Section 2 · Factors Affecting the Style, Quality and Price of Wine

Red and Rosé Winemaking

Red winemaking is more involved than white because the grapes must be fermented on their skins to extract both colour and tannin. This chapter covers how winemakers control that extraction, from the moment the grapes are crushed through fermentation, maceration, pressing, and maturation, and how those decisions create everything from light, fruity Beaujolais to dense, age-worthy Barossa Shiraz. It also covers the distinct methods for making rosé.

Aroma kit focus: red cherry, black plum, raspberry, strawberry, vanilla, clove, black pepper, leather

Why Skin Contact Is Essential for Red Wine

The juice inside almost all wine grapes, whether red or white varieties, is pale and nearly colourless. The deep colour of red wine comes entirely from pigments (anthocyanins) in the grape skins. Tannins also come primarily from the skins, along with seeds and stems.

For this reason, red winemaking requires the juice to remain in contact with the skins during fermentation. The alcohol produced during fermentation acts as a solvent, extracting colour, tannin, and flavour compounds from the skins into the juice. This is the opposite of white winemaking, where the juice is separated from the skins before fermentation.

The key parts of the grape for red winemaking:
  • Skins: contain anthocyanins (colour), tannins, and flavour compounds. The primary source of extraction.
  • Seeds: contain harsh, bitter tannins. Winemakers generally try to avoid excessive seed tannin extraction.
  • Pulp: contains sugar (which becomes alcohol), water, and acids. This is the bulk of the grape.
  • Stems: contain aggressive, green tannins. Most winemakers remove the stems (destemming) before fermentation, though some leave a proportion in for structure.

The Red Winemaking Process: Step by Step

1. Crushing and Destemming

Red grapes arrive at the winery and are typically destemmed (stems removed) and crushed (skins broken open to release the juice). The order can vary, some machines destem first, others crush first, but the result is a mixture of juice, skins, seeds, and pulp called must.

Whole bunches: Some winemakers choose to include a proportion of whole bunches (with stems) in the fermentation. This is traditional in Burgundy and parts of the Rhône. It adds a savoury, spicy character and can contribute a firmer, more structured tannin profile. However, the stems must be fully ripe (lignified); green stems add harsh, bitter flavours.

2. Pre-Fermentation Maceration (Cold Soak)

Some winemakers choose to leave the crushed grapes at a low temperature (below 10°C / 50°F) for several days before allowing fermentation to start. This is called a cold soak or cold maceration.

Purpose: At low temperatures, alcohol has not yet been produced, so the extraction is gentler. Colour (anthocyanins) dissolves readily in water, so colour is extracted during cold soak. Tannins are more soluble in alcohol, so they are not readily extracted at this stage. The result is that cold soaking can extract colour and flavour compounds without extracting harsh tannins.

When it's used: More widely than people assume. It is standard practice for much Pinot Noir, where the winemaker wants colour and flavour without harsh tannin, but the textbook also describes it as common for Cabernet Sauvignon and Grenache. Not all producers use it, it is a stylistic choice.

3. Fermentation

Red wine fermentation temperatures typically range between 20°C and 32°C (68°F and 90°F), significantly higher than white wine fermentation. These higher temperatures are necessary to aid extraction of colour, flavour, and tannin from the skins.

Temperature effects:

  • Lower end (20–25°C): slower, gentler extraction. Preserves more primary fruit character. Used for lighter, fruitier styles.
  • Higher end (28–32°C): faster, more aggressive extraction of colour and tannin. Encourages development of more complex flavours. Used for full-bodied, structured styles meant for ageing.
  • Too hot (above 35°C / 95°F): dangerous. Can kill the yeast and cause a stuck fermentation.

Temperature control during fermentation allows the winemaker to influence the amount of colour, flavour, and tannin extracted. For example, although tannins become more soluble as alcohol levels rise, a winemaker can reduce tannin extraction by lowering the temperature towards the end of fermentation. Varieties differ: Cabernet Sauvignon is usually fermented at 26–30°C with gentle handling late on, while Pinot Noir fermentations often climb above 30°C.

Fermentation Vessels

Red wines can be fermented in stainless steel tanks (most common), concrete vats, or oak vessels. Large, open-top vessels are traditional in many regions because they make it easy to manage the cap (see below). Stainless steel offers precise temperature control and hygiene. Barrel fermentation, common for whites, is impractical for reds because you cannot work the skins inside a barrel.

