Course:FNH200/2012w Team15 GrapeWine

A Glass of Red Wine

Red Wine is an alcoholic beverage derived from a wide variety of wine grapes. There are many different kinds of ‘red’ grapes, ranging in color from red to deep purple to light blue. The color of the grape is largely due to the skin, and will influence the color and flavor of the wine, as the skin of the grapes contain both color and tannins. Red grapes is also said to typically produce a more complex wine than white wine grapes, due to their longer growing season in warmer climates. The most common varieties of red wine are: Barbera, Cabernet savugnon, Chianti, Malbec, Merlot, Pinot Noir, Sangiovese, Syrah, and Zinfandel, all of which are named after the grapes used to produce the wine. Wines with a light red color are classified as rosé wines, and are typically made from very dark purple grapes whose skin is removed. Sparking wines, which can be made from practically any variety of wine grape, are wines that contain carbon dioxide bubbles that form naturally during the fermentation process and kept in the wine by the winemaker(s). Desert wines are those red wine with especially high sugar content, often due to purposefully late harvests or by first concentrating flavors by drying the grapes before wine production. Red wine contains roughly 25 calories per ounce, and a typical single serving of wine is roughly 5-6 ounces. Red wines range in price from under ten dollars to hundreds (if not thousands, depending on the obscurity and age of the wine). Regions that produce the greatest amount of red wine include Northern California, France, Italy, Spain, Argentina, and Australia.

Viticulture

Viticulture describes the production and study of grape cultivation.

Grape Growth in a Vineyard

In order to create high quality wine, grapes used are grown under optimal environment. Contributing factors towards this environment include: management of soil, water and irrigation, proper climate. Of these many factors which determine the health and quality of grapes, selecting the growth site of grapes is possibly the most significant step, because the site determines the presence and quality of all the contributing factors. The growth sites must have an adequate water supply, appropriate soil fertility, good exposure to the sun, and optimal (moderate) climate conditions. If the site does not receive enough rain, there must be irrigation water, as well as water drainage so that the amount of water is balanced, thereby preventing of water deficiency or soil erosions. As for soil quality, coarse, textured soils such as sand or loam soils are most suitable for growing grapes due to their ability to provide maximum oxygen for the grape roots and best water drainage. It is nearly impossible to claim that a certain region is most ideal for grape production, because climate conditions, soil fertility, and water availability vary over the course of the year, and may even vary year-to-year. For example, whether the vineyard site is planted on a north-facing, south-facing, west or east facing slope of a mountain or hill could be an advantage or disadvantage depending on the season. Nonetheless, it is best that wine grapes receive a good amount of sunlight, as solar radiation determines the amount of natural sugar produced.

Harvested Wine Grapes

Likewise, climate conditions affect grape composition, thereby affecting the quality of the grapes. Grapes low in acid and high in sugar are considered to be of high quality. In terms of the most ideal temperature that grapes should grow under, it is best to avoid winter temperatures that are below zero degrees Celsius, because these temperatures (around -20 degrees Celsius) could severely damage grape growth, especially in British Columbia. Many times, viticulturalists will spray their grapes with water before temperatures reach below freezing, as the water will crystallize around the grapes, keeping them at 0°C, rather than exposing them to the colder outside air, as air temperatures drop. There is some good news for British Columbian viticulturalists; according to an article by CBC News of Canada written in July of 2012, winters in BC are getting warmer and local climatologist Tony SHaw says, “we’re not seeing as many days with sub-zero temperatures that are harmful to viticulture.” This climate change is ideally beneficial because Canada’s extreme winter temperatures were the number one limiting factor to grape growth.

Fermentation

Preparation of the grapes

Prior to the process of fertilization, a few steps must occur in order to prepare the grapes. First determine the type of wine is desired, if red then the skin of the grape must remain intact, however if white then the skin is removed. For our particular case, we only focus on the process of red wine making. Next, the chosen grapes are placed on a conveyer belt where they are sorted, and the debris is removed. The conveyer leads the fresh grapes into a machine called crusher-destemmer where, as the name suggests, the grapes are cracked and the stems are removed. This results in a slurry of berry juices and skins which is known as the must.

