As temperatures steadily rise across the globe, the knock on effect of climate change on viticulture is being felt by all wine producers. In the Cognac region it has been found that during the last 30 years, a 1°C increase in the maximum daytime temperature during the growing period of the vine has resulted in a 10 day advancement of the harvest. Whilst harvesting early has so far been successful, temperature increases also compromise the acid levels in the grapes (high acidity is essential for cognac production.) Longer term a different solution must be found so some of the big houses have got together to try and find one. Currently the majority of vineyards are planted with Ugni Blanc, a grape known for its high acidity levels, so a new grape variety, Monbadon, is now being trialled. Monbadon is known to have a higher level of acidity and lower level of alcohol than Ugni Blanc but it should have a similar aromatic profile and harvest later. Due to the ageing process of cognac, the overall experiment will take nine years but it is in 30 years’ time that the solution will be required, when global warming will have made a real impact. Hermitage Cognacs are hand selected to take advantage of careful harvesting and ageing processes used during their production.
Category: How to make Cognac
David on Technical Topics – The Cognac Wines
For many years, cognac quality has centred mainly on the distillation process and the basic needs of providing a relatively acidic and low alcohol wine. After the Phylloxera, in the late nineteenth century, viticulturists started to recognise the need to control the wine, harvest and production methods to a far higher level. The St Emillion (Ugni Blanc) grape, favoured for its resistance to disease and greater cropping, became the dominant variety and a key part of modern cognac wines.
The increasing demand on the industry for more cognac created further demands on the viticulturist to provide greater quantities of clean (low in sulphur dioxide), low alcohol wines for distillation. Regulations introduced in the 1930s banned the use of continuous wine presses that crushed the grapes since the additional pressure produced an undesirable stream of tannic and oily substances from the pips. In their place, modern rotating drum presses gently release the juices from the undesirable pips and skins.
Although climatically the Charente region is better suited to growing cognac vines than its surrounding regions, sun, rain and occasionally frost can have a severe effect on the wines produced. The Ugni Blanc matures late and is often not ready for harvesting until late October. In exceptionally cold conditions, when the grapes are picked cold, difficulties with fermentation occur creating a wine that is both thin and flat and which develops further difficulties in distillation. Perhaps a bigger problem with the weather, especially with more recent climatic changes, is the warmer autumns that create greater sugar levels in the grapes thus making a stronger and sweeter wine. The fully ripe Ugni Blanc grapes will produce a wine around 11 percent abv so the trick is to harvest just before they obtain maximum ripeness; an ideal strength is around 9 percent abv. The vintages of 1976 and 1989 are a case in point – wines often exceeded 11 percent abv making the fermentation too quick and the ethanol produced too great. This can create a cognac that is flabby and generally tasteless. Rain can also create problems especially in the summer when the grapes are filling out. The damp and warm conditions will allow fungus and rot in the tightly formed clusters so regular, preventative spraying is critical.
Even today wine making skills are still fairly basic. The wine is usually transferred into concrete, or in some more modern cases fibreglass lined metal tanks, for a quick malolactic fermentation. Special yeasts developed by the Station Viticole, the technical division of the BNIC, are used to encourage faster fermentation, a process that should take about six weeks. The longer the period of time between the fermentation and distillation the more the valuable esters that react with the tannins in the oak are lost. Many distillers will use the lees, in effect the pulp of the grape, to add further individuality and flavour to their distillations. A director of the Station Viticole once pointed out that it relies on nature, “We adapt our wine making skills to the needs of the still”. For all they are doing, he says, is preserving the interesting elements in the juice. The better the wines produced the greater opportunity there is to make the finest cognacs, like Hermitage.
David on Technical Topics – The Vines
The chalky soil of the Charente, particularly in the Champagnes, is not unique since it is also a notable feature of the Champagne growing region (it is the ‘Champenoise’ who stole the name for their famous drink). The chalk provides excellent drainage and can also store substantial quantities of water which the vine roots can easily access. Crucially too, chalky soil, which provides very few nutrients, improves the quality of the grapes.
Whilst the ‘terroir’ in the Cognac region can change, the grape varieties used have changed only twice in the last four centuries. In the 17th Century the region was largely planted with Balzac. It had some important characteristics in that it was a good cropping variety and didn’t bud too early which avoided any potential spring frosts. By the turn of the 19th Century the Folle, or Folle Blanche as we know it today, and to a lesser extent the Colombard, had largely replaced the Balzac. Both of these varieties had already been grown in the Armagnac region with considerable success.