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Exam Angle

Understand the relationship between temperature → extraction → style. Higher fermentation temperatures = more extraction = more colour, tannin, and body = fuller, more structured wine. Lower temperatures = less extraction = lighter, fruitier wine. This cause-and-effect reasoning scores well in short answers.

Cap Management

During red wine fermentation, CO₂ produced by the yeast pushes the grape skins to the surface, forming a thick mass called the cap. If left alone, the cap sits on top of the liquid and very little extraction occurs. The cap also becomes a breeding ground for bacteria if not kept moist. Winemakers must regularly break up or submerge the cap to maintain contact between the skins and the juice. The method and frequency of cap management is one of the most important decisions in red winemaking.

Punching Down (Pigeage)

The cap is pushed down into the juice from above, traditionally by hand with paddles or by foot. Today, mechanical paddles often achieve the same effect, and for a good reason beyond labour: a fermenting vat gives off carbon dioxide, and workers leaning over an open vat to punch down by hand risked being overcome by it.

Character: This is a relatively gentle technique and is very effective at extracting colour and tannin. Winemakers need to take care not to punch down too vigorously or too often. This is particularly important at the end of fermentation when tannins are more easily extracted, if too much tannin is extracted, the finished wine can taste overly bitter and astringent.

Where it's common: Burgundy (Pinot Noir), where gentleness is key; also used for many premium wines worldwide.

Pumping Over (Remontage)

Juice is drawn off from the bottom of the fermentation vessel and pumped over the top of the cap, soaking it. This is a more vigorous technique than punching down.

Character: Good for extracting colour and flavour. Can be more aggressive than pigeage, and is a popular, widely used extraction technique. It also cools the must (the juice loses heat on its way round) and gives the yeast a dose of oxygen. The level of extraction can be controlled by adjusting the volume pumped and the frequency.

Where it's common: Bordeaux and most large-scale red wine production worldwide.

Rack and Return (Délestage)

The entire volume of juice is drained from the fermentation vessel into another tank, leaving the cap behind. The juice is then pumped back over the cap. This is normally only used once or twice during a fermentation, as it can be very extractive.

Character: Aggressive extraction. A good way of dissipating heat and aerating the must. Also helps separate seeds from the cap (seeds sink when the juice is drained, and can be removed to avoid harsh seed tannin).

Rotary Fermenters

Fermentation takes place in rotating horizontal tanks. The entire vessel rotates, keeping the juice in constant contact with the skins. This is efficient and allows continuous extraction without manual labour.

Character: Very efficient extraction, but can be aggressive. Used mainly for large-volume, commercial wine production where consistency and efficiency are priorities. Not common for premium wines due to the risk of over-extraction.

The extraction equation: The level of extraction is controlled by three variables: (1) the technique used (punching down is gentler than rack and return), (2) the duration and frequency of cap management, and (3) the temperature of the fermentation. The winemaker adjusts all three to achieve the desired style.

Maceration Timing and Pressing

Total Maceration Time

Maceration refers to the total time the juice is in contact with the skins. This can range from as little as a few days (for light, fruity reds) to several weeks or even months (for deeply extracted, age-worthy wines).

Maceration Duration and Style
Short (5–8 days)
Light colour, soft tannin, fruity character. Typical for Beaujolais, young-drinking reds, basic commercial wines.
Medium (10–18 days)
Good colour, moderate tannin, balance of fruit and structure. The sweet spot for most mid-range reds.
Long (3–4+ weeks)
Deep colour, firm tannin, concentrated flavour, built for ageing. Top Bordeaux, Barossa Shiraz, Napa Cabernet Sauvignon.

Post-Fermentation Maceration (Extended Maceration)

After alcoholic fermentation is complete, some winemakers choose to leave the wine in contact with the skins for an additional period. This post-fermentation maceration (also called extended maceration) can last from a few days to several weeks.

Purpose: Further extraction of tannin, which is not always wanted. Where it is, the tannins extracted during this phase tend to be softer and more polymerised than those extracted during fermentation, and some winemakers run very long macerations for exactly that smoother, more velvety structure.

Risk: If the skins stay in contact for too long, harsh, astringent compounds can be extracted. The winemaker must taste regularly and decide when to press.

Pressing

In red winemaking, pressing happens after fermentation (the opposite of white winemaking). The wine is drained off the skins (this is the free-run wine), and then the remaining skins and seeds are pressed to extract additional wine (the press wine).

