Chapter 3

Principles of Winemaking

Harvesting

By and large, harvesting begins once the grapes have reached optimal phenolic and sugar ripeness. If it is not operationally possible to harvest all the grapes at optimal ripeness, then it is a matter of compromising. Grapes that are harvested too early can introduce unripe, ‘green’ notes into the wine, while grapes that are harvested too late can make for a flabby or jammy wine. Many wines are made from a blend of fruit from multiple vineyards, in which case the grapes may be harvested at the best time (or close to the best time) for each individual site. The grower must also take weather conditions into account: for instance, if a storm is imminent, it may be judicious to bring in the grapes even if they are still slightly under-ripe.

In many cases, large harvesters are driven through the vineyards. These machines beat the vines with rubber sticks, shaking off the grapes onto a conveyor belt that transfers them into a holding bin. Harvesters enable the grapes to be harvested quickly, day and night, without the cost or labour associated with hand harvesting. Some modern harvesters can even be controlled remotely through computers and GPS tracking systems. On the other hand, harvesters are expensive, can only operate on flat or gently sloping land, and place restrictions on planting and trellising. They can also damage the grapes, colouring the juice and exposing it to oxygen. Ambitious producers invariably prefer hand harvesting, which is both gentler and more selective. Pickers can be trained to recognize and discard rotten or under-ripe bunches and even to select individual berries that have been infected with noble rot. They can also pick whole bunches, which can be either desirable, as in Champagne, or necessary, as in much of Beaujolais.

After harvesting, the grapes must be transported to the winery as fast as possible to minimize oxidative damage, and some large estates operate a number of pressing stations in or near the vineyards. Otherwise, transiting grapes can be protected from oxidation with a dusting of antioxidant powder, typically potassium metabisulphite (sulphur dioxide) or a blanket of carbon dioxide. Once the grapes have been pressed and transformed into juice, it becomes much easier to protect them from oxidation. In warmer climates and conditions, and with aromatic white wines, it is especially important to keep the picked grapes cool to limit biochemical degradation. Grapes are often harvested at night or first thing in the morning and may be refrigerated, especially if long transports are required.

Crushing and pressing

Upon arrival at the winery, the grapes are spread onto a sorting table fitted with a conveyor belt and undesirable material is discarded, either by hand or by an automated process. This includes under-ripe and rotten grapes, leaves, twigs, and large insects. If the grapes have been hand harvested, a decision has to be made as to whether to remove the stems. Although they add to bulk and volume, stems create drainage channels that increase the efficiency of the pressing process. If ripe, they can also contribute good tannins and flavour; if not, they can introduce bitter tannins and vegetal notes. Stems can also absorb colour and alcohol. Increasingly, winemakers who know their grapes and know their stems are experimenting with various degrees of whole bunch fermentation to bring extra elegance and expression to their wines. The process of de-stemming involves feeding bunches through a rotating drum perforated with grape-sized holes. The bare stems are sometimes collected and added back at a later stage, either to reduce cap compaction or contribute extra tannins and flavour.

Next, the juice must be extracted from the grapes by crushing and/or pressing. Less commonly, the grapes are left intact to ferment. In crushing, the grapes are passed through a pair of rollers and the grape skins are ripped open. The rollers mimic traditional crushing by the human foot, which is still occasionally practised in some places such as Georgia and the Douro. The crusher is carefully calibrated to avoid damaging pips and stems and releasing bitter tannins and vegetal notes into the free-run juice.

The lightest and most delicate white wines are made exclusively from the free-run juice obtained by crushing, which contains none of the colour and tannin of the grape skins, pips, and stems. However, many white wines benefit from at least a small degree of ‘skin contact’, with the free-run juice left on the skins for a short period. Rosés are made in a similar fashion on the skins of black grapes, especially in the European Union, which, with the notable exception of Champagne, forbids the blending of white and red wine. Depth of colour varies according to duration of skin contact, which for rosé typically lasts one-to-three days. As the juice of almost all grape varieties is clear, red wines depend for their colour, and indeed most of their tannins, on contact with skins, pips, and sometimes also stems, which are said to be ‘macerating’ in the juice. ‘Must’ is the collective term for the juice and solid matter.

