Aim: The aim of this organic chemistry activity was to produce one bottle, 750ml, of high quality wine made from the controlled fermentation of marulas from the Marula tree. Name of wine: The name of the wine is Maruvalous. This name came from the combination of the two words marvellous and marulas. The word marvellous was thought of as it is similar to the word marula and it fits in with the aim which is to make a high quality bottle of wine.
Chemical Process of Fermentation:
Fermentation refers to an anaerobic process when micro-organisms break down large organic molecules into simpler molecules. Most familiar type of fermentation is known as alcoholic or ethanolic fermentation and is when sugars and starches are converted to alcohol by the enzymes in yeast. The starch is converted into sucrose and glucose which are simple sugars. These simple sugars are then converted to alcohol (ethyl alcohol) and carbon dioxide. (Science Clarified, 2010).
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Alcohol fermentation is done by bacteria and yeast. (Freeman, W,H. ) These are the microorganisms which convert the simple sugars into carbon dioxide and ethyl alcohol. The fermentation process of alcohol begins after the glucose enters the cell. Under anaerobic conditions the microorganism converts the glucose into pyruvic acid via glycolysis, which means dissolution of sugar. The six-carbon glucose is broken down into two molecules of three-carbon organic acid, pyrvic acid and a transfer of chemical energy to ATP. (Britannica Encyclopedia, 2010) Carbon dioxide, ethanol and energy are converted from the pyruvic acid. The microorganism most commonly used is yeast. Yeast, Saccharomyces Cerevisae, (Tempeh Info) is unicellular fungi which reproduce asexually through binary fission. The fermentation reaction may be shown as:
Yeast+ Glucose ïƒ Alcohol (ethanol) + Carbon dioxide (Wong, G. 2003)
This natural fermentation can give wines an alcohol percentage of up to 16%. After the initial fermentation of the wine, the liquid ferments for a further twenty days to a month. This second fermentation allows for the dead yeast cells and other particulate matter to settle at the bottom. The carbon dioxide is released from the wine into the air leaving behind the wine. Once this fermentation stage is over, the sediment is removed from the wine. The wine then moves to an aging tank where the aging process continues and yet again the sediment will be removed. This is known as racking. (Wong, G. 2003)
Wine makers will often add more nitrogen and micro nutrients during the fermentation process to prevent a chemical reaction in which the gas, sulphide, is released. Sulphide gives the wine a rotten smell and therefore ruins it. (Virtual Wine. 2005)
The second phase of the wine fermentation process is when the wine is tapped off into a container which is airtight and precaution is used not to add any more unnecessary oxygen. This phase of the fermentation process produces higher alcohol content. (Virtual Wine, 2005)
Ethanol: Alcohol that is the metabolic product of yeast in wine and beer making. It is produced by yeast during fermentation.
Method of making marula wine
DAY 1 - SUNDAY
A black bag filled with marulas was picked from Matumi Golf Estate. The ripest marulas from the bag were chosen and used which were the yellow ones.
The yellow marulas were rinsed and cleaned. A bucket of water was filled and the marulas were put in it to see if any of them floated. Those that were floating were thrown out for being rotten.
The marulas were sliced and the skins were peeled off.
The peeled marulas (still containing the pips) were all weighed on a scale and added to the container holding the fruits.
From the skins that had been peeled off the marulas, a spoon was used to scrape off the left over marula pulp so that no juice was wasted.
The scraped off pulp was added to the container after it too had been weighed.
Overall around 3kgs- 4.5kgs of marula pulp had been weighed and put into the container.
The kettle was boiled and the container was filled up with the boiling water to the height that the marulas reached.
Camdon Sterilizing tablets were added to the container.
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The container was closed.
The container was left for 20 hours in a storeroom at room temperature to ferment. Temperature was controlled as the door to the storeroom was kept closed. It was around 250C.
DAY 2 - MONDAY
The pips were removed from the mixture so that only the water and pulp remained.
4 hours later, 2 teaspoons of pectolase was added.
DAY 3 - TUESDAY
The juice from the container was strained through a fine sieve.
The following ingredients were added:
Sugar(750g white, 300g brown ) , yeast(1 tsp), citric acid(1 tsp), tannin(1/4 tsp), yeast nutrient (1 tsp). No extra yeast was added, one teaspoon was put in as prescribed.
The mixture was stirred well and it was placed in a new closed container which had a small opening to let some gases escape.