Free-run wine is lighter, softer, and more elegant. Press wine is deeper in colour, higher in tannin, and more concentrated, and it changes as the press tightens: the first fraction is close to free-run, the later fractions progressively darker and more tannic. The winemaker will typically keep these separate and blend them later in whatever proportion achieves the desired style, using the later fractions to adjust colour and tannin.

Many premium producers use the press wine to add structure and colour to the final blend, while entry-level wines may use mostly free-run wine for a softer, more approachable style.

Malolactic Conversion and Maturation

Malolactic Conversion in Red Wines

Unlike in white winemaking, where MLF is optional, virtually all red wines undergo malolactic conversion. This is considered standard practice, not a stylistic choice. The reasons are:

One difference from whites: reds rarely gain anything from extended lees contact. They have been through MLC and have enough tannin and body already, so lees work is a white-wine tool.

Maturation Options

After fermentation and MLF, the winemaker chooses how to mature the wine before bottling. This decision has a major impact on the final style and price.

Oak Barrels

Oak is the most important maturation vessel for premium red wines. It contributes:

  • Flavour compounds: vanilla (from vanillin in the wood), toast, spice (clove, cinnamon), cedar, coconut, smoke. The specific flavours depend on the type of oak, level of toasting, and whether the barrel is new.
  • Tannin: oak tannins add structure and contribute to the wine's ageing potential. Oak tannins are typically finer and smoother than grape tannins.
  • Micro-oxygenation: the small amount of oxygen that passes through the wood softens the wine over time, helping tannins polymerise (join together) into longer, smoother chains that feel less aggressive on the palate.

French vs American oak: French oak (the most prestigious and expensive) contributes more subtle, spicy, cedary flavours. American oak is more assertive, contributing stronger vanilla, coconut, and sweet spice notes. French oak barrels cost roughly twice as much as American.

New vs old: New oak barrels contribute the most flavour. After three or four uses, a barrel is essentially flavour-neutral and only provides the benefit of micro-oxygenation. Top Bordeaux châteaux may use 50–100% new oak; mid-range wines use a mix of new and old. The clear trend, which the textbook flags, is away from maturing premium reds entirely in small new barriques: more older barrels, larger vessels, and a lighter touch.

Duration: Ranges from 6 months (light reds) to 24+ months (top Bordeaux, Barolo, Gran Reserva Rioja). Longer ageing means more oak influence and more softening from micro-oxygenation, but also higher cost (the wine ties up barrel space and capital).

Large Old Oak Vessels

Traditional large casks (called botti in Italy, foudres in France, fuders in Germany) are flavour-neutral because of their size and age. They allow very slow micro-oxygenation without adding oak flavour. Traditional in Barolo/Barbaresco (Piedmont), Alsace, and parts of the Rhône.

This style of maturation emphasises terroir and fruit character rather than oak flavour.

Stainless Steel or Concrete (No Oak)

Wines matured in inert vessels retain pure fruit character with no oak influence. This approach is used for wines designed to be drunk young and fresh, where the emphasis is on primary fruit flavour and soft tannins.

Examples: Beaujolais, basic côtes du Rhône, many entry-level varietal wines worldwide.

Oak Alternatives

Oak staves, chips, or shavings added to stainless steel tanks. A much cheaper alternative to barrel ageing. The flavour is coarser and less integrated, but it provides an oak character for wines at lower price points. Not permitted for many European PDO wines.

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Exam Tip

When the exam asks about the role of oak, remember the three contributions: flavour (vanilla, toast, spice), tannin (additional structure), and texture (softening through micro-oxygenation). Also note that new oak adds flavour while old oak does not, this distinction comes up frequently.

Whole-Bunch Fermentation: Carbonic, Semi-Carbonic and Mixed

Everything above assumes crushed fruit, which is how the vast majority of red wine is made. The textbook treats whole-bunch fermentation as a separate family with three forms. All three rely on intracellular fermentation, a fermentation that starts inside the intact berry without yeast and produces distinctive fruity aromas, and all three need fully ripe stems, since green stems taste bitter. The first two produce light, fruity, aromatic wines with very soft tannins; the third is used to add brightness and silk to otherwise conventional premium reds.

Carbonic Maceration

Whole, uncrushed bunches of grapes are placed in a sealed vessel filled with CO₂ to remove all oxygen. This creates an oxygen-free environment where an intracellular fermentation occurs inside each berry, the berries ferment from the inside without the intervention of yeast.

Once the alcohol level in each berry reaches about 2%, the grape skins start to split and release their juice. The grapes are then pressed, and the juice completes fermentation with yeast in the normal way.