For most white wines, the free-run juice is augmented by juice extracted by pressing the grapes. Indeed, some economy-conscious winemakers entirely forgo crushing in favour of pressing alone. Pressing releases juice from the cells on the inner surface of the grape skins, along with aroma, flavour, and polyphenols. A traditional wine press consists of a slatted basket with spaces between the slats and a lid that is screwed down to press the grapes. Pressing inevitably involves the release of bitter polyphenols, and the winemaker must strike a balance between volume and quality. Today, most winemakers use more gentle and efficient presses such as the Willmes pneumatic press. With the Willmes, grapes are loaded into a horizontal, perforated cyclinder with a rubber bladder running through the centre. The bladder is then inflated with air so as to exert gentle pressure on the grapes. For red wines, the grapes are also pressed, but after fermentation. During fermentation, the skins macerate in the juice, releasing colour and tannin.

Crushing and pressing ought to be carried out efficiently, with minimal exposure to oxygen. The addition of sulphur dioxide to the must can protect against oxidation but can also impede fermentation (which can be desirable if the must is to be clarified prior to fermentation, a process that can take several days). The high polyphenols in red wines offer some protection against oxidation. Even so, some sulphur dioxide may be added to assist in polyphenol extraction. The use of sulphur dioxide can be minimized by refrigerating the must, although this too can impede fermentation. True anaerobic pressing can be achieved with a tank press, which is essentially a Willmes enclosed in a tank flushed with inert nitrogen. However, it is possible to take protection from ­oxidation too far, resulting in a foul smelling ‘reductive’ wine (Chapter 4).

Prior to fermentation, the must can be adjusted to suit the winemaker’s purposes. Especially in marginal climates, the must might be enriched with sugar (‘chaptalized’) to increase the potential alcohol of the wine. Cane or beet sugar is commonly used. The must might also be deacidified by the addition of a carbonate or bicarbonate compound. Conversely, in hot regions, wines may be acidified by the addition of tartaric acid. Acidification can bring balance to a wine, but poorly or overly acidified wines can come across as bitter, poorly integrated, and ‘doctored’. Similarly, chaptalized wines can seem boozy and imbalanced.

Fermentation

In essence, wine results from the fermentation by yeast cells of sugar into ethyl alcohol, or ethanol. The chemical formula for this reaction is:

C6H12O6 → 2C2H5OH + 2CO2

Sugar (glucose:fructose = ~50:50) → ethanol + carbon dioxide

There are many different species of yeast, and, within each species, several genetically distinct strains. The yeast most commonly used in winemaking is Saccharomyces cerevisiae, which is efficient at fermenting sugars into ethanol and able to survive high levels of its ethanol waste product.

The winemaker pumps the must into a fermentation vessel, which can range from an airtight stainless steel tank to an open-air concrete pool to an oak barrel. He or she can either inoculate the must with a commercially produced yeast culture, or rely on the yeast cells on the grape skins and winery equipment to start a ‘natural’ fermentation. With natural fermentation, the winemaker is unable to select the best-suited strain of yeast for the wine that he or she is seeking to make; however, many winemakers maintain that natural fermentation, which typically involves several species of yeast, results in more complex flavours and aromas. Various yeast species can start the fermentation but it is invariably Saccharomyces cerevisiae that finishes it off, as it is (almost) the only yeast capable of metabolizing sugar in the presence of high levels of ethanol.

Throughout fermentation, carbon dioxide is being produced and protects the fermenting must from oxidation. This carbon dioxide needs to be let out of the fermentation vessel and, because it can lead to suffocation, the winery as well. Another by-product of fermentation is heat, and the temperature of the must may need to be controlled to keep it within the optimal range for the yeast to function. Temperature of fermentation also has a bearing on aroma and flavour. In particular, the esters that make a wine (especially a white wine) seem fruity and floral are all but lost at higher temperatures.

In most cases, the fermentation naturally comes to an end when the yeasts run out of nutrients, typically after one-to-two weeks. The wine has then been fermented ‘to dryness’, meaning that there is very little sugar left in it. In some cases, the initial sugar levels are so high that the alcohol produced kills off all the yeasts, resulting in a wine with substantial residual sugar. This is one way of making an off-dry or sweet wine. Alternatively, the fermentation can be artificially terminated by filtering out the yeasts or killing them by, for example, pasteurization or the addition of sulphur dioxide or alcohol (fortification). Unless the wine is being fortified, artificial termination of fermentation generally results in a wine with low alcohol and high residual sugar.

