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.
- 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: Mainly for lighter red grape varieties (Pinot Noir, for example) where the winemaker wants maximum colour but gentle tannin. 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.
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.
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.
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. 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.
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).
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. However, the tannins extracted during this phase tend to be softer and more polymerised than those extracted during fermentation. Some winemakers believe this produces a smoother, more velvety tannin structure in the finished wine.
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. The winemaker will typically keep these separate and blend them later in whatever proportion achieves the desired style.
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:
- It softens the wine by converting sharp malic acid to gentler lactic acid
- It adds stability (a wine that hasn't completed MLF may undergo it unpredictably in bottle, producing unwanted CO₂)
- The buttery character from MLF is less dominant in reds because of the tannin and fruit intensity, so it adds subtle complexity rather than an obvious flavour
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.
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.
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.
Carbonic and Semi-Carbonic Maceration
These are fundamentally different approaches to red winemaking that produce light, fruity, aromatic wines with very soft tannins, the opposite of the structured, age-worthy style described above.
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). Soft, almost no perceptible tannin. 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.
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. There are four main methods:
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. Saignée (Bleeding)
A winemaker making red wine "bleeds off" (saigne) a portion of the juice from the fermentation vessel early on, after a short period of skin contact. This bled-off juice, which has picked up some colour, is then fermented separately as rosé.
Resulting style: Often darker and more full-bodied than other rosé methods, because the primary purpose is to concentrate the remaining red wine (by removing liquid, the ratio of skin to juice increases in the red wine vat). The rosé is a by-product.
Important nuance: Saignée rosé is not always made with the rosé as the primary goal, it's the red wine that drives the decision. The quality of the rosé can vary depending on whether the winemaker treats it as a serious product or just a by-product.
4. Blending Red and White Wine
A finished red wine is blended with a finished white wine to produce a pink wine.
Where it's allowed: This method is prohibited for still rosé in the EU (with few exceptions). 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 the proportion of red to white wine. The method gives the winemaker precise control over colour.
Exam Tip
Know all four rosé methods and where each is typically used. The most common exam distinction: blending red and white is prohibited for still rosé in the EU 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. 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 | New French oak, 12–24 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. Typically receives long maceration and new oak ageing (12–24 months). The tannin structure and oak character are central to the style. This is the classic grape for full-bodied, age-worthy red wines (Bordeaux Left Bank, Napa Valley, Coonawarra).
Merlot
Larger berries with thinner skins produce softer, rounder wines with plum and red fruit character. Lower tannin than Cabernet Sauvignon. May receive shorter maceration and less aggressive cap management. Often matured in oak, but with a lower proportion of new oak than Cabernet Sauvignon. The blending partner that adds generosity and mid-palate flesh.
Pinot Noir
Thin-skinned berries produce pale-coloured wines with delicate red fruit character. Requires gentle extraction: punching down rather than pumping over, moderate temperatures, and shorter maceration. Whole-bunch inclusion is common for complexity. Matured in French oak (often a mix of new and old) for subtlety. The winemaker's grape, every decision is magnified in the final wine.
Syrah/Shiraz
Thick-skinned grapes producing deeply coloured wines with dark fruit, black pepper, and savoury character. Winemaking ranges from elegant and restrained (Northern Rhône: whole bunches, old oak or large vessels) to powerful and oaky (Barossa Valley: long maceration, new American oak). The same grape, two philosophies.
Grenache/Garnacha
Thin-skinned, prone to oxidation. Naturally high alcohol, low tannin, and pale colour. Often co-fermented or blended with Syrah and Mourvèdre (the classic GSM blend) to add colour and structure. Careful extraction is needed to avoid harsh tannins from the thin skins. In warm climates, the key winemaking challenge is managing the naturally high sugar levels that can produce uncomfortably high alcohol.
What the Exam Expects You to Know
- Why skin contact is essential for red wine (colour, tannin, flavour extraction)
- The difference between pre-fermentation, fermentation, and post-fermentation maceration
- The four main cap management techniques and how they differ in aggressiveness
- How fermentation temperature and maceration time affect the style of red wine
- The difference between free-run wine and press wine
- How carbonic and semi-carbonic maceration work and what style of wine they produce
- The four rosé production methods and where each is used
- Why blending red and white is prohibited for still rosé in the EU but allowed for Champagne rosé
- The three contributions of oak to red wine: flavour, tannin, and texture (micro-oxygenation)
- French vs American oak differences
- New vs old oak and the effect on wine flavour
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."
Active Recall Prompts
Close this page and try to answer these from memory:
- Why is pressing done after fermentation in red winemaking but before fermentation in white?
- Describe the purpose of a cold soak. What does it extract, and what doesn't it extract? Why?
- Name the four cap management techniques in order from gentlest to most aggressive.
- What is the difference between free-run wine and press wine? How does the winemaker use each?
- Explain carbonic maceration step by step. What kind of wines does it produce?
- Name the four methods of rosé production and give one example region for each.
- Why is blending red and white wine to make rosé generally prohibited in the EU?
- Compare punching down and pumping over. When would a winemaker choose each?
- How does the choice between French and American oak affect a wine's flavour profile?
- Describe how you would make a light, fruity red wine vs a full-bodied, structured one. What changes at each step?