Tutored Wine Tasting STICKIES Speaker: Eric LAGRE Sommelier INTRODUCTION: “SWEETNESS INTO WINE” Everybody likes sweet wines, but who has ever taken time to reflect on the often labour- intensive and painstaking task of making a wine sweet? The first question that crosses one’s mind when tasting a sparkling wine is always: “how do they manage to put bubbles into wine?” Sparkling wines strike even non-connoisseurs as technical wines. It seems obvious that a great deal of human ingenuity came into play when one decided to make and keep a wine sparkling. But was it that much of a challenge? As a matter of fact, the occurrence of the bubble is a natural phenomenon in cold climate wines. At a time when the fermentation process wasn’t fully understood, a second fermentation would be triggered by the exposure of these wines to warmer conditions or sugary additives. The eradication of the bubble in still light wines from the Champagne was actually what Dom Perignon was working so hard to achieving before he eventually gave in to the bubble and formalised the keeping of it in the bottle. As for sweet wines, grape juice is sweet, so how difficult can it be to make a wine sweet?! But are sweet wines as straight forward to produce as one thinks? Wine is the result of the fermentation of grape juice, the so-called must. When fermenting yeasts, present in the environment, enter into contact with the sugars in the must, they start metabolising them into alcohol, with heat and CO 2 as by-products, in an uncomplicated process that only takes a few days to complete. But when you consider that fresh grapes picked healthy, having just reached maturity, at which stage harvest is officially declared, yield juices the fermentation of which stops naturally once most sugars have been converted into alcohol and the yeasts have died by lack of nutrients to feed on, the question of sweet wines becomes a rather puzzling one. Despite being simply called “fermentation”, the process is always understood as “fermentation to dryness”. So, when you realise that the result of fermenting sweet grape juice is always dry, you are bound to ask: “how do they manage to put sweetness into wine?” DEFINITION OF WINE AND TERROIR: Before I come to the actual description of the various techniques used for achieving sweetness into wine, it is important to place sweet wines in the context of the official definitions of wine and terroir . Wine is a fruit of the vine and the vine springs from its terroir. The French INAO (Institut National des Appellations d’Origine) gives the academic definition of terroir : “Terroir is the conjunction of soil, climate and man” . The definition is actually more precise, as various types of soils, climates and human experiences need considering. Soil is both pedological and geological. The pedological soil is that in which the vine grows its roots and finds nutrients, and the nature of the pedological soil evolves in relation to a climate (a source of water and light in an environment subject to temperature variations), life (altogether microbiological, vegetal and animal) and minerals (either present in the soil originally or added). The geological soil is the original mineral source, the actual solid earth, the bedrock on which the living soil builds up. Climate, which impacts on the vine’s vegetative growth, combines microclimate (climate at a precise geographical point) and vintage (climate at a precise moment in time). Eventually the wine will yield grapes, the quality of which reflects a given soil and climate, then the grapes will be turned into wine by man. The way man works the vine and its fruit responds to tradition (a savoir faire), but also to his drive as a winegrower and winemaker (his own talent and ingenuity). Without man, there is no terroir (and Michel Chapoutier, to whom an understanding and respect of the terroir is central to his winemaking philosophy, likes to remind us that mankind might also be the cause of its ruin). Dry still light wine invented itself, as man only had to reproduce the result of the fermentation of some grape juice accidently left aside, which he was curious enough to taste in the first place; so human! As for making sparkling wine, it was just a matter of harnessing and enhancing a natural phenomenon in wine. But when it comes to making a wine sweet, man had to invent new processes altogether, processes that were not but occasionally observable in nature for him to reproduce. Man, with his savoir faire and ingenuity, is the cornerstone of sweet winemaking. The same way as without man there is no terroir, without man there is no sweet wine either, and the concept of terroir seems to have been tailor-made for the description of sweet wines above all wines. As much as the concept of terroir