Cold-Juice Maceration and Hot-Extraction

Once the must is formed it is sent to the fermentor, a large oak or stainless steel vat where fermentation occurs. However, before fermentation, two optional processes may occur according to the winery. First, is the cold-juice maceration where the must is cooled to prevent oxidation and formation of unwanted strains of yeast. Second treatment is the hot-extraction, when initially placed into the fermentor the must is heated to enhance the pigments. In situations where there enough is not enough sugar, chaptalization is required where additional sugar is added to the must to meet the minimum amount.

Post-addition of Yeast

Involvement of Yeast

Yeast are critically chosen for winemaking because they have an influence on the flavor and aroma of wine. Depending on the winemaker, the amount and type of yeast can greatly influence their desired wine by producing sweet smelling compounds. Unfortunately, yeasts are also capable of producing compounds that remove desirable characteristics from wine and are often referred as 'taints'. For instance, wild yeast, Kloeckera apiculata, is capable of producing ethanol to approximately four to five percent, however they produce aldehydes that detract from the wine's bouquet. The most common yeast chosen for the winemaking is process is Saccharomyces cerevisiae, due to its ability to produce large amounts of alcohol without being affected, it produces limited amounts of taints and almost exclusively produce alcohol as a by product. The entire fermentation process is done in anoxic environment, primarily because in an oxygenated environment yeast preferentially respire.

Process of Fermentation

Once the minimum amount of sugar is met, yeast is chosen and added then fermentation begins. The enzymes in the yeast converts the available sugars in the must to ethanol and carbon dioxide. The process is executed in temperatures of twenty to thirty degrees in either refrigeration units or with insulation jackets surround the fermentors. Fermentation continues for 6 to 7 days until the wine is 'dry', or until all the sugar is consumed. With minimal amounts of sugar in the must, the yeast can no longer sustain themselves and eventually die off, sinking to the bottom. The end product of fermentation is the 'lees' where then it is siphoned or racked off into bottles.

Changes during Fermentation

Sediments of Grapes left

During fermentation, a few issues may occur. For instance, due to differing densities between skins and juices of the grapes a cap may form on the surface of the must. This is negative to winemaking, because it limits the amount of flavor and aroma compounds in the final product. In order to eliminate the cap, it is either punched down or the juice is either pumped over.

Lactic Acid Fermentation

Another form of fermentation done by a different strain of yeast occurs when the wine is racked into the bottles. A highly acidic and anoxic environment is created and the yeast Leuconostoc enos is capable of fermenting the lactic acid to malic acid. This results in some desirable aromas compounds and increases the complexity of the wine. However, this fermentation process is done under careful management because high amounts of lactic acid fermentation can result in an undesirable wine.

Post-Fermentation

Finally, once wine maker is content with the wine produced, they add sulphur dioxide prior to bottling which inactivates any remaining yeast in the product. Furthermore, sulphur dioxide inactivates acetobacter, a bacteria that breaks down ethanol in an oxygenated environment yielding acetic acid. Acetobacter is the most common wine spoiling agent.

Packaging & Storage

Red wine juice pressed out

Following the fermentation process, the grape juice (now wine) is pressed out of the holding tanks, where it sits for several days to allow for the particles, sediments, and dead yeast cells to settle to the bottom and filter out. Once winemakers have determined that the wine is free of any particulate matter, the wine is then put into barrels to begin the aging process.

Packaging Step 1: Aging

Wine Barrels

Wine barrels are essential in the winemaking process, allowing the wine to age, oxidize, and alter the flavor due to components in the wood barrels. Wine barrels are made almost exclusively from oak, but may sometimes use redwood or even chestnut. Oak barrels are said to give red wines a bit of a vanillin and spicy flavor, although the amount of spice and vanillin flavor it partially determined by the age of the barrel, the amount of time spent aging, and the type of oak (or other wood) used. Wine aging in barrels can take anywhere between several months and several years, depending on the type of wine and the winemaker’s preference. Once the wine is initially added to the wooden barrels, which hold roughly 59 gallons of wine, several gallons (about 3-4) are absorbed into the new wooden barrels. Throughout the following aging process, winemakers will lose close to another gallon due to evaporation losses and oxidation aging. Wooden wine barrels allow for a limited amount of air and liquid to escape from the barrel without allowing the wine to spoil or become overexposed to the air. The evaporation of water and alcohol concentrates the flavor and aroma compounds that make up the unique flavor of each type of wine. Once barrels have been used to age wine, the wine-soaked wood in the barrels can often turn to vinegar, which takes only a few days. These barrels can become contaminated with bacteria and are often discarded due to the incredible difficulty that goes along with trying to sterilize a wooden barrel (it is nearly impossible).