By the mid-19th Century demand for cognac had grown considerably and there was increasing pressure on the vineyards to produce more wine. This increased demand had a detrimental effect on the vines as their roots weakened and they became susceptible to the tiny, yellow, louse, Phylloxera Vastatrix. The Phylloxera outbreak devastated European vineyards around 1870 – 1875 and most of the cognac vines died. It took twenty years before a new rootstock, principally grafted with an Italian grape variety, known as the Trebbiano Toscana from the hills of the Emilia Romagna, was imported from America. The grape became known locally as the St Emelion du Charente but is better known today as the Ugni Blanc. This green acidic grape, which produces a low alcohol wine with little character, is normally used as a base wine for blending.
After the Phylloxera the Cognaçaise started to plant their new vines in rows rather than the uneven bush planting methods used before. This new method of planting produced a greater concentration of vines per hectare and more recently has enabled the use of machines to pick the grapes. With careful pruning the vines, which grow on wires, can grow up to 1.8 metres high though are usually between 1.2 – 1.5 metres. The vines are still kept relatively low in order to take advantage of the reflection of the heat from the chalky soil. In some cases grapes at the top of a vine can take a week longer to ripen than those close to the ground.
Machine harvesting is now used in virtually every vineyard and has become well adapted to the modern methods of viniculture. Vine planting is controlled at a maximum of 3000 per hectare but this is a substantial number. Improvements in harvesting have increased the amount that a hectare can now produce. This was demonstrated a few years ago when the Chinese demand for cognac was high. As a consequence the BNIC changed the maximum permitted allowance to 10 hectolitres of pure alcohol per hectare (hl/ha) and many vineyards achieved this – only a few years earlier they had been struggling to produce 8.5 hl/ha.
However, as with all harvesting the weather is the biggest influencing factor. Whilst in most cases the Charente ‘terroir’ holds good, extremes of rain and sun can either delay the harvest or produce too much sweetness in the grapes creating a ‘pappiness’ in some cognacs. Cognac viniculture has come a long way in a relatively short period. If we can find Grande Champagne cognacs in 80 – 100 years’ time that were made in the last 20 years, they will be the true Siècle d’Or.
David on Technical Topics – ‘Terroir’, The Land
The French use the term ‘terroir’ uniquely to describe geological and climatic conditions as a basis for their system of ‘Appellations Cognac Controlee’. This is the geographic, quality control that defines the cognac crus and is vital for the Cognaçaise to differentiate their products. All the brandies entitled to the ‘cognac appellation’ are made from the same grape varieties, harvested in the same way, at the same time of the year, fermented in similar vats, distilled in the same type of still and aged in regulation oak barrels.
There are six crus of cognac and in the centre is the Premier cru de Cognac, Grande Champagne, from which most of the finest cognacs come. Most Hermitage Cognacs originate from here. Cognacs crus form concentric circles with Grande Champagne as a rough semi-circle in the heart. As you move further away from the centre, the cognac quality steadily decreases. Over time, cognac producers have gradually moved closer to the centre of the region.
In the west of the cognac region lie the islands of Ré and Oléron and the port of La Rochelle. Towards the east is the region of Limousin famous for its oak forests, the wood of which is used for the production of barrels used to age cognac. The landscape of the region is generally that of rolling hills, resembling the Sussex Downs, only with vines rather than pastures. This comparison is no accident since ‘cognac is a brandy of chalky soil’.
The heart of the Grande Champagne is composed of a special sort of chalk, the Campanian, a name which echoes the Latin origin of the word ‘Champagnes’. This pure chalk is found mainly on the higher elevations of the cru and is one of three layers of variously chalky soil which comes to the surface in the area. The other two layers are also rather special. Santonian chalk is named after the collective area of ‘Saintonge’ which covered much of Petite Champagne and Cognaçian chalk which surrounds the town of Cognac. The soil in Grande Champagne, like all other chalky soils was formed by the accumulation of small fossils including one found nowhere else called Ostrea Vesiculari. Fault lines made up of silica and marcasite also exist but it is the chalkiness in the soil which is crucial due to its physical properties, crumbliness and friability. The Santonian chalk is more solid and slightly less chalky but still quite crumbly and extends over some of the smaller slopes of Grande Champagne and Petite Champagne.
