Sherry Flashcards
What is Sherry and explain its history?
Sherry is a fortified wine made in the area around the city of Jerez in Andalusia. This area has a long history of growing grapes and producing wines that dates back to the rule of the Phoenicians. Even from these early times, Sherry was a wine that was widely traded. During the period of Moorish rule from the 8th to the 13th centuries meant wine consumption was prohibited, but vineyards and wine production continued. After Jerez came under Christian rule in the 13th century both domestic consumption and exports grew rapidly as English, Irish and Flemish traders began to ship the wines. The wines further benefitted from free trade agreements with France and England, and after Christopher Columbus had discovered America from his base in Andalusía, large volumes of Sherry were also shipped to America. The next few centuries saw both challenging and prosperous periods for the Sherry industry. A number of events including the Peninsular Wars and then the plague of phylloxera devastated the industry, yet in calmer periods, several successful shipping businesses were established.
The popularity of Sherry in the late 19th and early 20th centuries meant that other countries began to produce their own, often poor- quality, ‘Sherries’ and in 1933, Spain’s first wine-related Regulatory Council, the Consejo Regulador, was formed, setting regulations to control the production and trading of Sherry wines.
Although Sherry sales fell during the Second World War, they recovered in the decades following, and Sherry sales reached their peak in the 1970s, with shipments reaching 1.5 million hL in 1979.1 However, this figure halved in the following decade as younger generations of consumers sought out different styles of wines. The fall in demand resulted in a surplus of Sherry, largely formed of cheap and low quality wines.
During the boom years the production of Sherry rose dramatically. As demand decreased, there became a surplus of cheap Sherry that had not been produced with quality in mind.
Since this time, the Consejo Regulador has been working hard in the following years to bring vineyard plantings, stock levels and sales back into balance, and to promote the quality of Sherry.
Explain Sherry’s location and climate?
Located in Andalusía in southern Spain at low latitude (36°) and with low altitude (0–90 metres above sea level), with influences from the Atlantic Ocean, Jerez has a hot Mediterranean climate with hot, dry summers and mild, relatively rainy winters.
The Atlantic also brings a cool, damp wind called the poniente that provides a cooling, humid influence in the summer. However, the levante, a hot, drying wind from north Africa, can make the climate more arid. This can cause grapes to transpire more quickly, concentrating the sugars. Too much sugar can be a negative because it may become difficult to ferment the wine to dryness, which is particularly problematic for the development of the flor yeast that is integral to the style of some Sherry wines (see Biological Ageing in Maturation, Winemaking).
Jerez experiences a high number of cloud-free days therefore sunlight hours in the growing season are high, helping to give fully ripe grapes but also meaning that without sufficient shading, grapes can easily become sunburnt.
The grapes for Sherry must come from the delimited area of around 7,000 hectares known as the Zona de Producción or Marco de Jerez. Grapes grown in this zone can either be used for DO Jerez-Xérès-Sherry or DO Manzanilla – Sanlúcar de Barrameda (or the denomination of origin for Sherry vinegar). There is one exception to this rule; the grape variety, Pedro Ximénez (also called PX), can be grown around Montilla (within Andalusía, in the mountains above Malaga, but outside the Zona de Producción) but matured in the Zona de Crianza and still be labelled as DO Jerez-Xérès-Sherry.
The Zona de Producción is split into two parts: Jerez Superior and Jerez Zona. Jerez Superior is thought to be made up of the better vineyard sites, all located on albariza soil, and makes up over 90 per cent of the plantings.
The vineyards of Jerez are also divided into smaller delimited areas called pagos. Each is thought to produce wines with different characteristics than the others, a function of factors such as aspect, location, small differences in soil etc. Legislation to allow producers to name a pago on their wine labels is currently under discussion.
Explain albariza soils?
The key soil is albariza, a mixture of limestone, silica and clay. The clay means that albariza is very effective at retaining and gradually releasing water from winter rainfall, vital in a region that is very dry during the growing season. The albariza also forms a crust when dry which is helpful in reducing evaporation from the soil surface. The ability of the albariza to retain water means that higher planting densities and yields are possible in Jerez (average 70 hL/ha) than in other regions in Spain with hot, dry climates (where low-density bush vines are required if irrigation is not used). High yields are also possible as grapes for Sherry do not need to have the same concentration of flavours as grapes for unfortified wines; most of the flavour comes through the maturation process. The light colour of the albariza soil also means that it reflects light back into the vine canopy aiding the ripening of the grapes.
