The Art of Making Wine by Professor Ron Fournier January 18, 2017

What is Wine ? Principal wine producing countries, as defined by law, says that wine is the fermented juice of grapes – “wine” From other fruits or vegetables add a descriptor such as “blackberry wine” or “apple wine” or “dandelion wine” Juice produced from wine grapes Vitis vinifera over 5000 varieties of this grape have been developed Juice from grapes contains all the stuff needed for fermentation sugar, water, minerals, and even the yeast (wild strains) today these wild yeasts are usually suppressed in favor of special winemaking yeasts Sugars are primarily the monosaccharides glucose and fructose (glucose and fructose are both 6 carbon sugars and when combined they form the disaccharide sucrose)

History of Wine Vitis (grape) found in fossils 15 million years old Primitive cultures made wine 10,000 years ago Organized viniculture occurred in Mesopotamia (Iraq) 5,000 years ago and 6,000 years ago in Armenia Egyptian frescoes show grape gathering and wine production Conversion of something sweet to a dry (non-sweet) liquid, along with the pleasant effects of drinking the fermented juice, and its red color, made folks in ancient times associate wine with magic, the gods, blood and life, and sacred rites that last to this day

History of Wine Records of Greek civilizations 3,500 years ago show that wine was a popular beverage and a sacred drink Dionysus in Greek legend (Baccus by the Romans), the son of Zeus, invented wine on Mt. Nysa in Libya Even the Hebrews think of Noah as the first winemaker as seen in the Old Testament of Genesis (9:20-21); in New Testament Gospel of John, Jesus performed his first miracle and launched His career by turning water into wine (John 2:3-11) at the wedding at Cana Greeks and Romans lined storage vessels with resin which added additional flavors (try some Greek Retsina) Medieval Catholic Church and their monks developed new grape varieties (grain, olive oil, and wine was their livelihood)

Growing Grapes Juice of ripe grapes for wine making contain about 21 to 25 wt % sugar with an acid content less than 1 wt % tartaric, malic, and citric acids Tartaric acid C4H6O6 or HOOC-CH(OH)-CH(OH)-COOH Malic acid C4H6O5 or HOOC-CH2-CH(OH)-COOH Citric acid C6H8O7 or HOOC-CH2-C(OH)(COOH)-CH2-COOH Acids add sharpness and a fruity taste so acidity of wine juice may need adjustment Grapes can be grown in most temperate regions except where winter temperatures are extremely low Vines do not require a rich soil and can thrive in sandy, chalky, rocky soil in sunny locations France and Italy leading producers, over 40% of world’s output Recent reports indicate California will surpass France About 90% of US wine is made in California Local areas include Traverse City, MI area and the Niagara-on-the-Lake region in Canada north of Niagara Falls Australia along with Chile and Argentina becoming important exporters of wine (try a Malbec)

Types of Wines Wines can differ in their flavor, aroma, and alcohol level Characteristics of wine depend on the variety of grape used and chemical composition of the vineyard soil Also depends on the methods used for making the wine Major types of wine include Nonsparkling (still), table, or beverage wines that contain less than 14 % alcohol Sparkling wines such as champagne, less than 14% alcohol Fortified wines, “apertiff” , such as port and sherry, with 16 – 21 % alcohol Sweet or dessert wines such as the Sauternes Aromatic wines such as vermouth (martini’s), with 15 – 20 % alcohol Spirit wines, made by distillation, like brandy Wines are also red, white, or rose’ (pink) Most red and rose’ table wines are “dry” meaning they contain only very small amounts of unfermented sugar, less than 0.1% sugar

Making Wine Making wine involves the processes of collecting the grapes pressing the grapes (skins stay –red wine, skins go – white wine) fermenting the juice (the must) clarifying the wine (racking) caring for the wine until it is ready for bottling Grapes harvested in the fall, 22 wt % sugar in juice 16 lbs of grapes yield 1 gallon of wine Fermentation caused by yeast Saccharomyces cerevisiae (many varieties), anaerobic C6H12O6 ---> 2 C2H5OH + 2 CO2 + Q Theoretical yield YP/S = 0.51 g ethanol/ g glucose Usually get about 90-95% of this because some of the glucose forms biomass and other byproducts such as esters “bouquet”, glycerol “sweetness”, and if not careful undesirable stuff like organic acids such as acetic acid (presence of oxygen) Sulfites (such as potasssium metabisulfite) used to prevent growth of wild yeasts and to prevent oxidation