The Borderies cru, to the north of Grande Champagne, has special clay in the soil known as groies which dates geologically from the Jurassic era, some ten million years ago. It is a mixture of chalk, which is gradually breaking down and clay and produces a unique cognac with nutty and toffee qualities. Sometimes underrated this cognac is very different from the other crus. The surrounding crus of Fins Bois and Bon Bois are quite difficult to define, being a mixture of arable soil, compacted chalk and clay. They usually produce some unremarkable cognacs but there are a couple of exceptional areas. One is to the North East of Jarnac and the other is close to the Gironde estuary. Both have quite dense chalk and can produce some excellent cognacs. The sixth cru, Bois Ordinaire, makes little, if any cognac these days but it does supply eaux de vie for other purposes.
The climatic conditions over the area are usually regarded as temperate. Although snow is seen from time to time, very cold conditions are unusual and the extreme heat often experienced on the Mediterranean coast is rare. So it is in these rather special conditions, where vine roots can spread through the soil sometimes to a depth of more than twenty five metres, that the Cognaçaise can claim uniqueness, unmatched by any other part of the world. They are the perfect conditions for ‘Appellation Cognac Contrôlée’.
To read more Technical Topics go to our Brandy Education page.
David on Technical Topics – Cognac Distillation, The Wine Reduction
Cognac Distillation – The Wine Reduction
In the 16th and 17th centuries, the brandies produced in the Charente were reduced by distillation as this made them easier to ship abroad. The risk of low alcohol wines going off before they reached their destination was avoided and the intention was to cut them back with water before they were consumed. But the Cognaçaise soon found that keeping the strong wines in barrels changed them for the better and so they started to learn the skills of distillation.
The basic concept of distillation is that you boil the wines, collect the vapours that escape and then allow them to condense back into a liquid. It sounds ridiculously simple but there are many things that can go wrong unless the process is carefully controlled.
Cognacs are double distilled, that is to say that after the first distillation the wines are re-introduced into the still to be distilled a second time. During the process most of the chemical changes in the wine occur, at a temperature of less than 40 degrees, during the first distillation. Careful consideration must therefore be given as to that which is put into the still. Most modern day cognac distillations include the lees; this is anything but the juice. Most lees used consist of the pulp of the grape. In some cases the skin is also added but the pips and stalks are not as they will introduce an unacceptable bitterness. Some purists will filter out the lees and distil just the juice but this provides a cognac with less flavour and ultimate complexity. It is the yeast in the wine that contains esters which enrich the cognac and provide more flavour.
The first distillation is regarded by many as the most important as this is when the essential qualities of the fruit are extracted. The slower the cooking the more thoroughly the flavour in the wine is absorbed into the resulting brouilli (a cloudy and non-descript liquid at a strength of between 28 – 32 degrees). The brouillis is undrinkable and it is quite impossible at this stage for the distiller to determine the qualities of the final liquid.
The second distillation is known as the Bon Chauffe (good heating). Not all the newly distilled liquid or eau de vie is used. The first quantity, of around half a percent, is known as “the heads” and is discarded as it is too strong and will probably clog with some of the solids. The last part of the distillation, “the tails”, will be too weak. They can be re-introduced into the still but this is in itself a major decision. If the tails are used they will be distilled twice more and will create a level of neutrality in the final spirit. The middle part, which is probably greater than 95%, will be stored in new barrels for a few months to provide the new spirit with an initial boost of flavour and colour. The distillation range of the second boiling must be between 67 – 72.4 degrees, above this range the spirit will be burnt and below it there will be insufficient refinement in the final cognac.
To read more Technical Topics go to our Brandy Education page.
David on Technical Topics – Cognac Distillation, The Still
The cognac distillation process is the most technical part of making the golden nectar. It is the stage where the wine is reduced to a spirit, which we refer to as ‘eau de vie’. Distillation is carried out twice. The first time it changes the wine to a ‘brouillis’, a cloudy liquid with a strength of around 27 – 30% alcohol, and then it is distilled again. In this article we will consider the distillation equipment required and next month we will explore the process.