What other soils than Albariza are there for Sherry production?
Other soils in the region include barros which has greater clay content and arenas which is sandy. In practice the vast majority of vines are planted on the albariza.
What grape varieties are used with Sherry and how would you describe them?
PALOMINO Palomino (also called Palomino Fino and Listán) is the principal variety, used in all dry and sweetened styles of Sherry. It accounts for almost 99 per cent of production by volume. It is mid to late ripening, well-suited to dry, sunny weather, and capable of producing large yields. However, it loses acidity quickly when it nears maturity. It is also a neutral variety and therefore does not tend to add much of its own primary aromas to Sherry wines.
MOSCATEL (Muscat of Alexandria)
Moscatel accounts for less than one per cent of production by volume. It is sometimes called Moscatel de Chipiona after the coastal town of Chipiona, around which it is mainly grown, generally on sandy arenas soils. It is late ripening and well adapted to heat and drought. In contrast to Palomino, it is an aromatic grape (grape, blossom). It is generally used to produce sweet fortified wines of the same name.
PEDRO XIMENEZ (PX) PX is also used for the production of sweet fortified wines called PX or Pedro Ximénez, and as a sweetening agent. Its small, thin-skinned grapes accumulate high levels of sugar and are then traditionally dried in the sun to further concentrate that sugar. It is a neutral variety and therefore its flavours mainly come from the drying and maturing processes. Legislation permits for it to be grown in the Montilla district in the province of Córdoba and shipped into the Zona de Producción either as fresh or raisined grapes or more likely as young wine. As for Moscatel, PX represents less than one per cent of production by volume.
Explain vineyard management practices for Sherry?
The Sherry vineyards are in the process of being transformed, mainly to accommodate mechanisation of all the annual tasks including pruning, harvesting and soil management.
The principal training system used to be replacement cane pruning, here called ‘vara y pulgar’. However, an increasing number of vineyards are now cordon trained (single or double) and spur pruned which is more suitable for mechanisation. VSP trellising ensures the canopy remains open and arranged for easy mechanisation, although some shading of the bunches is needed to prevent sunburn. While within-row spacing can be quite tight (just over 1m), between-row spacing is wide enough to allow tractors to pass.
Maximum yields permitted by the legislation are 80 hL/ha, however, it is rare that this maximum is reached, and depending on the year, yields are usually closer to 60–70 hL/ha.
The vineyards are generally planted on gentle (10–15 per cent) slopes where the albariza is mainly to be found. Each year after harvest the soil is worked to create a series of troughs or gullies down each row of vines to catch the winter rains. Without this, most of the rainwater would flow down the sloped vineyards rather than permeating the soil. This system, termed aserpia, was very labour intensive and is now mainly done mechanically.
The most widely used rootstocks are 333EM, 41-B and 13-5 EVEX (all hybrids of V. vinifera and V. berlandieri). The latter was developed by the local viticultural research station and has been found to be the most successful to date. This rootstock is tolerant of limestone soils (preventing the vine from suffering from chlorosis) and drought, while also producing good yields.
The dry growing season means that Jerez has relatively little problem with disease, however, mildew can be a problem in the spring due to warm humid weather after any rain. VSP training helps to promote air circulation to reduce the development of such diseases but, when necessary, systemic fungicides are used as treatment. The hot climate and moderating influence from the Atlantic means that frost is not an issue. European grapevine moth is a problem and often managed using pheromone traps.
Harvest begins in the first week of August starting on the more inland vineyards and finishing with the cooler coastal plots by the second week in September. Harvest tends to be as early as possible to avoid the risk of autumn rain; any rot would be very undesirable, particularly for biologically aged wines (see Maturation in Biological Ageing). The grapes are usually picked with approximately 12% potential alcohol, total acidity of around 5 g/L and pH of 3.3–3.5. Palomino loses acidity quickly in the final stages of ripening, and therefore acidification is sometimes required if levels fall much below 5 g/L.
The PX and Moscatel grapes for naturally sweet wines (see Styles of Sherry) tend to be harvested slightly later. A higher concentration of sugar in the grapes when harvested makes the drying process that follows easier and quicker.
Around 60 per cent of the total grape volume is harvested by machine mostly at night or in the early hours of the morning when temperatures are coolest to reduce chances of oxidation and microbial spoilage.
Explain the winemaking process with Sherry?
