WSET Diploma practice questions with model answers

Part (a) — Slope, aspect, heat and light 8 marks

• Aspect is the direction a slope faces; slopes that face the sun for most of the day (south-facing in the northern hemisphere, north-facing in the southern hemisphere) receive more solar radiation than those facing the opposite way. [1]
• Their importance increases at high latitudes, where solar radiation strikes the Earth at a low angle, lowest of all in spring and autumn; a slope facing the sun brings that angle nearer perpendicular, increasing the intensity of heat and light reaching the vines. [2]
• As warmth is often the limiting factor at high latitude, this extra heat and light in spring and autumn extends the viable growing season and can decide whether a site is viable, which varieties can ripen and how ripe they become: in Burgundy and Alsace the Grand Cru sites giving riper, more concentrated wines are usually on south-east-facing slopes, while generic appellation vineyards lie on the flat, and the southerly aspect of the hill of Hermitage gives Syrah extra ripeness. [3]
• In warm climates a slope facing away from the sun limits heat and light, allowing earlier-ripening varieties to be grown or wines with less alcohol and more acidity to be made than the latitude would otherwise allow; in Stellenbosch, for example, white varieties are sometimes planted on south-facing slopes so the grapes retain refreshing acidity. [2]

Part (b) — East-facing versus west-facing slopes 6 marks

• East-facing slopes catch the morning sun, which heats the atmosphere when air and soil temperatures are at their lowest, extending the hours of vine growth and grape ripening each day, which is especially valuable in cool climates. [2]
• The canopy, often wet with dew in the morning, also dries earlier on east-facing slopes, reducing the spread of fungal disease and so protecting yields and grape quality. [2]
• West-facing slopes receive the hotter afternoon sun and may become too hot in warm climates, increasing the risk of sunburnt grapes; where there is a coast to the west, as in California and Western Australia, cool afternoon sea breezes can alleviate this. [2]

Part (c) — Further advantages and disadvantages of slopes 6 marks

• Soils on slopes are usually shallower, poorer and better drained than on the valley floor, which limits water and nutrient supply and so vine vigour, an advantage in high-rainfall regions. [2]
• Slopes can shelter vines from wind and rain, and cold air drains down the slope, so frost is less likely to form on the slope itself, protecting young buds and therefore yields. [2]
• However, slopes are prone to soil erosion and surface run-off (which also leaches nutrients), and steep slopes can prevent the use of machinery, making vineyard operations more difficult. [2]

Part (a) — Reasons for falling consumption in traditional wine-drinking countries 12 marks

• Younger people (from legal drinking age to their mid-thirties) are drinking less wine because many regard it as old-fashioned, something their parents or grandparents drank, and turn to other alcoholic drinks instead (gin, for example, is very fashionable among younger drinkers in Spain); the next generation of drinkers is therefore not replacing older wine consumers, so demand shrinks over time. [3]
• In countries such as the UK, younger people also spend less time in bars and contact their friends via social media, removing a social occasion at which wine would have been bought. [1]
• There is growing awareness of the negative health effects of alcohol, particularly among younger drinkers, and government health campaigns reinforce it: the Loi Evin in France, which greatly restricted the advertising of alcoholic drinks, is thought to have contributed to a significant drop in French wine consumption. [3]
• Busy, modern lifestyles leave less time for the longer meals at which wine was traditionally drunk, and in countries with a tradition of drinking wine at lunchtime, alcohol during the working day is increasingly forbidden by employers or no longer socially acceptable, so two traditional consumption occasions are disappearing. [2]
• Traditional producing countries once produced, sold and consumed large volumes of inexpensive wine locally; measures to reduce over-production, such as vine pull schemes, have cut the volume of this cheap wine, and instead of trading up to more expensive wine some consumers have switched to other, cheaper alcoholic or non-alcoholic drinks, so the lost volume is not recaptured by wine. [3]