The complete distillation process is controlled by the Bureau National Interprofessionel du Cognac (BNIC) and every distiller must comply with the rules that protect the name of ‘Cognac’. The process usually starts at the end of October once the grapes have fermented and changed into a relatively low alcohol, acidic wine.
The bulbous, onion shaped, original design of the cognac still is largely accredited to the Dutch in the seventeenth century and has not changed significantly since. Sitting on top of this still is the chapiteau or still head. This is where the vapour rises after boiling and before continuing into the swan’s neck, an appropriately named pipe extending from the top of the still head. Eventually the vapour enters the serpentin, a large coil in a water tank, where it condenses before entering a tank ready for the second distillation.
Different still designs can influence the cognac’s final flavour. Firstly the size of the still is important. The smaller the still the more distinctive the cognac it produces whereas larger stills tend to provide more neutral flavours. The problem of neutrality is also created by the shape of the still head. Large, wide onion shaped stills allow the vapour to drip back into the still, a process known as rectification, and so the spirit is re-distilled. Conversely, narrow, shallot shaped heads allow the vapour to leave the still faster, with less risk of it condensing, before it has rounded the swan’s neck.
The other choice distillers must make is whether or not to use a chauffe-vin , a type of heat exchanger which sits between the still and the serpentin (condenser). This enables the warmth of the hot vapour to warm the wine before it enters the still for boiling whilst the initial temperature of the wine cools the vapours to initiate condensation.
Next month I will look at the Distillation Process. To read more Technical Topics, go to our Brandy Education page.
David on Technical Topics – Adding Water to Cognac
We call it dilution in the industry and nearly every cognac needs to have a level of dilution to optimise its qualities. Some cognacs are superbly smooth and almost too easy to drink whilst others are fiery and aggressive and seem to burn the mouth with every mouthful drunk. Getting the optimum balance between aggressiveness and flavour is a skill that must be acquired in order to maximise the quality of the cognac.
Adding water to cognac is certainly not just a case of pouring water from the tap into a barrel of cognac. The water must be pure and not contain any minerals. Distilled water is the normal choice but there are some special waters supplied in bulk for big blenders. The addition of this special water is a skill that has been developed over many years of understanding the noble spirit. In essence, spirit and water do not mix easily and some cognacs have a higher absorption level than others. A good diluter can taste the water in cognac if it has not been mixed properly. There are a number of ways that mixing can be undertaken.
Some producers dilute their cognacs whilst they are still hot and fresh from the still but this can be difficult as the strength of the cognac gradually reduces from the start of the distillation to the cut (the point where one stops collecting the water-clear eau de vie because it is too weak to provide sufficient flavour). Other producers will make a “Petite Eau”, a weak blend of cognac and water which is aged in casks before adding back into the cognac to arrive at the right strength. When a cognac has been produced and aged for many years most will dilute it gradually, a couple of degrees at a time. Each step can take many weeks before the correct balance is achieved and usually, the nearer one gets to 40% abv, the longer each step will take.
The speed of dilution depends largely on the speed that the cognac will absorb the water. A good dilution, where the two components mix without detection, may take several years. Other factors which may influence the dilution process are the size and shape of the still, the maximum temperature of the hot eau de vie and even the age, toasting and size of the barrels used for storage.
Cognacs should be diluted to a strength that optimises their flavour and so the final abv will vary. Take a look at our Hermitage 1975 at 47% and Hermitage 2005 at 40%, both of which are beautifully balanced and full of flavour.
You have probably gathered by now that adding a drop of tap water before drinking your cognac is not a good idea! Go to our Brandy Education Page to read more Technical Topics.
David on Technical Topics – Is there a need to Blend Cognac?
There are between four and five thousand cognac producers in the Charente and Charente Maritime region of France. Only brandy produced here, under strict regulations, is allowed to be called cognac.
The world market for cognac is hundreds of millions of bottles but because cognac can only be made once a year, after the grape harvest, the amount that can be sold is limited to how much can be made. The situation is made yet more difficult as even the very youngest cognac has to be aged for 3 years in oak barrels before it can be sold. The big cognac houses supply over 80% of world sales but probably only have direct involvement in about 5% of production. They rely heavily on the thousands of individual producers to provide enough cognac for their markets. Blending them provides consistent flavour and is therefore critical to their survival.