fits sweet wines like a glove, the European definition of Wine does not. EU wine directives are very specific in their definition of Wine : “Wine is the alcoholic beverage obtained by the fermentation of the juice of freshly gathered grapes, the fermentation taking place in the district of origin according to local tradition and practice” . But what if sweet wine is made from grapes picked long before they are pressed or by not fermenting the must at all? PUTTING SWEETNESS INTO WINE: There are many techniques used around the world to produce sweet wines, each one impacting a great deal onto the aromatic makeup of the final product. In that sense, the world of sweet wines is a very exiting one to explore. In her “Oxford Companion to Wine”, Jancis Robinson tells us that “some wine drinkers have been conditioned to be suspicious of any sweetness in a wine, perhaps because neophytes generally prefer some residual sugar, and sweetness is therefore associated with a lack of sophistication”. Indeed, most wine consumers would tell you that they favour dryness, even though most of the big international brands that swamp our supermarket shelves have some sweetness added to them in the shape of processed unfermented grape juice. It is a shame that the modern taste for lower-alcohol, dry wines has made sweet wines rather unfashionable, for if you start on a journey of discovery, you will realise that sweet wines come in a great variety of styles and gladly experience the huge spectrum of their aromas and flavours. Every method used for the production of sweet wines stems from some understanding of the fermentation process. In order to make a wine sweet, one must prevent the fermentation process from completing its course by using many different techniques... and sweet wines are highly technical wines indeed! WINERY WINE: Sweetness can artificially be put into wine in the winery. For a start, one can interrupt the fermentation process by simply refrigerating the must. Bear in mind that that type of sweet wine cannot be put on the market without further treatment, for as soon as it gets warm, the wine starts fermenting again, turning the bottle into a gas bomb. The wine needs to be stabilised first. It is possible to produce stable sweet wines by taking the yeast out of the equation altogether, either by killing it by adding sulphur to the fermenting must, the result being not so stable and often unpalatable, or more effectively, by removing the yeast from the fermenting must through filtration. Surface/membrane filtration, best known a microfiltration, or sterile filtration, is how sweetness is kept in the sparkling Moscato d’Asti, for instance. But not many sweet wines are produced that way. The technique is more commonly used as the first step towards the production of sweeteners that will then be added to a dry wine base to turn it sweet. There are three types of sweeteners: Sweet Reserve (or Süssreserve as it is called in Germany), which is unfermented grape juice stabilised through filtration; Rectified Grape Must (RGM), a “Sweet Reserve” concentrate; and Rectified Concentrated Grape Must (RCGM), a grape concentrate further processed to remove water and yield grape sugar crystals, the so-called inverted sugar. Inverted sugar is the sugar one finds in the fruit itself, which is composed of glucose and fructose. Inverted sugar was first produced to industrial scale as a solution to overproduction in order to keep the big European wine lake in check. In the wine industry, inverted sugar has become the favoured alternative to sucrose, commonly known as plain sugar. Preserved grape juice, or Sweet Reserve, is made by refrigerating, filtering, clarifying then cold- stabilising unfermented grape must. Winemakers prefer preserved grape juice to any other type of sweetener, because it is the sweetener that resembles wine the most; it has the same water content as wine and is the natural, unadulterated base from which wine complexity can develop. But since RGM and RCGM are more concentrated and bacteriologically stable, therefore not needing refrigeration to keep, they are less bulky, hazardous and costly to store. Artificial concentration methods with such barbaric names as low-pressure/vacuum evaporation, reverse osmosis or cryoextraction are used in the making of grape concentrates (or more controversially to improve wine quality in Bordeaux, for instance). Such methods, especially when ion exchange is also used, can dramatically alter taste. Ultimately, RCGM, crystallised through the use of evaporation techniques, will be stripped of all complexity and taste of nothing but sugar. In order to soften and counterbalance high and tart acidity rather than to make a wine sweet, such sweeteners can be blended to a dry wine base.