Part (b) — Reasons for growth in the USA and China 8 marks

• Over the last 20–30 years wine drinking has become part of mainstream culture in the USA, which overtook France and Italy to become the world's largest wine-consuming country. [1]
• This has been helped by the globalisation of the food and drinks industry: the growth of multinational corporations, the increased ability of companies to export across national borders and consumers more able and willing to embrace new tastes have made wine widely available and accepted. [2]
• Both increases and improvements in domestic US wine production have supplied wines that American consumers want to buy, supporting the growth in consumption. [1]
• China has a growing middle class, and one way this group shows its improved wealth and status is by moving from local drinks to wine, so rising incomes translate directly into rising wine demand. [2]
• Many middle-class Chinese consumers aspire to drink imported wine; at first they chose mainly French wines, but they increasingly look to countries such as Australia and Chile, whose wines benefit from a bilateral trade agreement that makes them more competitively priced. [2]

Part (a) — How the climate produces outstanding wines in the best years 8 marks

• Bordeaux has a moderate maritime climate in south-west France close to the Atlantic; the warm Gulf Stream, originating in the Gulf of Mexico, is a warming influence that allows late-ripening Cabernet Sauvignon to reach full ripeness on the Left Bank. [2]
• In the best years there is warmth throughout the growing season, plentiful rainfall to promote growth and ripening, and a relatively dry, warm first month of autumn, which together allow steady and complete ripening of the grapes. [2]
• This slow, complete ripening produces an excellent balance of tannins, sugar and acidity, which partly explains the remarkable longevity of great Bordeaux vintages. [2]
• The Gironde estuary moderates temperatures for the vineyards adjacent to it, which is why the most prestigious Médoc estates lie close to the estuary and are often spared the frost that hits vineyards a short distance to the west. [1]
• The Landes pine forests partially protect the Left Bank from Atlantic storms, although estates fringing the forest (Domaine de Chevalier in Léognan, many in Listrac) are cooler and more marginal than their neighbours to the east. [1]

Part (b) — Weather hazards and their effects on quality and volume 12 marks

• Rainfall averages 950 mm a year but varies markedly from year to year and in when it falls; excessive rain at key moments in the season is the most important cause of vintage variation in Bordeaux. [2]
• Rain at flowering causes poor fruit set and so reduces the crop; Merlot, the most planted variety, is particularly susceptible to coulure. [1]
• Rain throughout the growing season raises pressure from downy mildew, powdery mildew and botrytis bunch rot; when a mildew attack is followed by rain, tractors cannot enter the vineyard to spray and the rain washes away treatments, compounding the problem. [2]
• Rain at and after véraison leads to unripe fruit and fungal disease, while rain at harvest dilutes flavours; this is why mid-ripening Merlot, which can be picked before early autumn rain, has been favoured over late-ripening Cabernet Sauvignon in wetter sites and years. [1]
• Spring frost periodically devastates large areas, as in 1956, 1991 and 2017; in frost-affected 2017, 33 per cent less wine was made than the ten-year average and 40 per cent less than in the large 2016 harvest, a swing in volume with serious financial consequences for estates and for the regional wine business as a whole. [3]
• Hail has always been sporadic in Bordeaux but has become more widespread and destructive over the past decade. [1]
• Climate change has brought hot, dry summers with insufficient rainfall: years such as 2003 give red and white wines with low acidity that lack balance, and alcohol levels have risen as growers wait for phenolic ripeness; well-drained gravel and shallow soils (Pomerol soils are rarely more than a metre deep) can leave vines suffering drought stress, as seen in the very dry summer of 2016. [2]

Part (a) — Comparison of production processes 10 marks

• Second fermentation: in the traditional method it takes place in the bottle in which the wine is sold, after adding liqueur de tirage (wine and/or must, sugar, cultured yeast, nutrients and a clarifying agent such as bentonite and/or alginate to aid riddling), whereas in the tank method sugar and yeast are added to the base wine in pressurised (reinforced) tanks, so large volumes ferment together. [2]
• Yeast and first fermentation: autolytic traditional method styles use a neutral yeast so that primary aromas do not compete with autolysis, whereas fruit-based tank method wines may benefit from strains that promote thiols or esters and are fermented at 16–18°C to retain fresh floral and fruit aromas. [2]
• Control of fermentation: in bottle, stored sur latte at a constant 10–12°C, fermentation typically lasts 4–6 weeks and runs to dryness, 24 g/L of sucrose giving about six atmospheres; in tank it is rapid and is arrested by chilling to 2–4°C once the desired pressure and residual sugar are reached, so the wine may spend as little as one month in tank. [2]
• Lees contact: traditional method wines normally age on the lees in bottle (a minimum of nine months for Cava, more typically 15–18 months), whereas tank method wines are usually removed from the lees immediately. Lees ageing in tank (e.g. nine months at 2–4°C with paddles stirring the lees) is possible but ties up expensive pressurised tanks, losing much of the method's economic advantage. [2]
• Removing the yeast: the traditional method requires riddling (up to eight weeks by hand in pupitres or three to four days in gyropalettes), disgorgement of a frozen plug and the addition of liqueur d'expédition; tank method wine is instead cold stabilised, the yeast removed by centrifugation or filtration, sugar and SO2 adjusted, then sterile filtered, chilled to –2°C and bottled with a counter-pressure filler. [2]