While conversion of sugars to ethanol is the predominant reaction, it is only one of potentially thousands of biochemical reactions taking place during fermentation. As a result, wine contains trace amounts of a large number of organic acids, esters, sugars, alcohols, and other molecules. Wine is, in fact, one of the most complex of all beverages: the fruit of a soil, climate, and vintage, digested by fungi through a process guided by the culture, vision, and skill of an individual man or woman.

White wines

There are almost as many approaches to fermentation as there are wine-makers. This section covers the most common techniques for white wines, red wines, and rosés. Sparkling wines and fortified wines are covered in Chapters 11 and 21, respectively.

For white wines, the must is usually fermented in the absence of solid matter. Skin contact for the extraction of polyphenols, if any, occurs prior to the onset of fermentation. For a fresh, fruity, and vibrant style, fermentation is carried out in sealed, inert vats, usually made from stainless steel, with active temperature control to keep the must from becoming too warm. For a more complex style rich in secondary aromas and flavours, a more traditional vinification is preferred. Large vats and small barrels made of oak have found particular favour, and can be used for both fermentation and maturation. The porous wood allows a small degree of air exchange, which facilitates the development of more complex aroma and flavour compounds. Other alternatives include vats of concrete or clay, including the concrete egg, which harks back to the Roman amphora or Georgian kvevri, and glass demijohns. Concrete eggs promote circulation with the lees continuously in movement, which adds depth and structure to the wine without the need for lees stirring (see later). They also minimize evaporation, stabilize fermentation temperatures, and allow the wine to breathe as in oak but without imparting oak aromas and flavours. On the other hand, concrete eggs are initially very costly and difficult to transport, and need protection against acid corrosion.

Red wines and rosés

Red wines rely on contact with the grape skins, pips, and sometimes also stems for their colour, phenolics, and tannins. Rosés and light red wines may undergo no more than cold maceration before the juice is drained off for fermentation. However, most red wines are fermented together with the solid matter, or pomace (marc), for at least part if not all of the process. Fermentation temperatures are higher than with white wines, 20-30°C versus ≤15°C, to enhance extraction of colour and polyphenols. The carbon dioxide released from fermentation forces the pomace to the top of the vat, where it is pressed into a solid cap (chapeau de marc).

The cap needs to be broken down at frequent intervals to return the solid material to the fermenting juice. This can be achieved by one or more of punching down, pumping over, and racking and returning, which, according to their application, become methods of controlling colour extraction and quantity and quality of tannins. Of the three, punching down (pigeage) is the most ancient, and involves pressing the cap to the bottom of the vessel, traditionally with a flat disc attached to a pole. It is a gentle process that minimizes the release of bitter tannins from the outermost cells of the grape skins. Pumping over (remontage) involves extracting the juice from the bottom of the vat and pumping it onto the cap, thereby re-submerging it. This can be achieved with anything from manually operated hoses to automated fermentation vats with nozzles that spray the juice onto the cap. Racking and returning (délestage) involves draining all the juice from the fermentation vat into a second vessel and then returning it to the original vat by spraying it over the cap. Racking can also be used at other stages of the winemaking process to separate the juice or wine from the solid matter that has accrued at the bottom of the vat. Cos d’Estournel in Bordeaux and Vega Sicilia in Ribera del Duero go so far as to carry up the juice in ‘elevator tanks’ to avoid stressing it with pumps and pipes! At any point, the wine can be pumped off the solid matter to continue fermenting in a separate vessel, which is another method of making rosé.

Carbonic maceration

In carbonic maceration, bunches of intact grapes are placed in a closed vat and smothered in carbon dioxide. The gas inhibits conventional fermentation; instead, fermentation takes place through an intracellular process driven by natural enzymes within the grape. This process releases further carbon dioxide that bursts the skins open. After one-to-two weeks, the semi-liquid must arrives at an alcoholic strength of about 3%, after which it is pressed and transferred to another vat for a conventional yeast fermentation. Wines produced by carbonic maceration are invariably red, and noted for their vibrant fruity and estery aromas. The archetype is Beaujolais Nouveau, a wine so approachable as to be ready for market within just a few weeks of harvest. Sometimes, only part of a wine is made by carbonic maceration and blended in for a subtle estery effect.

A variant of carbonic maceration is semi-carbonic maceration, in which bunches of intact grapes are placed into a vat. The berries at the bottom of the vat are crushed by the weight above them and undergo yeast fermentation. This releases carbon dioxide onto the berries higher up, which in turn undergo intracellular fermentation.

