Agrártudomány | Borászat » Ralph-Patricia - The Art and Chemistry of Wine

Source: http://www.doksinet The Art & Chemistry of Wine Ralph Obenauf President, SPEX CertiPrep Patricia Atkins Applications Specialist, SPEX CertiPrep SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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! SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Ralph Obenauf Making 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. SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Viniculture:

The science and study of all aspects of wine grape cultivation and production SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Varietals Original Barrel of Zin #444 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Chemistry of the Grape 70-90% Water 18-25% Glucose & Fructose 0.3-15% Tartaric & Malic Acids 0.7% Amino acids 0.15% Potassium <0.1% Esters <0.1% Polyphenols Trace Amounts Vitamin A, Vitamin C 2 ½ lbs of Grapes are needed to create a bottle of wine! SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Flavor & Aroma Chemistry of Varietals Compound Methoxypyrazines Examples Odor Earthy, Grassy, Pepper Varietals Cabernet Sauvignon and Sauvignon blanc. 2‐methoxy‐3‐isobutylpyrazine (IBMP) Bell Peppers 2‐methoxy‐3‐isopropylpyrazine (IPMP) Asparagus, Peas, Earth geraniol, linalool and nerol Floral Gewurtramine, Muscat, Riesling megastigmatrienone

zingerone damascenone Spice Spice Rose Oil Chardonnay vanillin Vanilla Monoterpines Norisoprenoids Mercaptans Onion, Garlic Thiols 4‐mercapto‐4‐methylpentan‐2‐one (4MMP), 4‐mercapto‐4‐methylpentan‐2‐ ol, 3‐mercaptohexanol, 3‐mercaptohexyl acetate Glycosides Pinot noir Cabernet Sauvignon, Gewürztraminer, Merlot, Muscat, Petit Manseng, Pinot blanc, Pinot gris, Riesling, Scheurebe, Semillon and Sylvaner Sauvignon blanc Chocolate, Tobacco Ports SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Oenology: The oldest known the science wineryand is located study ofinall Armenia aspectsand wine is over and6000 wine years making old SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX

CertiPrep, Inc. 2011 Source: http://www.doksinet Crushing the Grapes 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 Red Wines • Stems usually removed • Contact with skin encouraged to varying degrees SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet The most Important Chemical Reaction in Wine Making! C6H12O6 2 C2H5OH + 2 CO2 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Fermentation Reactions Bacteria or yeast consumes one compound and excretes different product(s) Fruit (sucrose / fructose / glucose) + Yeast = Alcohol (Ethanol) Milk (lactose) + Bacteria = Cheese Flour (sugars) + Yeast = Bread Ethanol + Yeast = Acetic acid (Vinegar) SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Sugars  Sugar level in wine = ºBrix  1.0º Brix = 1% Sugar = 055% 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 % Alcohol Table 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/winehtml SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 (3.0-37) – 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Chemical Anatomy of the Grape Seeds & Stems (Optional Inclusion) • Tannins Skin • • • • • Anthocyanins Quercetin Resveratrol Tannins Catechins SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX

CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Other Grape Skin & Seed

Compounds  Quercertin − Flavanoid − Antioxidant − Found in skin of grape − Reacts with anthocyanins • deeper vibrant color  Resveratrol (3,5,4-trihydroxy-transstilbene) − 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Chemical Anatomy of the Grape Peripheral Zone Intermediate Zone • Tartaric Acid • Sugars • • • • • • • Potassium Sugars Oxidases Acids Astringents Tannins Aroma Compounds Central Zone • Malic Acid • Sugars SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Other Acids Lactic 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 Acid • Very small quantities in wine • Supplement

for sucrose addition SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Other Acids Acetic Acid • Produced during or after fermentation • Vinegar taste above 300 mg/L • Acetobacter Ascorbic Acid • • • • Vitamin C Found in young grapes Lost to ripening Added with SO2 as antioxidant (EU limit 150 mg/L) Butyric Acid • Bacteria Induced wine fault • Smells like rancid butter or blue cheese Sorbic Acid • Used as a preservative SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Sampling Young Wine SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Chemistry in a Glass 70-90% Water 6-23% Ethanol by Variety 1-3% Pectins, Proteins, Acids 1% Vitamins & Minerals 1% Polyphenols, Flavenoids, Tannins & flavor compounds SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Aging the Wine The average age of a French Oak tree used for wine barrels is 170 years old SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Other Flavor & Aroma influence of the Barrel 

