WSET Diploma D1 Exercises (Specific Options for Red and Rosé Winemaking)

Answer

a) Cold soaking: crushed black grapes are held at a low temperature (about 4–15°C) for several days before fermentation, protected by SO2 and/or carbon dioxide. In water (not alcohol) colour and fruit flavours are extracted with relatively little tannin, so it suits varieties such as Pinot Noir. However, it takes tank time and energy for cooling, and there is a risk of spoilage if the must is not protected.

b) Thermovinification: the must is heated (often to 60–80°C) for a short time, then pressed and the juice is fermented like a white wine. It extracts colour quickly and destroys the oxidative enzyme laccase, which is useful for rotten grapes; but it can give cooked or jammy aromas and wines that are often for early drinking.

c) Flash détente: the grapes are heated quickly (to over 80°C) and then put into a vacuum, which makes the skin cells burst. This gives very fast and high extraction of colour, tannin and flavour and removes some green (pyrazine) aromas; the drawbacks are the high equipment cost and a risk of losing some freshness or typicity.

Grading Criteria

• For explaining what cold soaking is (low temperature before fermentation), you get 1 point.
• For stating that cold soaking extracts colour/flavour with little tannin, you get 1 point.
• For a disadvantage of cold soaking (tank time, cooling cost, spoilage risk), you get 1 point.
• For explaining what thermovinification is (heating the must, then pressing), you get 1 point.
• For stating that thermovinification extracts colour quickly, you get 1 point.
• For explaining that heating destroys laccase, so it is useful for rotten fruit, you get 1 point.
• For a disadvantage of thermovinification (cooked/jammy aromas, wines for early drinking), you get 1 point.
• For explaining what flash détente is (rapid heating, then a vacuum), you get 1 point.
• For stating that flash détente gives very fast/high extraction (or reduces green aromas), you get 1 point.
• For a disadvantage of flash détente (equipment cost, loss of freshness/typicity), you get 1 point.

Answer

a) Punching down (pigeage): the cap is pushed down into the liquid by hand or machine. It is gentle and suits small, open-top vessels (e.g. Pinot Noir), but by hand it is labour-intensive and is difficult in large tanks.

b) Pumping over (remontage): wine is drawn from the bottom of the tank and sprayed over the cap. It is easy to control and suits large tanks, and it can be done with or without air contact; but too much can extract harsh tannins.

c) Rack and return (délestage): the fermenting wine is drained into another tank, so the cap settles, and then it is returned over the cap. It gives thorough, fairly gentle extraction and aerates the wine, and seeds can be removed; it needs a spare tank and more labour.

d) Ganimede® tanks: the carbon dioxide from fermentation collects under a funnel-shaped partition and is released periodically, breaking up and soaking the cap. Extraction is gentle and needs no pumps or extra energy, but the tanks are expensive.

e) Rotary fermenters: horizontal tanks that rotate to mix the skins and the liquid. Extraction is very fast and efficient so fermentation tanks are free sooner, but the equipment is expensive and the wines can lack depth if extraction is too fast.

Grading Criteria

• For explaining punching down, you get 1 point.
• For an advantage or disadvantage of punching down, you get 1 point.
• For explaining pumping over, you get 1 point.
• For an advantage or disadvantage of pumping over, you get 1 point.
• For explaining rack and return, you get 1 point.
• For an advantage or disadvantage of rack and return, you get 1 point.
• For explaining how Ganimede® tanks work (CO2 trapped and released), you get 1 point.
• For an advantage or disadvantage of Ganimede® tanks, you get 1 point.
• For explaining rotary fermenters, you get 1 point.
• For an advantage or disadvantage of rotary fermenters, you get 1 point.

Answer

a) Must concentration: in difficult (wet) vintages, some water can be removed from the must by reverse osmosis, vacuum evaporation or saignée (bleeding off juice). This increases the concentration of sugar, colour, tannin and flavour, but it also concentrates any faults or unripe characters, and it is regulated in many regions.

b) Co-fermentation: fermenting different varieties together (rather than blending later). It is not common for premium Cabernet Sauvignon, which is usually fermented by variety and plot so that the winemaker can decide the final blend later (e.g. Bordeaux). Some producers co-ferment for better integration or colour stability.

c) Post-fermentation maceration: the wine is left on the skins for days or weeks after fermentation. This allows further extraction and polymerisation of tannins, which can make the texture softer and rounder and helps structure for long ageing; but it needs tank space and careful tasting to avoid over-extraction.