Residues of Grapes after filtering

Many large-scale commercial winemakers avoid this by leaving wine in the barrels until the next batch of fermented wine is ready to be aged.

Packaging Step 2: Bottling

Once the wine has aged for the proper amount of time, it should be stable and clear, and free of CO2, it is ready to be bottled. A wine is clear when it is free of particles that may later settle at the bottom of the bottle, and will not continue to ferment and produce CO2, which (if left in the wine) can cause pressure to build up in the bottles, which can cause bottles to break, corks to pop out, or wine to be unnecessarily ‘fizzy’. A wine is stable when it has enough sulfites present in the wine to ensure the wine will not oxidize or spoil. In the commercial production of red wine, bottles are filled by a sanitary siphon hose and rod, which fills each bottle carefully to prevent future oxidation (from stirring to vigorously) and to the same level. Finally, a cork (made from Cork Oak, Quercus Suber) is placed in the top of the bottle to compress the remaining air and prevent the wine from oxidizing or spoiling before it reaches the consumer.

Advantages of Drinking Red Wine

Health Benefits

Resveratrol

Red wine, in moderation, has well known health benefits.
As a result of everyday toxic substances such as air pollution, smoking, or even poor nutritional choices, free radical molecules develop in our bodies. These ‘incomplete’ molecules strive to be complete, and will therefore attach to other healthy cells and steal an oxygen atom from full molecules. The resveratrol is the key ingredient in red wine that is considered a powerful antioxidant, and is found in the skin of grapes. Resveratrol can actually repair cells that have been damaged by free radicals and reduce the risk of diseases such as diabetes, osteoporosis and certain types of cancer. It helps to reduce our bodies’ production of LDL, low density lipoprotein which is sometimes referred to as “bad” cholesterol, because excess LDL ends up getting deposited in arterial walls and forming plaque, which causes arteries to stiffen, resulting in higher blood pressure, and ultimately causing heart attacks.

Moderate amounts are beneficial to health

Another health benefit of resveratrol is its ability to regulate nitric acid levels in the human body. Nitric oxide is a gas that enables muscles to relax, and relaxation helps to prevent the formation of blood clots in arteries. Another nutrient that can be found in red wine is flavonoid, it is also an anti-cariogenic or cancer fighting molecules, and it prevents cancer forming agents from reaching healthy cells and suppresses malignant. Moreover, red wine can help from getting the flu since the antioxidants in wine are believed to fight infection, and can reduce a person’s chances of getting influenza by 20 percent.

Vitamins and Minerals

Red wine also contains small amount of vitamins and minerals such as potassium, which helps to regulate the heartbeat and convert blood sugar into glycogen. Wine also contains Fluoride, which helps prevent tooth decay, and phosphorous which helps convert food into energy and helps with kidney function and heart muscle contraction. Many scientists believe that the positives of drinking red wine go beyond cardiovascular benefits.

Other functions

In fact, there are other alternatives uses for wine aside from human consumption. First of all, wine can be sprayed on our fruits or vegetables to remove impurities, and the alcohol can even function as an antibacterial treatment. Secondly, wine can be an excellent base for jelly, and it’s very easy to make it at home because just it simply mix water, pectin and fruit with the wine. Moreover, wine is commonly added when we cook steak. It is perfect to pair them together because the opposition between fatty sensation of the steak and astringent sensation of the wine make the food more delicious.