Resulting character: Very distinctive. Bright, vibrant fruit (kirsch, banana, bubblegum, cinnamon-like spice). Good colour but soft, almost no perceptible tannin, because the skins were never worked in alcohol. Very aromatic. The wines are meant to be drunk young.

Key region: This is the technique (or a variant of it) used for Beaujolais Nouveau and many Beaujolais wines from the Gamay grape.

Semi-Carbonic Maceration

A more common variation. Whole bunches are placed in the vessel, but no external CO₂ is added. The weight of the grapes on top crushes those at the bottom, releasing juice. This juice begins fermenting with ambient yeast, producing CO₂ naturally, which fills the vessel and creates the anaerobic conditions for intracellular fermentation in the intact berries above.

The result is a blend of traditionally fermented wine (from the crushed grapes at the bottom) and carbonic-maceration wine (from the whole berries). This produces a fresher fruit character with more aroma than a fully traditional fermentation, while retaining more structure and complexity than full carbonic maceration.

Where it's used: Beaujolais (this is actually the dominant technique, rather than full carbonic maceration), parts of the Rhône, Rioja for joven (young) wines, and some New World producers making fresh, early-drinking reds.

Whole Bunches Mixed with Crushed Fruit

The third form, and the one you meet most in premium winemaking. A proportion of whole bunches goes into the vat with crushed grapes. The whole berries are broken progressively by punching down over several days, so a little intracellular fermentation happens inside them before they join the main ferment.

Resulting character: Silkier texture and brighter, fresher fruit than an all-crushed fermentation, with the complexity of a conventional one. The more whole bunch in the vat, the more “carbonic” the fruit character. It may be followed by a post-fermentation maceration.

Where it's used: Burgundy and a growing number of Pinot Noir producers worldwide; also increasingly for Syrah and Grenache (see the grape notes below).

Rosé Production Methods

Rosé is a style, not a grape variety. It can be made from virtually any red grape. The colour ranges from pale salmon to deep pink, depending on the method and duration of skin contact. The textbook gives three methods: direct pressing, short maceration, and blending. Saignée, covered here as a note, is a way some rosé comes about as a by-product of red winemaking rather than a fourth method in the exam framework.

1. Direct Press (Pressing Immediately)

Red grapes are pressed immediately after harvest, just like white grapes. Because the juice is in contact with the skins for only a very short time during pressing, only a small amount of colour is extracted.

Resulting style: Very pale, delicate, light-bodied. Often the palest, most elegant rosé styles. This is the dominant method in Provence, which produces the benchmark pale, dry rosé style.

2. Short Maceration

Red grapes are crushed and left in contact with their skins for a short period, typically a few hours to 2–3 days: before the juice is drawn off and fermented separately, like a white wine.

Resulting style: More colour and body than direct-press rosé. The depth of colour depends on the duration of maceration. This is the most common method worldwide for rosé production.

3. Blending Red and White Wine

A small amount of red wine is added to a white wine to produce a pink wine. It is the red that is the minor partner.

Where it's allowed: This method is not allowed in many European GIs for still rosé. However, it is the standard method for making rosé Champagne and is also common in the New World (Australia, the US) where regulations are less restrictive.

Resulting style: Varies depending on how much red goes in. The method gives the winemaker precise control over colour.

A note on saignée (bleeding): A winemaker making red wine sometimes “bleeds off” a portion of juice from the vat early on, after a short period of skin contact, to concentrate the red that remains. That bled-off pink juice can be fermented as rosé. It is really a short-maceration rosé that arrived as a by-product, often darker and fuller than a rosé made on purpose, and its quality depends on whether the winemaker takes it seriously. Useful to know; not one of the textbook’s three methods.
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Exam Tip

Know the three rosé methods and where each is typically used. The most common exam distinction: blending red and white is not allowed for still rosé in many European GIs but is the standard method for rosé Champagne. This exception comes up regularly.

Rosé Winemaking After Colour Extraction

Regardless of the method used to achieve colour, once the juice is separated from the skins, rosé is fermented and handled essentially like a white wine: cool fermentation in stainless steel, no MLF (to preserve freshness), early bottling. Oak is rarely used. The goal is almost always a fresh, fruit-forward, dry wine for immediate consumption.