The grapes are pressed on arrival at the winery. Skin contact is not desirable, particularly for biologically aged wines (for more details, see Biological Ageing) as phenolic compounds can restrict the growth of flor yeast. These styles will tend to be made from free run juice and the lightest pressings (called the primera yema). Oloroso wines tend to be made from later press fractions that are extracted using greater pressure. The higher levels of phenolics in these pressings mean the flor struggles to develop. The final press fractions will be used for other products, such as the wine used for seasoning barrels. Free run juice and the first pressings typically makes up around 60–75 per cent of the juice yield, and therefore producers who mainly make Oloroso (e.g. Fundador), may also use free run juice in these styles. The maximum permitted juice yield is 70 L/100kg of grapes.
The must will be clarified before fermentation either by cold settling, centrifugation or flotation. The albariza soil is dusty, and therefore clarification is important to remove these particles from the must.
It is common for the musts from different vineyard sites to be fermented separately to create many different base wines (wines before fortification and maturation) that can then be blended as needed. Most producers use cultured yeasts and ferment at around 22–26°C (72– 79°F), both of which are beneficial for a reliable fermentation to dryness. The vast majority of the aromas and flavours in Palomino-based Sherries comes from the maturation process, and therefore producers are not looking to enhance fruit or other flavours during the fermentation. Fermentation generally takes place in stainless steel vessels. However, a small number of producers are using barrel fermentation (with old barrels) for some of their wines to give a fuller body.
The first phase of fermentation is usually quick and vigorous as the fermentation temperatures are not particularly cool. The vast majority of the sugar is fermented within the first seven days. This is followed by the slow phase of fermentation during which the last of the sugar is fermented. This usually takes a couple of weeks.
Malolactic conversion is prevented as acidity is typically already low and buttery flavours are not wanted. It is usually avoided by chilling the must; for biologically aged wines, using SO2 to prevent MLF would negatively impact the development of flor yeast.
After fermentation each batch of base wine will be tasted and sent for analysis. This is known as the First Classification and it decides whether the batch will be used for biological ageing (lighter-bodied, less intensely flavoured wines) or oxidative ageing (fuller-bodied, more intense wines). Those wines destined for biological ageing will be fortified to 15–15.5% abv, the optimum concentration of alcohol needed for flor yeast to grow. Wines destined for oxidative ageing will be fortified to 17% abv, at which flor yeast cannot survive. The liquid used to fortify the base wines is 95% abv grape spirit and therefore does not add its own aroma and flavour characteristics to the wine.
After fortification the wines are now in a stage called sobretablas where they are stored before joining the solera system. These wines may remain in tanks or be transferred to wooden barrels. After a number of months, the wines that were marked out for biological ageing at the First Classification will be tasted and analysed in the Second Classification. Wines that have a full layer of flor and have remained fresh will be classified as potential Fino or Manzanilla. Those that are slightly less delicate may be marked as potential Amontillado, and those that are even more full-bodied and intensely flavoured may be marked as potential Palo Cortado. The wines will then enter the solera systems.
Explain the maturation process for Sherry?
The maturation of wines labelled DO Jerez-Xérès-Sherry must take place in one of the three municipalities of Jerez de la Frontera, El Puerto de Santa María and Sanlúcar de Barrameda, together called the Zona de Crianza. (There is one exception to this rule; Moscatel can also be matured in the municipalities of Chipiona and Chiclana de Frontera.) The maturation process for DO Manzanilla – Sanlúcar de Barrameda must take place in the municipality of Sanlúcar de Barrameda.
The maturation of Sherry takes place in old wooden vessels. The vessels in any one bodega may range in size, however the most widely used is the 600L butt. The vessels tend to be made of American oak, primarily for historical reasons (American oak was brought back to Spain during the Spanish conquests), but it also has the benefit of being cheaper than French oak. The vessels are very old so are not used to contribute oak flavours.
The architecture of many of the bodegas is purposefully designed to create and maintain optimum conditions during maturation without need for modern air conditioning systems. The traditional bodegas have thick walls helping to keep temperatures constant. They are also generally tall buildings with high ceilings meaning that warm air rises away from the rows of butts, which are only stacked three or four butts high. These tall buildings also have small windows positioned high up near the roof. The windows are orientated to allow cool, damp south westerly winds from the Atlantic to enter, helping to lower temperatures and raise humidity levels. The windows have thin blinds to diffuse sunlight and prevent dust and insects entering. The floors are often made of earth and this can be regularly wetted during the summer to help lower temperatures and increase humidity.