Making Wine Primary fermentation best at about 70 F and can take 7-14 days, for dry wine sp gr drops from 1.090 to about 1.000 during this time Sp gr a measure of glucose content, also common is the Balling or Brix scale which reads in wt % sugar 0 Balling = 1.000 sp gr 23.9 Balling = 1.100 sp gr Dry red or white wines start with sp gr = 1.09-1.095 or 22-23 Balling, i.e. 22-23 wt % sugar Potential alcohol level then about 13 vol%

Making Wine Wine is then racked into another secondary fermentor and left with an airlock for about 30 days Gets the wine off the “lees” , the dead cells and sediment that can spoil taste Typically one racks the wine 3-4 times Time between each racking about 3 months Then bottle and store / age the wine

Making Wine at Home Commercial wine is no more a “real” wine than one made at home or in our class Grape source Actual grapes Juices Concentrates Kits, usually a juice or concentrate with yeast and other chemicals Better ones require no additional sugar

Grapes

The Crusher

Crushing

Crusher Separates the Stems from the Grapes & Juice

Stems Crushed Red Grapes & Juice Grapes & Juice in Primary Fermentor

White Wine Juice from Press The Press

Winemaking Equipment Primary fermentor; 7-10 gal, food grade poly 2 5 gal glass carboys Siphon Stirring spoons Bottle brush Fermentation locks Measuring cup Hydrometer Thermometer Acid test kit Record book Bottles and corks Nice to have Wine thief Bottle sterilizer Bottle corker $50-$200 typical investment

Making the Wine Primary fermentor shown at right Sanitizer important 3 TBS of potassium metabisulfite to 2 liter of water Sanitizer good for 6 mos. Rinse all equipment with this sanitizer After sanitizing rinse with water

Making the Wine Juices usually of higher quality than can concentrates Heron Bay makes a variety of Juices, 16 L bag in a box, add 7 L of water Here we are making a Cabernet Sauvignon

Making Wine Pour the juice into the primary fermentor Take an initial sp gr reading For example in this case sp gr = 1.34 Add additional water to get sp gr down to 1.09-1.095 Here we add 7 L of water to 23 L final Add oak chips if desired

Making Wine Hydrometer reading tells you how much sugar you have

Making Wine Once the juice is in the fermentor and the sp gr is correct make a yeast starter Always use a cultured commercial wine making yeast Here we are using Red Star brand Pasteur Red A strong, even fermentor, produces a full-bodied wine with fairly complex flavors Good for the Cabernet family of grapes Mix the yeast with some of your juice and let sit for about 30-60 minutes

Checking Acid Content Important to check the acidity - otherwise flat or flabby tasting wine - no crispness and limited longevity, minimizes oxidation - acids interact with the alcohol during aging to produce fruitiness and bouquet - most important acids are tartaric, malic, and citric - use an Acid Blend to adjust acidity to a level of .65 (red) - .7 (white) wt %

Making Wine Next we add some tannin Yeast Nutrient Gives wine some astringency (pucker) or character, sort of a bite Helps wine to clear Prolongs the life Typically 1/8-1/4 tsp per gallon Yeast Nutrient Provides elements and vitamins essential for a healthy fermentation Nitrogen source Otherwise “stuck” ferment

Making Wine After a day or so you should see rather vigorous bubbling and the formation of a cap, do not stir or disturb Check sp gr every few days and continue until sp gr reaches 1.000 Place a loose plastic cover over the fermentor to keep the critters and pests out

Time Schedule Primary fermentation, 7 – 14 days Secondary fermentation, 30 days Rack #1 and wait 2 – 3 months Rack #2 and wait 2 – 3 months Rack #3 and wait 2 -3 months Bottle Enjoy!

Progress of Fermentation Days Days

End of Primary Fermentation Note cap and active foaming Primary fermentation ends when sp gr is 1.000 or less, here it is about 0.995

Rack to Secondary Fermentor Add ½ tsp of Potassium Metabisulfite

Racking Rack the wine into a new carboy every 2 to 3 months Add ½ tsp of Potassium Metabisulfite

Bottle & Enjoy !

References “Winemaking, the Concentrate Method, by Art Lynch “The Art of Making Wine”, by Stanley Anderson and Raymond Hull “The Home Winemaker’s Companion, Secrets, Recipes, and Know-How for Making 115 Great-Tasting Wines,” by Gene Spaziani Best source for winemaking supplies Presque Isle Wine Cellars, www.piwine.com