Toasting – exposure of oak barrel to fire & high temperatures – Reduces lactones (fresh oak aromas) – Increases vanilla & caramel aromas Vanillin Furfual 5-methyfurfal – High toast levels = spicy & smoky notes Eugeol & Isoeugenol (spicy) 4-methyl guaiacol (spicy & smoky) Guaiacol (smoky)  Add oak chips to increase aromas SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Racking the Wine Barking at the moon referred to a process of racking the wine under the clear light of the full moon  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. SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Sampling SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Bottles Volume (liters) # Standard Bottles 0.1875 0.25 0.375 0.378 0.5 0.62 0.75 0.757 1.5 2.25 3 4.5 6 9 9 12 0.25 0.33 0.5 0.505 0.67 0.83 1 1.01 2 3 4 6 8 12 12 16 15 20 18 20 25 27 30 24 26.66 33.33 36 40 Name Piccolo Chopine Demi Tenth Jennie Clavelin Standard Fifth Magnum Marie Jeanne Jeroboam Rehoboam Methuselah Mordechai Salmanazar Balthazar  Shape: traditional, cultural or marketing  Before corks bottles were squat & flat bottomed  After corks: store on side: long & cylindrical Nebuchadnezzar Melchior Solomon Sovereign Primat Melchizedek SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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” SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Cork Taint Standards Single Component: Part# Compound S-133 S-1885 S-1983 S-1985 S-2050 S-2930 S-2950 S-3405 S-3555 S-3586 S-3645 S-4168 S-4183 S-4309 S-5005 S-609 Acetic Acid Ethanol 2-Ethylphenol 4-Ethylphenol 2-Fluorophenol 2,3,4,5,6-Pentachloroanisole Pentachlorophenol 2,3,4,6-Tetrachlorophenol 2,4,6-Tribromophenol 2,4,6-Trichloroanisole 2,4,6-Trichlorophenol Malic Acid 4-Ethyl-2-Methoxyphenol 2,4,6-Tribromoanisole Dextrose 2,3-Butanedione Multi-Component: Part# WINE-1 WINE-2 WINE-3 Compound

2,4,6-Tribromoanisole-d5 Pentachloroanisole-d3 2,4,6-Trichloroanisole-d5 2,3,4,5,6-Pentachloroanisole 2,3,4,6-Tetrachloroanisole 2,4,6-Trichloroanisole Carbon Disulfide Ethyl Sulfide Ethanethiol Ethyl Disulfide Ethyl Methyl Sulfide 2-Ethylthiophene Methanethiol Methyl Disulfide Methyl Sulfide 2-Methyl-2-Propanethiol 2-Methylthiophene 1-Pentanethiol 2-Propanethiol Thiophene SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Storage Titanic sits at 12,000 to 13,000 feet below the oceans surface. Many of the wine bottles in the cellar were intact.  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 increase Ideal: 10 to 15 °C – Humidity (75%): corks from drying  Wine refrigerators or Wine cellars keep constant light, temperature & humidity SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Enjoy Breathing

the wine: removes hydrogen sulfides from stinky or young reds; rarely helps whites SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Health Benefits Food & Wine Magazine’s 8 Benefits of Drinking Wine (2007) Reduces Heart Attack rate •30% lower risk (Harvard Public Health Study) Promotes Longevity •34% lower mortality rate (Finnish Study) Lowers Heart Disease •Queen Mary University, London Reduces Risk of Type 2 Diabetes •30% lower risk (Amsterdam VU Univ. Medical Center) Lowers Risk of Stroke •Clot risk drops 50% (Columbia University) Cuts Risk of Cataracts •32% risk reduction (Nature 2003) Cuts Risk of Colon Cancer •45% risk reduction (especially red) (Stony Brook) Slows Brain Decline •Reduced risk (Columbia University) SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Calories in Wine & Alcohol  Recent studies report alcohol is not efficiently metabolized in the body  To calculate the metabolized calories (N): N = T –

(7cal/g)*(0.28g/oz%)*PX = T- 2PX N = net calories T = Total calories X = #oz P = % Alcohol Dry Wine (4oz, 13% abv) Beer (12oz, 5.5% abv) Light Beer (12oz, 4% abv) T=115, N=9 calories T=150, N=18 calories T=105, N=9 calories SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep Pesticide Standards: Part# S-3970 S-5225 S-4622 Pesticide Dimethomorph Pyrimethanil Cyprodinil Part# S-3984 S-4962 S-4815 Pesticide Azoxystrobin Fenhexamid Boscalid S-3871 S-2056 S-2272 S-733 S-2061 S-103 S-3450 Procymidone Tebuconazole Iprodione Carbendazim Fludioxonil Bromopropylate Tetradifon S-2369 S-1997 S-5469 S-4262 S-4267 S-4832 Metalaxyl Fenarimol Spiroxamine Benalaxyl Penconazole Flusilazole

SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet 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 SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Questions?

SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet New in 2011 2011-2012 Catalog – Now available on CD! New Consumer Safety standards kit for USP 232 (Part# USP-TXM1) Visit www.spexcertiprepcom for more information! SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Connect with us! Come visit us on your favorite social networking site! facebook.com/spexcertiprep @spexcertiprep youtube.com/spexcertiprep SPEX CertiPrep, Inc. 2011 Source: http://www.doksinet Thank You! Visit us online at www.spexcertiprepcom SPEX CertiPrep, Inc. 2011