Malolactic (secondary) fermentation

After the alcoholic, or primary, fermentation, the wine may remain in the fermentation vat to undergo a secondary fermentation. The most common type of secondary fermentation is malolactic fermentation, or, more properly, malolactic conversion, which principally involves the decarboxylation of malic acid to form lactic acid and carbon dioxide. Although often inoculated, lactic acid bacteria such as Oenococcus oeni are naturally present in the must (assuming that it has not been sterilized) and spontaneously begin the malolactic conversion once the alcoholic fermentation has been completed, or even before. Compared to malic acid, lactic acid is softer and richer on the palate. Lactic acid is found in high concentrations in soured milk products, and white wines that have undergone malolactic conversion can display a yogurt or dairy note.

Almost all red wines undergo malolactic conversion, sometimes over several weeks. As well as reducing acidity and adding texture and complexity, malolactic conversion stabilizes the wine, preventing a later malolactic conversion in the bottle, which could make for a turbid, slightly carbonated product smelling of sauerkraut. With white wines such as Riesling, Gewurztraminer, and Sauvignon Blanc, the winemaker typically suppresses the malolactic conversion, often by adding sulphur dioxide, to retain the sharpness of the malic acid and the fruity and floral aromas and flavours. Chardonnay on the other hand commonly benefits from malolactic conversion, developing a fuller texture and notes of butter or butter popcorn (diacetyl). Many champagne houses encourage malolactic conversion, although some, most notably Lanson, prefer to eschew it.

Maturation

The simplest wines are bottled almost immediately after fermentation. Most wines, however, benefit from a period of post-fermentation maturation. White wines might be kept in contact with the lees, which consist primarily of dead yeast cells, for some time after fermentation. Lees ageing adds to the texture and complexity of the wine and imparts notes of yeast, bread, brioche, and biscuit. Champagne undergoes lees ageing after the second, bottle fermentation, and much quality Muscadet is left sur lie for several months before being bottled. The lees may be stirred through the wine at regular intervals in a process called bâtonnage, which increases lees contact and encourages oxygen to percolate to the lees. In the relative absence of oxygen, the reactions involved in the enzymatic decomposition of the lees can lead to an accumulation of foul-smelling hydrogen sulphide.

The Romans adopted the Gaulish custom of storing beer and other liquids in oak barrels to facilitate the transportation of wine throughout their extensive empire. Compared to many other woods, oak had the several advantages of being soft, pliable, tight-grained, and abundant. Today, wine is commonly matured in oak barrels, which, although watertight, allow small amounts of oxygen to filter into the wine. Too much oxygen can damage a wine, but a small amount, so-called natural micro-oxygenation, has a number of beneficial effects, including enhancing colour stability and intensity, dispelling reductive and vegetative notes, and, above all, polymerizing and thereby ‘softening’ astringent tannin compounds.

In the main, three species of oak are used: American oak (Quercus alba) and two species of French oak. Of the two French species, the sessile oak (Quercus petraea/sessiflora) is tighter grained than the pendunculate oak (Quercus robur/pedunculata). Oak trees too are influenced by terroir, and oak from particular forests such as Allier, Tronçais, and Nevers may be particularly sought-after for their flavour profiles. Until supplies were cut off in the early 20th century, many French winemakers favoured oak from Eastern Europe, especially the smaller and slower growing sessile oak from the Zemplén Mountains in Hungary, which is said to be ‘more French than French’. American oak barrels are substantially less expensive than French because American oak has a tighter structure that allows it to be sawn, whereas French oak has to be split along the grain of the wood if it is to remain watertight. American oak is low in tannins and high in aromatics, imparting notes of coconut and vanilla to the wine. French oak imparts more subtle notes of vanilla, toast, caramel, spice, cedar, and smoke. French oak is also high in tannins and can add appreciably to the structure of a wine.

To make top quality barrels, staves of wood are seasoned outdoors for up to three years to leach out the bitterest compounds. The wood is then toasted over a brazier to bend the staves into shape. This charring process brings out certain flavour compounds, and the degree of toasting is another important determinant of a barrel’s flavour profile. Some winemakers source barrels from different regions and cooperages with various levels of toasting to enhance the complexity of their wines.