DAY 10 - TUESDAY
The wine was strained further
The percentage of alcohol was measured with a hydrometer. The reading showed a reading of 10%.
2,5 litres wine had been made and was in the container.
The wine was tasted to check that it had not turned to vinegar and to see if it was on the right path to becoming high quality.
The wine, still in the container, was left to stand and settle.
DAY 12 - THURSDAY
The wine was strained for the final time and placed in the fridge to stop the fermentation process.
Diagram of set up apparatus:
sterilizing tablets (Camdon)
Large plastic sealable containers (one container for one wine) (at least 5 litres)
5 Litre container (no lid necessary)
Muslin cloth for straining
Label of Maruvalous Wine:
THE WILD GOLDEN FRUIT OF AFRICA
In the heart of the Lowveld Estate lies the lingering sensation of sweet marulas.
All marulas were handpicked at optimum ripeness and are of the highest quality.
For maximum enjoyment compliment the wine with cheese, crackers and fish dishes.
Alc. 10% 750ml
PO Box 16058
Republic of South Africa
Not for sale to persons under the age of 18.
Analysis of results:
Colour: The wine had a smooth and distinct colour. The colour was a light yellowish to clear murky. It looked appealing yet it lacked intense attractiveness which left it to achieve a 6 in colour.
Clarity: The wine had no sediments in it yet it wasn't completely clear. It seemed to have a slight murkiness to it. Finer straining of wine would've allowed for better clarity.
Bouquet: The least mark achieved for this. The wine smelt like wine, it was pleasant but perhaps a bit too strong due to the high alcohol concentration. The sensation of the wine was strong but not to the point where it was unbearable. It was definitely not vinegar! It may have fermented for a bit too long.
Taste: The taste was pleasant and defined and definitely tasted like a wine and not vinegar. The taste was, however, very strong because of high alcohol content. Although the taste was strong the wine was complimented by many of the tasters. It had a very distinct and smooth taste.
Presentation: A good presentation score of 6 was achieved. Many decorations were used and a themed colour of gold was used throughout the display. Glass was used all over the display, one glass jar was filled with ripening marulas and a glass ice bucket was used to keep the wine being tasted cool. Each member had a name tag which had on their name and "Lowveld Estate" which was the made-up company name. Each member also had an arm serviette which added to the professionalism and emphasised the high quality of the Maruvalous wine. Appealing labels were made for the actual bottle and the back label help information. The wine was corked by the members and sealed by a waxy coat. This, however, was not explained during the presentation and so much of the effort went by unnoticed which could've been responsible for the lost marks.
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General analysis: on the first wine tasting on day 10, the wine tasted really good. It should've been decided to stop the fermentation process then because the extra two days allowed for the wine to strengthen quite a lot more. If this had been done, higher marks would have been achieved as the wine would have as strong and therefore tasted better. Many methods had been researched and the chosen one proved to be very successful. The method was simple which allowed for fewer errors. Originally, the uniformed choice was made to pick green marulas. The yellow ones proved to be easier and worked a lot better in terms of taste and for quicker fermentation. Time was wasted because of this first error.
A high quality wine was definitely made. The overall score was very high as the results obtained were very good. Certain areas of the process could have been improved yet the method proved to be very effective. The overall the aim was achieved resulting in Maruvalous coming tie for first place.
Uses of Alcohol in Society
There are many important uses of the simple alcohols such as ethanol, methanol and propan-2-ol. (Clark, J. 2003) Alcohol in alcoholic drinks such as beer, wine or liquor is ethanol and is known worldwide for getting people intoxicated.
Ethanol is used in a variety of products. The most popular use is that in the automotive fuel industry. There are cars which run entirely on ethanol or fuel mixtures containing ethanol and petrol, known as Gasohol. (Clark, J. 2003) Ethanol gives off carbon dioxide and water when it burns which is how it may be used as a fuel itself. For countries without oil industries, ethanol is a useful way for them to reduce import costs because ethanol can be produced by fermentation.
Ethanol is commonly used as a solvent as it can be used to dissolve many different organic compounds which would normally be insoluble in water. This shows that ethyl is a relatively safe alcohol and is used in many cosmetics and perfumes. In the presence of an acid catalyst ethanol will make an ethyl ester. The two most used esters of ethyl are ethyl acrylate and ethyl acetate. (Cartella, J.) These two esters make up many products such as coatings, paints, adhesives and nail polish remover.
