More Information
GLOBAL WINE PRODUCTION
The global production of wine in 2018 was 292 million hectolitres. The major wine producing countries (Italy, France and Spain) all recorded approximately 30% increase in wine production.
World wine production in 2019 in million hectolitres (where 1 hectolitre = 100 litres):
- Italy 54.8
- France 48.6
- Spain 44.4
- USA 23.9
- Argentina 14.5
- Australia 12.9
- Chile 12.9
- Germany 10.3
- South Africa 9.5
- China 9.1
- Portugal 6.1
- Russia 5.5
- Romania 5.1
- Hungary 3.6
- Brazil 3.1
- New Zealand 3
- Rest of the World 29.2
GLOBAL WINE CONSUMPTION
Global wine consumption was at 246 mhl in 2018. USA leads the world in wine consumption, consuming about 33.0 mhl followed by France (26.8 mhl), Italy (22.4 mhl), Germany (20.0mhl) and China (17.6 mhl) make up the top five wine consuming countries. Australia( 6.0mhl) is the 10th largest consumer in the world.
WHAT IS INVOLVED IN WINEMAKING?
Winemaking is an accomplished art and the wine quality depends greatly on the skill of the winemaker. Many winemakers start out as enthusiasts and turn a passion into a living. Good winemakers are always in demand, and great winemakers are highly sought after.
The basic processes of most winemaking can be briefly summarised as follows:
- Removal of unessential material such as stems and leaves
- Grape crushing
- Fermentation
- Storage and Aging, or bottling
The basic difference between red and white wines is that in the production of white wines the grape skins are removed prior to fermentation whereas in the production of red wines the skins are fermented along with the juice. Of course, whilst not nearly as popular, you can make wine from other fruits like elderberries or rosehips, and you can make it using other things like rice. Grapes are ideal for winemaking because they are the only fruits which contain tannins, esters and acids which enable makers to produce stable and consistent wines.
Components of grape juice important for wine production are:
Sgars – glucose, fructose
- Organic acids – tartaric acid, malic acid, citric acid
- Tannins – catechol, chlorogenic acid, caffeic acid
- Amino acids and proteins
- Minerals – phosphates, sulphates
- Vitamins – b-group, ascorbic acid
- Important volatile components that affect flavour and colour
WINEMAKING TERMINOLOGY
Must
This is the fresh-pressed grape juice used to make wine. It is the raw material to which yeast is added and left to ferment.
Tannins
Tannins are a type of polyphenol found in plants. Tannins are found in many types of fruit, including the skin, stem, and seeds of wine grapes. Tannins are also found in the wooden barrels sometimes used to age wine. Most tannic wines are dry and somewhat astringent. Tannins bring a certain complexity and bitterness to wine; wine which is “too tannic” or “overly tannic” is strong and bitter.
The quantity of tannins in wine is dependent on how long the stems, seeds, and skins are soaked with the juice. Longer soaking times mean higher tannin content; this is why red wines contain more tannins than their white counterparts.
Tannins are also antioxidants, which protects wine from oxidation and changes in flavour caused by exposure to air. It should be noted that the taste of tannins softens with age, reducing the “harshness” of the tannic taste over time.
Phenols
These are a diverse group of chemical compounds that affect taste, colour (especially anthocyanins), and even mouth feel in wine. Like tannins, phenol concentrations can be increased through letting the juice “macerate” or sit with the grape skins. Detailed management of phenols may not be necessary for small-scale winemaking; but can be of concern for commercial and high-quality wine production.
Sugar
Sugar is an essential part of winemaking. It drives fermentation, contributes to the taste of the wine, and has an effect how well it ages and is preserved. Winemakers use several terms referring to sugar. The percentage of sugar in the must is the simplest of these measures. Two other measures are also common:
• Degrees Brix (or simply, °Brix) – is essentially the same as ‘degrees balling’ (or °Balling) which is also used in some scenarios. This is a measure of the percentage of sugar at a particular temperature measured using a hydrometer.
• Degrees Baumé – which is approximately half the value of °Brix.
It is also possible to estimate the sugar content of wine via the specific gravity (also known as relative density).
Acidity and De-acidification
Must or wine with a high acid content can be de-acidified with commercially available products. Acidity of the must or wine can be measured by pH. Acidity affects taste. Low levels of acidity result in flat tasting wine. If levels are too high the wine may taste too sharp.
Sulphites
Sulphites are added to wines to stop further fermentation, oxidation and spoilage.
Sulphur dioxide
Sulphur dioxide is an anti-microbial agent which is used as a preservative for musts.
Extract
Wine extract is the solids in a wine. It includes sugar-free extract, minerals and non-volatiles. Extract provides the body and colour to a wine. Water, sugar and alcohol do not form part of the extract.
Filtration Processes
Filtration refers to the removal of undesirable particles in the wine. Various types of filter may be used to achieve this.
Racking
Racking is part of the filtration process. When wine is racked, it is pumped or siphoned off the lees (or sediment) into another vessel. Wine should be racked soon after fermentation because if it remains in contact with the lees for too long it may develop bad flavours. A typical wine would be racked somewhere around two and four times. The removal of the lees ensures greater clarity.
