Home > Estudo, Projeto IMW > Projeto IMW – Prova de Admissão: Teoria

Projeto IMW – Prova de Admissão: Teoria

November 22nd, 2012 Rabiscaí! Checa os rabiscos.

Vimos antes que, como parte do pacotão inicial de inscrição no programa do Institute of Masters of Wine, é necessário fazer duas pequenas provas, uma prática e uma teórica. A parte teórica este ano foi, na verdade, retirada do exame de 2011: questões de prova eram apresentadas uma a uma semanalmente, para que os candidatos selecionassem a que preferissem para responder e enviar dentro de um prazo específico.

A questão escolhida deveria ser respondida “em condições de exame”, ou seja, com tempo marcado e sem consulta e ainda com limite de palavras. A maldade: assim que saia uma nova pergunta, o prazo da anterior vencia, então não dava pra arriscar demais pra ver se a próxima era mais segura. Abaixo, segue o texto que apresentei ao IMW, na íntegra e em inglês e, em seqüência, o “Examiner’s Report” do ano passado, que o instituto disponibiliza aos alunos e agora compõe a minha seleção de leituras semanais…

Drawing on examples of fortified wine production in different parts of the world, illustrate how production methods influence the style of the wine.

Fortification is the addition of alcohol to wine (generally, though not exclusively, distilled from wine or grape residues from fermentation) with various motivations, the most common and historically important being stabilizing it and determining its residual sugar content by interrupting the activity of fermentation yeasts and other microorganisms.

Laws regulating fortification change from region to region. Also, the amount of alcohol and the exact moment of fortification will vary according to the style of wine intended by the producer, even within a single region. In this essay, I will describe how fortification affects some of those styles in just a few of the regions where it is commonly adopted.

Jerez, in Spain’s south-western coast, is arguably the region with the widest range of styles of fortified wines. There, the amount of alcohol added to wines made from the Palomino Fino grape will determine whether flor, a naturally ocurring yeast that feeds from the wine itself after fermentation, will be able to set, thus defining the type of crianza, or ageing, and, ultimately, the style of these wines.

The flor is not able to develop under high levels of alcohol, so wines fortified (or encabezados, as the locals call it) to up to 16% will develop under flor, or crianza biologica, protected from the oxygen by the veil formed by those yeasts.

Those wines are generally classified as Finos, and are mostly pale gold or lemon in colour and marked both in aromas and flavour by the yeast and the by-product of its metabolism, the acetaldehydes, although further techniques or other influences (like ageing or yeast veil breaking down) may change the wines characteristics and classifications. Almonds, hazelnuts, fresh dough and flowers are common descriptors for these wines.

On the other hand, wines fortified to more than 16% – usually around 18% – won’t be able to develop the velo de flor (yeast veil) and will be exposed to the effects of oxidation, or crianza oxidativa. Those wines, generally classified as Olorosos, will be brown or amber in colour and will have their aromas and flavours marked by the oxidation: dried fruits, spices and roasted nuts are common descriptors for them.

The point of the winemaking chain of production at which the alcohol will be added will also influence the style of the finished wine, most commonly by defining its residual sugar, as in Porto wines from the Douro and on the Madeira island, the most famous regions in Portugal producing fortified wines. In Madeira, this is even more important than in Porto, since the wines are classified and categorized by their sugar content and perception of sweetness in the mouth.

Since the fermentation yeasts get “intoxicated” and are unable to work in presence of high-ish alcohol levels (generally somewhere between 16% and 18%), producers will decide when to add it to their wines based on how much sugar will the yeasts have consumed at the moment.

For example, wines made from Malvasia grapes, intended to become lusciously sweet and classified with the name of the grape as one of the most traditional styles of the island, will be fortified very early in the fermentation, in order to keep their residual sugar at at least 60 g/L. This also applies to wines made from Tinta Negra and other – generally regarded as lesser – varieties, intended to be classified as Full Rich or Doce, indications of the relative sweetness of the wines. Those will have to be fortified early enough to keep the residual sugars at around 100 g/L or more.

On the other hand, if the producer wants his wine to give a drier mouthfeel – like Sercial wines in Madeira or the very Finos from Jerez or Manzanilla from Sanlucar de Barrameda – they will let fermentation run its course and wait until the fermentation yeasts will have converted all or most of the sugar into alcohol before fortifying.

The fortification will also enhance the ability of the wine to develop through time: as with the fermentation yeasts, alcohol will also inhibit other microorganisms (such as bacteria and less useful, even harmful yeast strains) from spoiling the wine. Thus, the best fortified wines – such as Vintage Port, top quality Jerez Oloroso and aged, single variety Madeira – are amongst the longest-living ones in the world.

On the other hand, even simpler, fresher styles are able to resist time in bottle and even after opened, can keep their best characteristics for a longer time than non-fortified wines, especially those that have been deliberately oxidized during their fermentation or ageing: Tawny Port, Marsala, from the island of Sicily, in Italy and the many different wines made from Muscat (such as Muscat de Beaumes de Venise and Muscat de Rivesaltes in France) can be consumed in a few days or even weeks after opened.

Many regions in the New World produce fortified wines as well, most of them historically trying to emulate wines from the classical regions. Those wines are generally based in the Porto or Jerez styles and tend to follow the same precepts as these regions, although some of the “new” areas have been fortifying their wines for enough time to have developed a style of their own, either because of grape variety selection or a refinement of technique, as has happened in the Rutherglen area of Australia.

Fortification is, then, a technique born out of need of preventing spoilage of wines, especially when travelling long distances without proper storage, which developed into a very important winemaking style, with many different ways to influence the characteristics of the finished wine, mostly by interacting with the yeasts and allowing them to work in various ways. It is widely used throughout the world, producing wines virtually wherever there is a winemaking industry at work, but also making some of the most complex, interesting and long-lived wines there have ever been.

Examiner’s Report

Overall, a surprisingly disappointing response to what is a straightforward and uncomplicated question. A certain level of selectiveness was called for, as a full discussion of all styles and types of fortified wines is beyond the scope of the question. In such circumstances, it is always important to justify the choice of case studies or examples used. The stronger answers used well-chosen examples, contained accurate between the production method and the finished wine’s style.

Too often, though, answers contained technical inaccuracies, or revealed a serious lack of knowledge and understanding of this important group of wine styles. All examiners commented on the lack of basic knowledge on fortified wine styles and production methods, without which it would be impossible to respond successfully to this question. Some accounts made no mention of some of the better-known fortified wines such as Port and Sherry, and many inaccuracies marred some otherwise good accounts.

Good answers covered themes of grape variety, vinification timing and level of fortification, thus the level of residual sugar remaining and then varied approaches to maturation (including flor, oxidation, use of heat, etc.). Each had to be related back to the question and supported with examples but many candidates failed to do this; the tendency was to describe what happens, rather than analyse why.

  1. No comments yet.
  1. No trackbacks yet.