It is also used in the production of house detergents. Ethanol has the ability to denature bacteria and is therefore a good disinfectant and used in many instances for sterilization. Ethanol is also sold as methylated spirits. (Clark, J. 2003) This is ethanol and a small amount of methanol combined, however, methanol is toxic which makes it unfit to drink.
Medically, ethanol is used often and carries importance. Ethanol is used to concentrate the medicinally active compounds which make the medication easier to distribute as well as improving its absorption. (Brinker, F.) Dehydrated form of alcohol may also be injected in close proximity to nerves to relieve long term pain. (McGraw) An epidural, which many women receive during pregnancy, is an injection of ethanol to help with the pain. Injections of ethanol may destroy sympathetic ganglia (swelling, lumps, cysts and tumours) and help produce vasodilatation, pain relief and assist in healing wounds.
However, the consumption of alcohol is one of the greatest uses. (O'Leary, D. 2000) A variety of alcoholic beverages, made with ethanol, can be produced through the fermentation process. Wine is a very well known alcoholic drink made from the fermentation of grapes. Grapes are not the only fruit used but are the most popular. Mead is wine made from honey and Sake is wine made in Japan from rice. (Science Clarified, 2010) It has been said that in ancient times wine made from grapes was given to the men by the god of wine, Bacchus. In present times, red wine plays a vital role in Holy Communion. It is drunk by Christians in remembrance of the blood shed by Jesus Christ who died on the cross for us. (Feather, 2007)
Abuse of alcohol in Society
Alcohol abuse in today's society is a huge factor. Those who abuse alcohol do not only affect themselves but they affect all those around them. (Sohail, K. 2007/10/03) Excessive drinking is detrimental to one's health. (How to Advice. 2010) Recent studies have been giving shocking reports of the abuse in today's society. There are a number of health problems that are all emerging from alcohol abuse. Many of the societal problems faced today such as spouse abuse, child abuse and dysfunctional family relationships can be traced back to drinking.
Alcohol can lead to liver damage, cancer, osteoporosis and depression. (How to Advice. 2010) The studies show that women, however, are more susceptible to these effects than men. Social drinking is taken too far in many cases and college students sometimes don't know where to stop.
In the past few years it has become cool for college students to drink excessive alcohol and then post the drunken pictures of themselves on facebook or my space. (Morgan, K.L. 2008) Other young kids see this and they too then think it's cool and they go out and do the same. These students do not realise that they are putting their reputations at stake. Many employers have grown wise to facebook and will look up their applicant. There are also the occasional girls who get drunk and place nude pictures of themselves on facebook. Many cases of rape and sexual assault have resulted from this action.
More than half of the accidents and suicides are a result of alcohol abuse. A study done in an emergency room in the United States gave the results that more than one drink doubled the risk of injury and more than four drinks increased that risk eleven times. (Sita Gita, Alcoholics Anonymous. 2000-2009.)
In families with members suffering from alcohol abuse, the children tend to do a lot worse academically and have a higher risk of suffering from depression, anxiety, stress and a lower self esteem. (Sita Gita, Alcoholics Anonymous. 2000-2009) These households are less cohesive, have more conflicts, and are less independent and expressive. Children and spouses are often abused but even if they aren't they still suffer emotionally. The family is also subjected to financial burden which may lead to stealing and eventually remove them from their comfortable lifestyles. There is an inherited risk for alcoholism. Scientists have recently identified a gene that appears to make those who have it more likely to become addicted to alcohol. (Morgan, K.L. 2008) It was found that children from alcoholic families suffer long term as these adult children are at higher risk for divorce and psychiatric symptoms.
Economically, alcoholism is a multi-billion dollar disease. (Shaw, J. 2009/24/10) The country loses a lot of money as there is the loss of employment, loss of earnings which therefore reduces productivity and there is an increased cost for treatment and hospitalisation. There are many vehicle collisions, increase in crime, property loss and damage and social welfare programs take a huge toll in money.
Health care costs are huge. Alcohol related car accidents are the number one death toll for teenagers. (Shaw, J. 2009/24/10) This is because alcohol is most frequently used by the teenagers and has the most negative health consequences. Heavy drinkers have higher health care costs than those who drink moderately. This all negatively affects the economy as whole because people have become less responsible with alcohol usage in the past few years. This is said to be due to the increased advertising from older teenagers and younger adults.