How Winemaking Choices Create Different Red Wine Styles

Decision Light, Fruity Style Full, Structured Style
Maceration time Short (5–8 days) Long (3–4+ weeks)
Cold soak Optional or none May use for colour without harsh tannin
Fermentation temp Lower (20–25°C) Higher (28–32°C)
Cap management Gentle, less frequent Vigorous, more frequent
Post-ferm maceration None Days to weeks
Oak maturation None, or old oak French oak, part new, typically 12–18 months
Carbonic maceration Possible (Beaujolais) Not used
Resulting wine Beaujolais, young Rioja, basic Pinot Noir Top Bordeaux, Barossa Shiraz, Napa Cabernet

Key Red Grape Varieties and Winemaking Approach

Cabernet Sauvignon

Small berries with thick skins yield deep colour, high tannin, and concentrated blackcurrant flavour. In the winery: destemmed and crushed (the stems would add herbaceous, astringent notes), often a cold soak, then fermented at 26–30°C, with the winemaker easing off extraction late in the fermentation while the tannins are still unripe. Post-fermentation maceration is used by some. Matured mostly in French oak, 225-litre barriques, for a typical 12–18 months; the trend is away from all-new barrels. Frequently blended: with Merlot in Bordeaux, Shiraz in Australia, Sangiovese in Italy, Tempranillo in Spain. Benchmark regions: the Haut-Médoc, Napa Valley, Coonawarra, Margaret River, Hawke’s Bay, Stellenbosch, Colchagua.

Merlot

Buds and ripens earlier than Cabernet Sauvignon. Two styles: a late-picked “international” style, full and plummy, and the fresher, leafier, earlier-picked Bordeaux style. Its skins are more supple, so it needs less extraction and gentler cap management. It takes well to new oak, with 12–18 months common. The blending partner that adds generosity and mid-palate flesh.

Pinot Noir

Thin-skinned berries produce pale-coloured wines with delicate red fruit character. It buds and ripens early, comes in many clones, and wants a cool or moderate climate: too cool a vintage gives cabbage and wet-leaf notes, too hot a site gives jam. The aim in the winery is as much extraction as the fruit can take without overworking it. Most producers destem and use a pre-fermentation cold soak to pull out colour and flavour; a growing number include whole bunches for red fruit and floral lift. Fermentation temperatures often rise above 30°C. Post-fermentation maceration is not widely used. Matured 12–24 months in French oak, mostly older barrels, and not usually blended. Regions with a reputation: the Côte d’Or above all, then Baden, Carneros and Sonoma, Martinborough, Marlborough and Central Otago, Yarra Valley, Mornington Peninsula and Tasmania, Walker Bay, Casablanca.

Syrah/Shiraz

Small, thick-skinned grapes producing deeply coloured wines with dark fruit, black pepper, and savoury character. It needs warmth: the Northern Rhône is its cool limit, which is why the best sites there (Côte-Rôtie, Hermitage) are south-facing slopes. The Hunter and Barossa are warm; Great Southern, Geelong and Heathcote are cooler and more peppery. Style depends on climate and on the producer’s approach. One philosophy: vigorous extraction and plenty of new oak. The other: earlier picking, gentle cap management, whole bunches, longer post-fermentation maceration, and larger (300–500 litre) and older oak in place of new barriques. That second approach is spreading even in warm regions, so don’t treat “Barossa in new American oak” as the default.

Grenache/Garnacha

Late-ripening, drought-tolerant, thin-skinned. Naturally high alcohol, low acidity, soft tannin, and pale colour. Rarely bottled on its own: Carignan and Mourvèdre add freshness, tannin and colour in Priorat (with Carignan), Rioja Oriental, Calatayud, Cariñena and Navarra, Châteauneuf-du-Pape (with Syrah and Mourvèdre) and the Languedoc-Roussillon blends; Australia has old bush vines in the Barossa and McLaren Vale. In the winery: destemmed, a cold soak is common, some whole bunch, open-top vessels, gentle cap management, sometimes a post-fermentation maceration. Matured in large old oak (foudres), because new oak overwhelms it. In warm climates, the key challenge is managing the naturally high sugar levels that can produce uncomfortably high alcohol.

What the Exam Expects You to Know

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Short Answer Strategy

If asked how winemaking choices affect the style of a red wine, use the cause → effect framework. Don't just list techniques, explain the impact of each. For example: "Long maceration at high temperatures extracts high levels of tannin and colour from the skins, producing a deeply coloured, full-bodied wine with firm tannin structure and significant ageing potential. This approach is used for premium Cabernet Sauvignon in regions like Bordeaux and Napa Valley."

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