Disadvantages of Drinking Red Wine

Food-borne Diseases

Red wine are known to contain tannin. Tannin is a water-soluble polyphenol found commonly in plants. In terms of health defects, tannin is considered to have low nutritional value due to its inhibitory effect on food digestion and conversion of absorbed nutrients to newly synthesized body substances. Certain cancers, such as mouth, throat, and gullet cancer, as well as, breast cancer in women are reported to be associated with alcohol consumption in large amounts. However, red wine has only about 8% of alcohol, relatively low compared with other alcohol beverages. And, it is not experimentally proved that these carcinogenic activities are directly related to tannin itself, not other closely associated components of tannin. In addition, tannin is shown to reduce the mutagenic activities of certain mutagens in human body which is likely because of its anti-oxidative property. There is still a debate whether tannin is carcinogenic or anti-carcinogenic. Tannin also contributes to migraine, a chronic headache. The symptoms of migraine can vary from moderate to severe.
In terms of health benefit, tannin is an antimicrobial agent which inhibits the growth of many disease-causing yeast, fungi, bacteria and virus. Drinking red wine can prevent infections of the type of foodborne diseases that are caused by growth of certain microorganisms in host.
Another problematic component of red wine is sulfite. It is estimated that one out of a hundred people are allergic to this, i.e., sulfite sensitivity. Sulfite is an inclusive word of sulfur dioxide (SO2). It is added during processing as a preservative in wine, based on its antioxidative and antimicrobial properties, similar to tannin. However, for a person who is sensitive to sulfite, severity of the symptoms can vary from mild to life-threatening. If you are allergic to sulfite, avoid drinking red wine or any other alcohol beverages use sulfite as a preservative. Read the labels carefully.

Red Wine in Canada: Rules & Regulations

Final Product: Red Wine

In Canada, wine is produced mainly in four provinces: Ontario, BC, Quebec, and Nova Scotia. However, small fruit wine operations can be found in New Brunswick, Newfoundland, and Prince Edward Island. The regulations of wine production and sale vary from province to province. However, minimum standards of production along with the area of viticulture have been set by the national Vintners Quality Alliance (VQA). The regulations include designated origin of grapes and grape-type-specific minimum sugar values. The reception of the VQA seal requires tests by a lab and independent panel for quality assurance.
Under the Canadian Food and Drug Regulations, wine is an alcoholic beverage produced by fermentation of fresh grapes. The following may be added to wine during the manufacturing process:

• (i) yeast,
• (ii) concentrated grape juice,
• (iii) dextrose, fructose, glucose or glucose solids, invert sugar, sugar, or aqueous solutions of any of them,
• (iv) yeast foods, in accordance with Table XIV to section B.16.100,
• (v) calcium sulphate in such quantity that the content of soluble sulphates in the finished wine shall not exceed 0.2 per cent weight by volume calculated as potassium sulphate,
• (vi) calcium carbonate in such quantity that the content of tartaric acid in the finished wine shall not be less than 0.15 per cent weight by volume,
• (vii) sulphurous acid, including salts thereof, in such quantity that its content in the finished wine shall not exceed
  • (A) 70 parts per million in the free state, or
  • (B) 350 parts per million in the combined state, calculated as sulphur dioxide,
• (viii) any of the following substances:
  • (A) citric acid, fumaric acid, lactic acid, malic acid, potassium bicarbonate, potassium carbonate, potassium citrate and tartaric acid, at a maximum level of use consistent with good manufacturing practice,
  • (B) metatartaric acid at a maximum level of use of 0.01 per cent, and
  • (C) potassium acid tartrate at a maximum level of use of 0.42 per cent,
• (ix) amylase and pectinase at a maximum level of use consistent with good manufacturing practice,
• (x) ascorbic acid or erythorbic acid, or their salts, at a maximum level of use consistent with good manufacturing practice,
• (xi) antifoaming agents, in accordance with Table VIII to section B.16.100,
• (xii) any of the following fining agents:
  • (A) activated carbon, albumen, casein, clay, diatomaceous earth, egg-white, isinglass, polyvinylpolypyrrolidone and silicon dioxide,
  • (B) acacia gum, agar, gelatin and potassium ferrocyanide, at a maximum level of use consistent with good manufacturing practice,
  • (C) tannic acid at a maximum level of use of 200 parts per million, and
  • (D) polyvinylpyrrolidone in an amount that does not exceed 2 parts per million in the finished product,
• (xiii) caramel at a maximum level of use consistent with good manufacturing practice,
• (xiv) brandy, fruit spirit or alcohol derived from the alcoholic fermentation of a food source distilled to not less than 94 per cent alcohol by volume,
• (xv) any of the following substances:
  • (A) carbon dioxide and ozone at a maximum level of use consistent with good manufacturing practice, and
  • (B) oxygen,
• (xvi) sorbic acid or salts thereof, not exceeding 500 parts per million calculated as sorbic acid,
• (xvii) malolactic bacteria from the genera Lactobacillus, Leuconostoc and Pediococcus,
• (xviii) copper sulphate in such a quantity that the content of copper in the finished product shall not exceed 0.0001 per cent,
• (xix) nitrogen, and
• (xx) oak chips and particles