The temperature and humidity in the bodega are especially important for growth and maintenance of flor, as part of biological ageing. Despite the effective design of the bodegas, there is still some fluctuation in conditions between summer and winter, and therefore growth of flor can often not be maintained throughout the year (though see Fino and Manzanilla in Styles of Sherry).
Explain the Solera System?
Most Sherry is a non-vintage product, and the solera system is a method of fractional blending that is used to maintain consistency and quality year after year. The barrels of wines that make up the solera system are grouped in sections known as criadera. The barrels belonging to the same criadera contain wine of the same age, and of a different age to barrels in other criaderas. The criaderas are named according to the relative age of wine that they contain. The criadera of the oldest wine is called the solera. The criadera with the next oldest wine is called the 1st criadera. The 2nd criadera has younger wine than the 1st criadera, and the 3rd criadera has younger wine than the 2nd criadera, and so on. Each criadera’s barrels will be stacked together in an area of the bodega.
The key rule is that no more than 40 per cent of the wine from one solera system can be removed for blending and bottling each calendar year, and hence the solera system always retains most of its wine. A further rule is that any wine that is released and bottled for sale must be a minimum of two years old.
The basic process is as follows:
- A proportion of wine (up to 40 per cent) is taken from each barrel in the solera (oldest group of barrels).
- The same proportion of wine is taken from the barrels in the 1st criadera, blended in a tank to ensure consistency, and then used to top up the barrels in the solera. Hence the younger wines from the 1st criadera are blended with the older wines from the solera.
- The same proportion of wine is taken from the barrels in the 2nd criadera, blended in a tank, and then used to top up the barrels in the 1st criadera.
- This process is repeated for each criadera, and the barrels in the youngest criadera are topped up with wines from the sobretablas.
In reality, wines can be removed early from the solera system for bottling before they reach the solera. This will be done for reasons of both style and, given the expense of having wine tied up in maturation, price. For example, an inexpensive Fino may be made from relatively young wines from, for example, the 4th and 5th criaderas, perhaps with a small proportion of 1st criadera wine to give some complexity. By comparison, a mid-priced or premium Fino may be made with a greater proportion of wine from the solera and 1st criadera for their complexity, with some younger wine from the 4th or 5th criadera to give a hint of freshness.
Wines from one solera system can also be blended with the wines of a different solera system during final blending, or some of the wine from one solera system can be fed into a different solera system for further maturation. For example, the wine for an Amontillado may undergo 5 years in a Fino solera system and then 8 years in an Amontillado solera system.
Explain biological ageing?
Biological ageing refers to the practice of maturing wine under a layer of flor. Flor is comprised of four strains of Saccharomyces cerevisiae. These yeast strains are found on the skins of the grapes from the Jerez region (they are also present in the bodegas where the Sherry is matured) and under the correct conditions, a layer of the yeasts naturally forms on the surface of the young wine. The wine needs to be a maximum of 15.5% abv (flor yeast consume alcohol, but struggle to survive in alcoholic conditions above 16% abv.). It is also important not to add SO2 to the wine as otherwise flor will be inhibited. Flor also needs plentiful oxygen, therefore Sherry butts are left 85–90 per cent full and the bungs are loosely inserted to ensure the flor is in contact with oxygen in the headspace of the barrel. The warehouse in which the wine is stored will need to have temperatures between 16–20°C (61–68°F) and humidity levels above 65 per cent.
The layer of flor has a number of influences on the wine. First, it protects the wine from oxidation, and hence these wines remain pale lemon in colour. Second, the flor consumes alcohol in the wine and releases acetaldehyde, which gives aromas that can be described as apple (often apple skin or bruised apple), hay and/or chamomile and sometimes a slightly bitter taste. It also consumes glycerol which gives the matured wine a lighter body. Glycerol also has a slightly sweet taste, and the reduction in glycerol can contribute to the very dry nature of biologically aged Sherries. Flor also reduces the levels of acetic acid.
The nature of the flor (i.e. the prevalence of each of the four yeast strains) changes in the different areas of the region, from bodega to bodega and even over the different stages of the solera system. This can influence the amount of alcohol consumed and the amount of acetaldehyde produced.
Over time in barrel, the flor yeast reproduces and dies. The dead yeast cells fall to the bottom of the barrel and autolysis takes place. This can lead to savoury, nutty flavours and enhances the texture of the wine. Various other aroma compounds form during the biological ageing process due to the reactions between alcohols, acids and acetaldehyde.