The most common barrel sizes are the Bordeaux barrique of 225l and the shorter, fatter Burgundy barrel of 228l. Didier Dagueneau of Pouilly-Fumé in the Loire experimented with a longer, narrower ‘cigar barrel’ of 265l that aims to maximize lees contact. A barrel’s surface area to volume ratio has an important bearing both on the micro-oxygenation effect and on the transfer of flavour compounds. Maximum flavour is imparted from the barrel on first use, when it is referred to as ‘new oak’.

A winemaker may mature a variable proportion of a wine in new oak and the remainder in old oak or a neutral vessel and then blend the two together. Commonly, the winemaker renews a certain fraction of the barrels every year. If, for example, he or she renews a quarter of the barrels every year, the wine will be aged in 25% new oak, 25% two-year-old oak, 25% three-year-old oak, and 25% four-year-old oak. Old oak barrels can be sanded and re-toasted, but this undermines their structural integrity and is not best practice. Some wines, for example, Bordeaux blends and Rioja, are well suited to a high proportion of new oak; whereas others, for example, Pinot Noir, Rhône reds, and many Italian reds, are better suited to a high proportion of old oak. Yet other wines, especially aromatic white wines such as Riesling or Sauvignon Blanc, are not generally suited to oak ageing, which masks or detracts from their qualities. There are of course important exceptions to these principles, such as Grand Cru Burgundy and Sauvignon Blanc from Graves in Bordeaux, which are commonly aged in a high proportion of new oak.

A number of techniques aim to replicate some of the properties of oak ageing at a small fraction of the cost. These include adding ‘oak flavour’ powder or inserting oak staves or a giant ‘teabag’ of oak chips into the wine. Unfortunately, the resulting oak influence usually comes across as clumsy and poorly integrated. To mimic the micro-oxygenation effect of oak ageing, some winemakers introduce small amounts of oxygen through a ceramic diffuser at the bottom of the vat, often with good results.

Clarification and stabilization

After vinification and maturation, which may last anything from a few months to several years, the wine is prepared for bottling. In some cases, the wine may be blended from a number of base wines with the aim of improving quality, complexity, and consistency. These base wines may consist of different grape varieties or fruit from different vineyards, vinification vats, or maturation vessels.

The wine may need to be clarified to remove suspended solids, and stabilized to prevent degradation. A wine can be clarified by racking it off its lees in what can be a long and laborious process. Many winemakers save time and effort by using one of several techniques, most commonly fining or filtration. Fining involves the addition of a clarifying substance, traditionally egg white, which causes particles to precipitate, and which is subsequently removed along with the particles. Fining, although often thought of solely in terms of clarification, can also be directed at removing excessive colour, off-flavours and odours, and bitterness or astringency.

Some white wines are susceptible to the gradual accretion of harmless tartrate crystals (potassium bitartrate, cream of tartar), which can form precipitously if the wine is exposed to colder temperatures. Aficionados look upon these ‘wine crystals’ or ‘wine diamonds’ as a sign that the wine has not been overly processed, but less experienced consumers are liable to mistake them for shards of glass. So as not to have bottles returned, the winemaker may decide to bring the wine to near freezing point to precipitate and remove the crystals. Unfortunately, this ‘cold stabilization’ adds nothing to the wine, and, indeed, may even subtract from it.

Any potentially damaging microorganisms that still remain in the wine ought to be removed or killed to guard against spoilage, including malolactic conversion or a second fermentation on residual sugar. The winemaker may add sulphur dioxide to the wine or filter it to remove the microorganisms, in which case the bottles and bottling equipment must be kept sterile. Alternatively, he or she may first bottle the wine and then pasteurize it.

A wine crafted with patience and skill is naturally clarified and free from damaging microorganisms, and might be bottled without suffering any of the above interventions. Many quality-conscious winemakers minimize clarification and stabilization to avoid removing from the colour, aroma, flavour, texture, or ageing potential of their wine.

Some winemakers go even further and produce a ‘natural’ wine. A natural wine is a wine made from handpicked grapes from a biodynamic or organic farm, with minimal manipulation in the cellar. Criteria accepted by most natural wine producers and organizations include: no foreign yeasts, no added sugars, no acidity adjustments, no or minimal contact with new oak, no or minimal fining or filtration, and no or minimal sulphites. Natural wine can be regarded as a reaction to doctored, engineered, or ‘industrial’ wines, and entails the extension of organic and biodynamic principles into the cellar. It is, of course, a risky business, but the most successful examples are wines of great vivacity, with a broad yet harmonious spectrum of flavours, silky texture, and strong sense of place.