The wine product may be treated with a strongly acid cation exchange resin in the form of sodium ion or a weakly basic anion exchange resin in the form of the hydroxyl ion before the final filtration.

How to Make Red Wine at Home

Short video on how to make red wine at home.

Final Exam Questions

The enzymes in the yeast converts the available sugars in the "must" (grape juice before/during fermentation) to

1. 1. Ethanol and oxygen.
   2. Butyl alcohol and carbon dioxide.
   3. Ethanol and carbon dioxide.
   4. Butyl alcohol and oxygen.
   5. Methanol.

Answer: Ethanol and carbon dioxide.

Which of the following is incorrect to preserve wine?

1. 1. Seal the lid tightly to avoid exposure to oxygen.
   2. Store in a place with large temperature variation to prevent mould growth and contamination of the wine.
   3. Minimize vibration to limit changes in physicochemical properties.
   4. Store in conditions that are dry to limit water activity.

Answer: Store in a place with large temperature variation so that moulds and contamination can't easily grow.

Explanation: Variation in temperature does not prevent the development and growth of moulds nor does it prevent contamination of the wine.

Reflection

Wine is not only delicious, it also contains antioxidants, vitamins, and minerals which promote healthier heart function, help to prevent certain types of diabetes, osteoporosis, cancer, and even tooth decay. Wine is fairly simple to make, and is made from natural ingredients through fermentation. Its production and sales has become a global market, generating millions of dollars through the sales of wines imported and exported internationally. Wine is enjoyed by many all over the world, and has generated a following of wine enthusiasts and wine tasters that attempt to asses the quality and flavor of various types of wine, of which there are many. In addition, rich heavy foods usually go well with red wines, while white wines are commonly recommended with lighter meals, and wines made from sweeter grapes with higher sugar content can be paired with deserts. Lastly, wine ranges widely in flavor, color, region of origin, and price, and is consumed by many for many reasons. With all that being said, our team has gained knowledge in several aspects of wine that we were previously unfamiliar with.

According to our research, the process of its making as mentioned in our video on this Wiki page has shown to be simple and inexpensive. There is no doubt that all alcohol beverages hold intrinsically harmful properties with respect to our health; however, contrary to popular beliefs, the benefits may out weigh the negatives, depending on the amount and the type consumed. Red wine, out of all types alcohol, is one of the healthiest. Its alcohol content is also less than most alcohol beverages. In order for most alcohol beverages to actually damage our health, the amount consumed is the main variable. We must keep in mind that this variable is dependent on the choice of individuals to control, and this holds true for all food types because too much or too little of something is almost always bad.

The more time our group spent researching, investigating, and even making wine, the more appreciation we had to entire production and processing of wine. It requires an incredible amount of precission to produce the perfect grapes during the growing season; patience while the wine is being fermented; and the utmost finesse during the entire process for the best possible flavor. Unlike many other food and drink products out there, a good bottle of wine cannot be manufactured in a factory. With that said, it is no wonder that wine has spawned it's own culture, complete with enthusiasts, magazines, and even retail shops dedicated vinification. However, our most important discovery is wine is one delicious drink.