As well as maintaining style and quality, the solera system for biologically aged wines has another function. The young wine from the sobretablas is rich in nutrients for the flor such as alcohol, glycerol and acetic acid. As the wine matures under flor, these compounds are used up. The blending of younger wines into older wines therefore helps refresh the nutrient levels in older wines, keeping a thick layer of flor alive, which continues to protect the wine from oxidation. Partly for this reason, in Fino and Manzanilla solera systems smaller proportions of wine tend to be removed more frequently throughout the year. Another benefit of removing and bottling small volumes of wine more frequently is that the wine should be fresher when it reaches the point of sale (rather than having bottled stock sitting in a warehouse over the course of a year). This is important as these wines do not improve with bottle ageing and should be consumed as fresh as possible.
Explain oxidative ageing?
Oxidative ageing has a very different influence from the biological ageing process. The colour of the wines gradually changes away from lemon to gold, amber and then brown. Levels of alcohol increase slightly with ageing as, in the environment of the bodega, water is generally lost from the barrel at a quicker rate than ethanol; it is estimated that 3–5 per cent of volume is lost each year. (Some evaporation also occurs during biological ageing, but the consumption of alcohol by flor is more significant, meaning alcohol levels decrease.) This also means that other components of the wine become more concentrated. Glycerol levels rise and this gives wines that have been oxidatively aged a fuller, rounder body than those that have been biologically aged. Aroma and flavour compounds increase in concentration and evolve from primary characteristics to tertiary, oxidative characteristics such as caramel and nuts. During oxidative ageing, acetaldehyde decreases slightly, but levels of acetic acid and ethyl acetate (associated with volatile acidity) increase slightly.
Tell us about Sherry finishing and packaging?
Most Sherries are tartrate stabilised (often by contact process), fined and filtered prior to bottling. Filtration is particularly necessary in biologically aged Sherries to remove flor yeast. Otherwise flor could start to develop once the bottle is opened and the wine is in contact with oxygen.
Closures can be driven cork, cork stoppers or screw cap. All Sherries must be packaged and sealed within the three Sherry towns.
What does it take to be labelled one of the styles of Sherry
To be labelled as one of the styles below, the wines must conform to certain attributes as set by the Consejo Regulador. These attributes include the level of residual sugar, typical alcohol level, colour and other characteristics that are in line with how the wine has been matured.
Dry Sherries must have a maximum of 5 g/L of residual sugar.
Explain Fino’s and Manzanilla’s?
Both of these styles of wine must have spent their entire ageing process under a film of flor (biological ageing). They are pale lemon in colour and on the palate, dry, light to medium bodied, with low acidity and low alcohol of 15–15.5% abv. Their aromas and flavours depend on the length of time they have spent in the solera but may include aromas associated with acetaldehyde rather than primary fruit, bread dough and almonds. The wines range from good to outstanding in quality, and are inexpensive to premium or even super-premium.
Wines that are matured in the coastal municipality of Sanlúcar de Barrameda qualify as Manzanilla de Sanlúcar de Barrameda. Its proximity to the Atlantic, and hence its maritime climate, means that it does not have such extreme summers and winters and that humidity
is relatively high. These conditions are ideal for flor growth, and it is often observed that solera systems in Sanlúcar de Barrameda have thicker layers of flor than those in Jerez de la Frontera. It is also thought that while seasonal changes in temperature cause the flor to thin during the summer and winter in Jerez, the conditions in Sanlúcar de Barrameda are able to support thicker layers of flor around the year.
Although this may suggest that Manzanilla should have higher levels of acetaldehyde than Fino, this is not found to be the case. It is thought that differences in the flor strains between the two towns are a likely reason for this; the strain that has been shown to produce some of the highest levels of acetaldehyde is not present in flor samples taken from Sanlúcar de Barrameda. The greater protection from oxygen and lower levels of acetaldehyde mean that Manzanillas often taste lighter and fresher than Finos.
Given that Manzanilla solera systems have thicker levels of flor than Fino solera systems they need replenishing with young wines more frequently to support this growth. Hence small volumes of wine will be released and bottled several times throughout the year to ensure that the flor is constantly maintained.
Explain Manzanilla Pasada?
This labelling term describes a Manzanilla subjected to a short period of oxidative ageing. The flor may be left to die naturally by not refreshing the barrels with new wine for around a year. This wine may then enter a Manzanilla Pasada solera system. The wines are on average a couple of years older than Manzanilla wines, beyond which they start to become more like Amontillado.