Bottles

Most wines are bottled in what has become a standard 750ml glass bottle. It is sometimes said that the barrique is 225l because that is the largest size a man could carry, and that the bottle is 750ml because that is the largest size a glassblower could blow. Other bottle sizes include piccolo (equivalent to 1/4 of a standard bottle), demi (1/2), magnum (2), jeroboam or double-magnum (4), methuselah (8), salmanazar (12), balthazar (16), and nebuchadnezzar (20). Sweet wines often come in a 500ml jennie, and Vin Jaune from the Jura in a 620cl clavelin.

As well as different sizes, wine bottles can have different shapes, which, in many cases, have become enshrined in EU law. The three most common shapes are the Bordeaux bottle, which is straight-sided and high-shouldered with a pronounced punt (the indentation at the bottom of a bottle); the Burgundy and Rhône bottle, which is tall with sloping shoulders and a smaller punt; and the Mosel and Alsace or hock bottle, which is narrow and tall with little or no punt. The punt may well be a vestige from a time when bottles were blown with a blowpipe and pontil. Other possible explanations for the punt include: catching sediment; strengthening or stabilizing the bottle; making the bottle easier to handle, store, or transport; and impressing/deceiving the customer by making the bottle larger. Alternatives to glass bottles include plastic bottles, cardboard bricks, and metallic-plastic bags set in cardboard boxes, none of which outperform glass bottles for long-term storage.

Closures

Cork, the traditional closure, is harvested from the cork oak tree (Quercus suber). It is elastic and watertight, but allows a tiny amount of air exchange which guards against the development of reductive odours as the wine matures. Problems with cork hygiene from the 1960s, when the wine industry was booming, led to an increase in the frequency of ‘cork taint’ (Chapter 4). This prompted the development of alternative closures such as stoppers made from reconstituted cork, synthetic ‘corks’, aluminium screw caps, and glass stoppers fitted with a plastic washer seal. Some of these closures have been engineered to ‘breathe’, and can boast a more consistent rate of oxygen ingress than genuine cork. Many producers, notably of New Zealand Sauvignon Blanc, prefer screw caps on the grounds that they preserve volatile aromas.

Debate and research into the ‘best’ closure is ongoing. Some of the world’s top producers are carrying out longitudinal studies with a single wine under multiple closures. As the finest wines can take decades to mature, a definitive answer may yet have to wait. Meanwhile, the quality of cork is improving and instances of cork taint are now much less common. It has even become possible to test each individual cork by a simple albeit time consuming process called ‘dry soak sensory screening’. For many purists, the aesthetics of the customs, movements, and sounds associated with uncorking a bottle, not to mention the secret pleasure in calling out a corked sample, easily outweigh the small risk of cork taint. Today more than ever, the presence of a true cork is an indication of a quality wine that can be expected to improve with age.

Bottle ageing

If stored correctly at a constant temperature of about 10-15°C and out of direct sunlight, a fine wine continues to evolve through a plethora of complex chemical reactions. Their net effect is to lend the wine ‘tertiary’ notes that complement the primary fruit profile and secondary notes from the winemaking. Over time, often several years, the primary fruit recedes and tertiary notes such as earth, mushroom, and truffle come to the fore. The oak flavours become more integrated, and the tannins polymerize and ‘soften’. The larger the bottle size, the more gradual these changes, such that, in time, a wine matured in a standard 750ml bottle can taste quite different to the same wine matured in a magnum or jeroboam.

In the course of ageing, a wine may slip into a dumb phase or age ingrat with muted aromas and flavours. The drinking window of a wine is perhaps best described as the period during which all its elements come into harmony. This is partly a matter of taste: for instance, the Bordelais prefer to drink their wines at about five-to-seven years old, whereas many British would look upon this as infanticide. According to Coates’s Law of Maturity, a wine will remain within its drinking window for as long as it took to reach it. For instance, if a wine took five years to reach its drinking window, it will remain within that window for another five years. Unfortunately, nothing lasts forever, and the process of maturation is also one of decay: wait too long, and you’ll be pouring yourself something that looks and tastes like death.

One of the saddest things about ageing is that, as you get older, old wines will seem less old.