’s 8 Benefits of Drinking Wine (2007)

Reduces Heart Attack rate•30% lower risk (Harvard Public Health Study)Reduces Heart Attack rate•30% lower risk (Harvard Public Health Study)

Promotes Longevity•34% lower mortality rate (Finnish Study)Promotes Longevity•34% lower mortality rate (Finnish Study)

Lowers Heart Disease•Queen Mary University, LondonLowers Heart Disease•Queen Mary University, London

Reduces Risk of Type 2 Diabetes•30% lower risk (Amsterdam VU Univ. Medical Center)Reduces Risk of Type 2 Diabetes•30% lower risk (Amsterdam VU Univ. Medical Center)

Lowers Risk of Stroke•Clot risk drops 50% (Columbia University)Lowers Risk of Stroke•Clot risk drops 50% (Columbia University)

Cuts Risk of Cataracts•32% risk reduction (Nature 2003)Cuts Risk of Cataracts•32% risk reduction (Nature 2003)

Cuts Risk of Colon Cancer•45% risk reduction (especially red) (Stony Brook)Cuts Risk of Colon Cancer•45% risk reduction (especially red) (Stony Brook)

Slows Brain Decline•Reduced risk (Columbia University)Slows Brain Decline•Reduced risk (Columbia University)


Calories in Wine & Alcohol

T=115, N=9 caloriesT=115, N=9 calories

Dry Wine (4oz, 13% abv)

T=150, N=18 caloriesT=150, N=18 calories

Beer (12oz, 5.5% abv)

T=105, N=9 calories T=105, N=9 calories

Light Beer (12oz, 4% abv)

Recent studies report alcohol is not efficiently metabolized in the body

To calculate the metabolized calories (N):N = T – (7cal/g)*(0.28g/oz%)*P*X = T- 2*P*X

N = net caloriesT = Total caloriesX = #ozP = % Alcohol


Pesticides in Wine Grapes: one of the ‘Dirty Dozen’ of produce 2008 Pesticide Action Network (PAN) Europe:

– 128 pesticide residues in 40 bottles EU wine– Low ppm to ppb range

Studies being conducted to find out if the pesticide levels are of concern in wine

Part# Pesticide Part# PesticideS-3970 Dimethomorph S-3984 AzoxystrobinS-5225 Pyrimethanil S-4962 FenhexamidS-4622 Cyprodinil S-4815 BoscalidS-3871 Procymidone S-2369 MetalaxylS-2056 Tebuconazole S-1997 FenarimolS-2272 Iprodione S-5469 SpiroxamineS-733 Carbendazim S-4262 Benalaxyl

S-2061 Fludioxonil S-4267 PenconazoleS-103 Bromopropylate S-4832 Flusilazole

S-3450 Tetradifon

SPEX CertiPrep Pesticide Standards:


Heavy Metals in Wine

Studies have found Hazardous levels of metals in wine– Exceed EPA THQ (Target

Hazard Quotients)• Vanadium• Copper• Manganese• Zinc• Chromium• Nickel• Lead

Worst countries for metal levels:– Hungary, Slovakia, France,

Austria, Spain, Germany, Portugal, Greece


Heavy Metals Standards

SPEX CertiPrep carries full line of Inorganic standards− Heavy Metal Mixes− Heavy Metal Standards

UL and A2LA Stamp of Approval:− Certified by UL-DQS for ISO 9001− Accredited by A2LA for ISO 17025

and ISO Guide 34 Inorganic CRMs for:

− AA & GFAA− ICP & ICP-MS− IC − XRF − Classical Wet Chemistry Techniques

Single element standards 1,000 mg/L and 10,000 mg/L concentrations

Custom standards at almost any concentration


Questions?


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The Art & Chemistry of Wine - Organic Standards · Patricia Atkins Applications Specialist, SPEX CertiPrep The Art & Chemistry of Wine ... Flavor & Aroma Chemistry of Varietals Compound

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