Grading Criteria

• For naming a method of must concentration (reverse osmosis, vacuum evaporation, saignée), you get 1 point.
• For explaining when it is used (dilute must in wet vintages), you get 1 point.
• For explaining that it increases concentration of sugar, colour, tannin or flavour, you get 1 point.
• For pointing out a disadvantage (concentrates faults/unripe characters, or is regulated), you get 1 point.
• For explaining what co-fermentation is, you get 1 point.
• For stating that premium Cabernet Sauvignon is usually fermented separately by variety/plot, you get 1 point.
• For explaining that this gives control over the final blend, you get 1 point.
• For explaining what post-fermentation maceration is, you get 1 point.
• For stating that it extracts more tannin or allows tannins to polymerise (softer texture), you get 1 point.
• For a further point (structure for ageing, tank space, risk of over-extraction), you get 1 point.

Answer

In carbonic maceration, whole, uncrushed bunches are placed in a vessel filled with carbon dioxide. Without oxygen, an enzymatic (intracellular) fermentation starts inside each berry, producing a small amount of alcohol (about 2%) and distinctive aroma compounds. The berries then split, are pressed, and the juice finishes fermenting with yeast, usually without skins.

Impact on style: wines are deep in colour but low in tannin, with a soft, fruity style and distinctive aromas of kirsch, banana, bubblegum or cinnamon. Advantages: the wine is ready to drink early, and the method makes high-tannin or high-acid grapes softer (e.g. Gamay in Beaujolais). The wines are usually not for long ageing.

Grading Criteria

• For stating that whole, uncrushed bunches are used, you get 1 point.
• For stating that the vessel is filled with carbon dioxide (no oxygen), you get 1 point.
• For explaining that fermentation starts inside the berries (intracellular), you get 1 point.
• For stating that a small amount of alcohol (about 2%) is produced inside the berries, you get 1 point.
• For explaining that the grapes are then pressed and fermentation is completed by yeast, you get 1 point.
• For stating that the wines have low tannin, you get 1 point.
• For stating that the wines have good colour, you get 1 point.
• For naming typical aromas (kirsch, banana, bubblegum, cinnamon), you get 1 point.
• For stating that the wines are ready to drink early, you get 1 point.
• For giving an example (Beaujolais/Gamay) or noting limited ageing potential, you get 1 point.

Answer

In semi-carbonic maceration, whole bunches are put into a vessel without adding carbon dioxide. The weight of the grapes crushes the berries at the bottom, and the juice released starts a normal yeast fermentation. The carbon dioxide from that fermentation fills the vessel, so the whole berries above undergo intracellular fermentation. After pressing, fermentation is completed.

Impact on style: the wine is a mix of the two styles: it has some of the soft, fruity, low-tannin character of carbonic maceration, with more structure and less obvious ‘carbonic’ aroma. Advantages: it is simpler and cheaper (no need to add CO2) and is widely used in Beaujolais; the proportion of each type of fermentation is harder to control.

Grading Criteria

• For stating that whole bunches are used and no CO2 is added, you get 1 point.
• For explaining that grapes at the bottom are crushed by the weight above, you get 1 point.
• For explaining that this juice starts a normal yeast fermentation, you get 1 point.
• For explaining that CO2 from this fermentation fills the vessel, you get 1 point.
• For explaining that the whole berries above undergo intracellular fermentation, you get 1 point.
• For stating that the grapes are pressed and fermentation is completed, you get 1 point.
• For stating that the wine combines characteristics of carbonic and normal fermentation, you get 1 point.
• For a point about tannin/fruit/aroma (soft, fruity, less obvious carbonic aromas), you get 1 point.
• For an advantage (simpler or cheaper), you get 1 point.
• For an example (Beaujolais) or a disadvantage (less control), you get 1 point.

Answer

a) Direct pressing: black grapes are pressed straight away, so the juice picks up only a little colour during pressing. This gives very pale, delicate rosés (e.g. Provence) with low tannin.

b) Short maceration: crushed black grapes are left with the juice for a short time (a few hours up to about two days) before the juice is drained off and fermented like a white wine. The length of maceration controls the colour and gives deeper, fruitier rosés.

c) Blending: a small amount of red wine is blended with white wine. This is not allowed for still rosé in the EU, but it is permitted for rosé Champagne and in many countries outside the EU. It gives precise colour control.

d) Saignée: some juice is bled off from a tank of red wine must early in maceration and fermented as rosé. This also concentrates the remaining red wine; the rosé is a by-product, so its quality and colour can vary.

Grading Criteria

• For explaining direct pressing, you get 1 point.
• For stating that direct pressing gives very pale, delicate rosés (or an example), you get 1 point.
• For explaining short maceration and the typical length, you get 1 point.
• For stating that the length of maceration controls colour (or that the juice is then fermented like a white), you get 1 point.
• For explaining that blending means adding red wine to white wine, you get 1 point.
• For stating that blending is not permitted for still rosé in the EU, you get 1 point.
• For stating that blending is permitted for rosé Champagne (or outside the EU), you get 1 point.
• For explaining saignée (bleeding off juice from red must), you get 1 point.
• For stating that saignée concentrates the remaining red wine, you get 1 point.
• For noting that saignée rosé is a by-product with variable quality/colour, you get 1 point.