Wines that are finished after the primary fermentation are usually racked quickly. Wines set aside to undergo malolactic fermentation are racked once or twice but not fully, because lees meet the nutritional requirements of the malolactic fermentation bacteria.
The timing of racking depends on the wine’s specific gravity and the density of the lees. In some cases, racking may be required during malolactic fermentation since this type of fermentation may take several months over which time a large quantity of lees may produce bad flavours.
After all fermentation is finished the wine is racked once more. It should be noted that whilst racking is beneficial there is a limit to how often it should be done because each episode allows some oxygen into the system which can accelerate the wine’s ageing.
Fining
A wine which has yet to be racked has a cloudy appearance. This cloudiness is caused by the presence of suspended protein particles. Fining agents are used to get rid of these particles. They are materials which cause proteins to bind together and drop to the bottom of the wine. In doing so, racking and filtration become a lot easier and it also means that fewer racking episodes are needed. Removing these proteins quickly also reduces the likelihood of any bad flavours developing in the wine. Two of the most common fining agents are bentonite and gelatine. There are others available.
Filtering
The final step in finishing a wine before bottling or ageing is filtration. This is done to remove any fine particles. The type of filter used depends on whether or not the wine has been sweetened after fermentation. For unsweetened wines, a particle filter is usually used. This type of filter will remove any remaining suspended particles. If the wine has been sweetened after fermentation, or has any residual sugar, a sterile filter must be used. These are especially fine filters which remove almost all microbes that may be present in the wine (due to its sugar content).
Anything else that comes into contact with the wine must also be sterile so as to maintain a microbe-free state. This includes bottles and corks. The wine must also be transferred straight from filter to bottle to reduce exposure to air. Filtering wine may cause it to taste flat, but this flatness will disappear after several weeks.
TESTING – TASTING – MONITORING
The process of converting grapes into wine can be exceedingly complicated, and the finished product (the wine) can vary significantly in taste, aroma, and visual appearance.
- Aroma refers to what is perceived by smelling the wine
- Taste refers to what is sensed by tasting the wine.
- Visual appearance considers clarity and colour of the liquid.
As the process of making wine progresses, the liquid goes through various changes in it’s chemical and microbiological characteristics, which need to be monitored. Interventions are made along the way to control what is happening, and ultimately the wine which is produced should be relatively stable so that it can be stored until it is drunk, without deterioration in the overall quality.
Discrimination testing
A technique used in sensory analysis to assess if two or more items have a measurable difference. The test uses a group of evaluators (panellists) with a degree of training suitable for the difficulty of the test to distinguish between products through a range of experimental designs, such as:
- Triangle test: A useful multipurpose test where a taster is required to select different samples. This test uses 3 samples two that are identical, and one is different. It has good application in determining if process change affects the overall product characteristic.
- Duo-Trio test: This test is sometimes used instead of a triangle test to compare wines unknown difference. Taters are presented with a reference wine and then two test wines. Evaluators are asked to identify the sample that is same as the reference wine.
- Paired comparison test: It can be used where there is a known difference in the chemical composition of wine. Also, to see if there is a directional difference for a single characteristic.
- Same/Different comparison test: Similar to paired comparison test, however it is used when the difference between two wines is unknown.
Preference testing
Preference testing refers to consumer tests in which the consumer is given a choice to look at one product directly against a second product, as in product improvement studies or when determining parity with a competitive brand. This technique also works very well when the consumer panellists have minimal reading.
For wine studies, consumer evaluations from various perspectives have also been conducted such as studies considering consumer subgroups, clusters, or demographic data, or time-related studies. Many factors must be considered due to the complexity of wine, with the involvement of sensory attributes including intrinsic/extrinsic factors and others such as target consumers and methods.
WHAT CAN GO WRONG IN WINEMAKING
It is essential that people who assess the quality of wine can accurately recognise the common sensory wine faults and taints that occur in wines. Wine faults are defined as off-aromas or tastes that are related to the fermentation or the winemaking process. Wine taints are defined as an odour, taste or aftertaste that originate from external or foreign sources. Some of the common wine faults are as follows:
- Oxidation: Caused when wine is exposed to too much oxygen. Wines that are oxidized will give off aromas that range from dull to cardboard and straw, and stewed fruits.
- Acetaldehyde: Associated with oxidation of ethanol into acetaldehyde. Addition of SO2 during fermentation can increase the concentration of acetaldehyde, as can increases in pH and fermentation temperature.
- Volatile acidity: Occurs when bacteria create acetic acid. Often associated in tanks or barrels with excessive headspace, low SO2 and poor winery hygiene. Affected wines smell of vinegar or acetone, like that of nail polish remover.
- Hydrogen sulphide (H2S): Reduction (by yeast) of elemental sulphur, amino acids etc. into hydrogen sulphide (H2S). It can result in rotten egg, pungent, sulphur like smell; easily detected and dissipates quickly with aeration.