Part (b) — Comparison of style, quality and price 10 marks

• Flavour: traditional method wines aged on the lees develop biscuit, toast and brioche notes from autolysis, and after disgorgement the dosage reacts with autolytic compounds (the Maillard reaction) to give roasted, toasty aromas; the tank method, by contrast, preserves the grapes' primary aromas, making it the preferred method for semi-aromatic Glera (Prosecco) or aromatic Muscat and producing fresh, fruity, floral wines. [3]
• Mousse: tank method wines not aged on the lees tend to have lively but short-lived bubbles, whereas traditional method wines aged on the lees for 18 months or more have a longer-lasting foam. [2]
• Cost and price: the tank method makes large volumes inexpensively and quickly, with significantly lower labour costs because there is no riddling, no disgorgement and typically no long lees ageing, so wines can be released for sale quickly at lower prices; in the traditional method bottle handling, riddling, disgorgement and stock tied up on the lees all add cost that must be recovered in a higher price. [3]
• Quality perception: the tank method is often seen as inferior, partly because of the prestige of the traditional method, especially Champagne, and partly because, as an inexpensive method, it is often used with lower-quality grapes; yet for aromatic varieties it is a deliberate stylistic choice rather than simply a cost saving. [2]

Part (a) — Conditions for flor 7 marks

• Flor is made up of four strains of Saccharomyces cerevisiae, present on grape skins in Jerez and in the bodegas, and forms naturally on the surface of young wine under the right conditions. [1]
• The wine must be no more than 15.5% abv (flor struggles above 16% abv), hence fortification to 15–15.5% abv, and SO2 must not be added, as it would inhibit flor. [2]
• Flor needs plentiful oxygen, so butts are filled only 85–90% and bungs are loosely inserted, keeping air in the headspace. [1]
• Temperatures of 16–20°C and humidity above 65% are needed. Bodegas achieve this without air conditioning: thick walls steady temperature; high ceilings let warm air rise above butts stacked only three or four high; small high windows face cool, damp south-westerly Atlantic winds; earth floors are wetted in summer to cool the air and raise humidity. [3]

Part (b) — Effects of flor on the wine 7 marks

• The film protects the wine from oxidation, so it remains pale lemon. [1]
• Flor consumes alcohol and releases acetaldehyde, giving aromas of apple skin or bruised apple, hay and chamomile and sometimes a slightly bitter taste. [2]
• It consumes glycerol, giving a lighter body; as glycerol tastes slightly sweet, its loss adds to the very dry palate. Flor also reduces acetic acid. [2]
• Dead yeast cells fall to the bottom of the barrel and undergo autolysis, adding savoury, nutty flavours and texture. The balance of the four strains varies by area, bodega and solera stage, changing how much alcohol is consumed and acetaldehyde produced. [2]

Part (c) — The solera system 6 marks

• Barrels are grouped into criaderas of the same age; the oldest is the solera, followed by the 1st, 2nd and further criaderas. No more than 40% of a system can be removed each year, and wine must be at least two years old to be sold. [2]
• Wine drawn from the solera is replaced by wine from the 1st criadera, blended in tank for consistency, and so on up the system, with the youngest criadera refilled from the sobretablas. [1]
• Young wine is rich in flor nutrients (alcohol, glycerol, acetic acid) that are used up during ageing, so refreshing older wine keeps a thick flor alive and protecting it. Fino and Manzanilla systems therefore release smaller volumes more often, so the wine reaches the consumer fresher, important because it does not improve in bottle. [3]