The big cognac names try to assert their authority over the smaller producers, by influencing their distillation methods, with varying levels of success. By blending hundreds, or indeed thousands, of different cognacs together any of the individual craft and style, which has been developed over the generations of distillation, is lost and the flavour becomes neutral. Indeed neutrality is encouraged by the major blenders since it is easier to blend neutral spirits than those with complex flavours. There is though, another factor that changes flavour and that is ageing. By buying their cognacs young and ageing them in their own cellars, the big houses are able to control any variation in style and flavour that may occur.
Most of the young cognacs sold to the major blenders will be at near distillation strength (67-72%); reduction in strength is therefore necessary. To enable this distilled water is gradually added, a slow process that can take many years to perform successfully. Additionally, because these cognacs are so young they will not have developed much colour or taste from the barrels and worst still, they will be aggressive and very fiery. All these problems can only be addressed with the permitted addition of sugar syrups and caramel.
The blending process should take years but to meet market demand it is often accelerated. Blending also fails to promote individuality in the final product. As a consequence, Hermitage Single Estate Cognacs, with age statements, offer a wide variety of styles, flavours and individuality with which blended cognacs cannot compete.
Read more Technical Topics on our Brandy Education Page.
David on Technical Topics – The Colour of Cognac Part 2.
Last month I discussed the effect of the natural ageing process on cognac colour but not all cognacs on the shelf have obtained their colour this way. Some of the big cognac houses try to provide a false maturity to their cognacs by adding a colouring agent. Most common of these colour additives is caramel and even quite small additions can make a relatively large difference since its use is usually in relatively young spirit that has only been aged for perhaps 2-3 years.
Previously I discussed how different types, sizes and toasting of oak barrels all make a difference to the colour of the cognac but colouring in this natural way takes a long time and many of the big cognac houses cannot wait long enough for this to occur. Much of the spirit they sell is young and so to give it more of a cognac-like appearance, caramel is added. Usually when caramel is used sugar syrup is also added to obscure the fiery flavour of the young cognac. Caramel can often be detected by sight as it will provide a red tinge to the spirit in the bottle.
A more natural way of colouring cognac, other than by the ageing process, is with the addition of ‘boise’. It is made by boiling oak chips in cognac over and over again to produce a dark syrupy liquid and this is then added to the cognac. Although this is a much more natural method of providing colour it can also give the cognac a slightly bitter flavour. Over time this bitterness disappears and the result is a more intense flavour and richness but its use has to be carefully controlled to achieve this effect. When ‘boise’ is used correctly, the appearance of the cognac remains natural and it can, we believe, enhance the flavour and long term stability of some very old cognacs.
All of the cognacs we supply at Hermitage Cognacs are aged naturally so the colours have not been altered with the addition of caramel. For example, the Hermitage Chez Richon 1979 Cognac has been aged for 25 years but still retains a relatively light colour.
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David on Technical Topics – The Colour of Cognac Part 1.
There is a long held view amongst cognac drinkers that the darker a cognac appears the longer it has been aged in the barrel and therefore the better and more valuable it is. There is, up to a point, some truth in this view since during the natural ageing process, the tannins in the wood add colour to the barrels’ contents.
Cognacs are aged in barrels made from one of two types of French oak, Limousin or Tronçais. The former comes from the Limousin forests north east of Angouleme and is a fairly wide grain oak whilst the latter, which is a closer grained wood, comes from near the Burgundy area of France. Clearly the wider grain oak allows greater penetration of the spirit into the wood and so enables a faster maturation. For this reason the Limousin oak is the most commonly used.
Prior to use the oak barrels are toasted to remove any harmful tannins. This can be done at different levels varying from quite light to heavy toasting. The heavier a barrel is toasted the darker the cognac will be but as a consequence, it will have more bitterness to its flavour and this can take many years to disappear. Most cognacs are kept in new barrels for a short period immediately after distillation before being transferred to old barrels where colouring occurs more slowly. Barrel size also influences cognac colour since the smaller the barrel, the greater the surface area that can come into contact with the cognac.
The colour of cognac is a very technical subject but one thing is certain, colour is not necessarily an indicator of age. Indeed we have some cognacs that have been stored in oak barrels for sixty or seventy years and retained a light colour. A wonderful example is our Hermitage Réaux 65 Year Old.
Next month I will discuss how the colour can be altered artificially in order to create a false image.
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