- Dimethyl sulphide: Major compound found in aged wines and formed during wine maturation. The aroma is described like canned corn, cooked cabbage; garlic, burnt rubber.
- Sulphur Dioxide: Excessive addition particularly at bottling. It has sharp, pungent smell.
- Trichloroanisole or Cork Taint: Caused by moulds growing on cork coming into contact with chemicals used in disinfectants. It causes the wine to take on a dank musty and mouldy odour that smells like wet newspaper or cardboard. Avoid bleach, chlorinated solvents and high levels of Cl- in water.
- Geraniol: Normally produced by lactic acid bacteria from sorbic acid. Distinctive geranium odour, floral, sweet, pungent smell. Maintain proper levels of SO2
- 4-Ethyl phenol: Characteristic aroma from Brettanomyces (spoilage yeast). Proper sanitation, maintaining sulphur levels, and eliminating problem barrels is essential. Sterile bottling recommended for problem wines. This compound imparts woody, band aid, medicinal character to wine.
- 4-Ethyl guaiacol: Characteristic aroma from Brettanomyces (spoilage yeast). Wine is described as having Warm, spicy, medicinal, band-aid, pungent, clove/spice aroma.
FAQ
FREQUENTLY ASKED QUESTIONS
Here is a list of the most often asked FAQ’s.
General
Q. Why should I enrol with the Academy for Distance Learning?
A. Here at ADL, our students are our priority – we treat everyone as a unique individual.
Q. Do I need to buy text books?
A. No, as each module has been written by highly qualified industry professionals. The content of the material is presented in such a way that text books are not required. However, if you require additional reading your tutor will be able to supply a list.
Q. What happens if I have to stop studying for a while? (eg. become sick, go on holidays, have a baby, move house, etc)
A. It’s OK to take a break and start up your study at a later point in time. Just let us know.
Q. Is there an age limit?
A. There is no maximum age limit. We do however, have a minimum age limit of 18 years. Below that age parental consent would be required.
Q. Are your courses up-to date?
A. Our courses are revised and updated on a rotation system.
Q. Do you have a Cancellation policy?
A. Yes. We have a cancellation policy that is fair and equitable. For further details please click here.
Q. Will I have any opportunity to engage with other students?
A. We have a Student Community group based on facebook! If you don’t have a facebook account already, you could make one just for talking with fellow students on the group.
Enrolment
Q. When can I enrol/start?
A. You may enrol and start at any time of the year – it’s all self- paced.
Q. Can I study from anywhere in the world?
A. Our courses are available to anyone, anywhere in the world from the comfort of your own home. The course content is relevant to any country, culture or economy.
Q. How long do I have to complete the course?
A. You complete the course at any time that is convenient for you.
Q. Completing a 100 hour module – how long will it take?
A. For some students a 100 hour module will take approximately to 3- 6 months to complete. Others take less time and some even longer.
Assessment
Q. Assessment – how does it work?
A. For each 100 hour module you are assessed by assignments (at the end of each lesson) and a final one and a half hour exam (or you may elect to complete a Project, instead of sitting the exam) – the choice is yours – you sit for the exam in your own location.
Q. I don’t cope well with exams – what can I do?
A. You may elect to undertake a Project (set by your tutor) instead of sitting the exam. Projects are completed from your home and can usually take a couple of weeks to complete.
Q. If my assignment is not up to standard is there an opportunity to resubmit my work?
A. Yes –
Q. How many assignments do I need to complete for each module?
A. At the end of each lesson, there is an assignment – so if a course has say, 10 lessons, there would be 10 assignments.
Q. I am having difficulty attending workshops/industry meetings, what can be done?
A. If your course requires attendance at workshops, conferences, or industry meetings; alternative arrangements can be made in your country.
Qualifications
Q. What qualification will I receive?
A. For individual modules, you would be awarded a Certificate endorsed by TQUK (Training Qualifications, UK), providing you complete all assignments and the exam. If you just want to complete only the assignments and not sit for the exam or finish a Project, then a Letter of Achievement would be awarded. For more details on qualifications available please click here.
Q. Can I customize my diploma/higher qualification?
A. Not all educational institution’s certificates /diplomas meet everyone’s needs. The opportunity to Design Your Own Diploma at the Academy (subject to our approval) is an added bonus, not found at other colleges. You choose modules that you think will help you in achieving your goal.
Q. What do I get when I complete the course? Will I receive a transcript?
A. At the completion of all courses and providing all assignments and exam requirements have been met, you will receive your Award and a Transcript.
Tutors
Q. Our tutors – who are they?
A. We appoint Tutors and require that they must be currently active in their industry, with at least 5 years’ experience in their chosen profession.
Q. Can I contact my tutor at any time?
A. Yes – you have unlimited access to your tutor via email through our Online Classroom. You can always leave a message with ADL requesting your tutor to contact you. You decide on how much or how little contact you wish to have.
Q. Practical work – How is this done?
A. To find out more about this part of the course please visit the section on How Our Courses Work here.
