Wine Production and Quality

Keith Grainger, Hazel Tattersall

• Publisher: Wiley-Blackwell
• Year: 2015
• ISBN:
  9781118934579
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

Gourmand Award for the No. 1 Best Wine Book in the World for Professionals Since the publication of Wine Production: Vine to Bottle (2005) and Wine Quality: Tasting and Selection (2009), there has been a great deal of change in the wine industry, and the perceptions of critics and expectations of consumers have shifted. Wine Production and Quality, Second Edition brings together its two predecessors in one updated and considerably expanded volume.

This comprehensive guide explores the techniques of wine production in the vineyard and winery, and considers their impact upon the taste, style and quality of wine in the bottle. Part 1 of the book provides a structured yet easily readable understanding of wine production, from vine to bottle. The impact of natural factors, including climate and soil, is considered, together with the decisions made and work undertaken in the vineyard and winery. Part 2 looks at quality in wines: the concepts and techniques of tasting are detailed, along with the challenges in recognising and assessing quality. Also discussed are the steps producers may take, and the limitations they may face, in creating quality wines.

The book will prove valuable to beverage industry professionals, wine trade students, wine merchants, sommeliers, restaurateurs, and wine lovers as well as those entering (or thinking of entering) the highly competitive world of wine production.

PART 1
Introduction to Part 1 – Wine Production

No other beverage is discussed, adored or criticised in the same way as wine. To a few, it is something to be selected with the greatest of care, laid down until optimum maturity, carefully prepared for serving, ritually tasted in the company of like-minded people using a structured technique and then analysed in the manner of both the forensic scientist and literary critic. To many, it is simply the bottle bought in the supermarket according to the offer of the moment, drunk and perhaps enjoyed on the same day as purchased. To those favoured with living in wine-producing regions, it is often the beverage purchased from the local producers’ cooperative from a dispenser resembling a petrol pump, taken home in a 5- or 10-litre container and drunk with each and every meal.

There is a wonderful diversity in the styles and quality of wines produced throughout the world, promoting discussion and disagreement among wine lovers. The wines of individual producers, regions and countries rise and fall in popularity according to consumer, press and TV media perceptions of style, quality, fashion and value. Consumers do not remain loyal when they perceive that their needs and wants are better met elsewhere. If we consider the United Kingdom wine market, back in the 1980s, red wines from Bulgaria were very popular, and white German wines held the No. 1 position in the league table for white wine sales by volume. Australian wines were almost unheard of. By 2005, the wines of Australia held the top position in the UK wine market, by both volume and value of sales. In 2015, Australia still led the field in UK, although, in a market that suffered some decline over the previous 10 years, the volume of sales had slipped by 17%.

Few would dispute that the standard of wines made today is higher than at any time in the 8000 years or so of vinous history. The level of knowledge of producers, and thus the ability to control the processes in wine production, could only have been dreamt of even 40 years ago. Yet when, a few years ago, Decanter magazine compiled a list of the greatest wines of all time, the top position was awarded to Château Mouton-Rothschild 1945, and six of the ‘top 10’ wines were produced more than 40 years ago. Also, in the past few years, globalisation and consolidation of producers have perhaps had the detrimental effect of producing technically good wines whose styles have become standardised. In other words, the wonderful diversity we referred to is under threat.

In this part of the book, we detail how wine is produced, from vine to bottle. Many of the concepts are simple to grasp, others more complex. However, we need to stress at this stage that there is no single, unquestioned approach to wine production. Many procedures in common usage remain subject to challenge. Indeed, if you talk to 50 winemakers, you are likely to hear 100 different viewpoints, and many producers are constantly experimenting and changing techniques.

In considering wine production, there are two distinct stages: the growing of grapes (viticulture) and turning grapes into wine (vinification). Throughout the wine-producing world, there are many in the industry who carry out just one of these stages. There are growers who make no wine but sell their grapes to a wine-producing firm, or who are members of a cooperative that will make the wine. There are also wine producers who have no vineyards, or insufficient vineyards to supply their grape needs and consequently buy grapes from growers small or large. The decisions made and operations undertaken in both the vineyard and winery will affect the style and quality of the finished wine. These decisions will be based on numerous factors: geographical, geological, historical, legal, financial and commercial. The resources and availability and cost of local labour will have a major impact upon the decisions made and the structure of the wine-production operation. Both the grower and the winemaker are aiming for maximum control: yield, quality, style and cost. Of course, the aim is to make a profit.

Grapes contain all that is basically necessary to make wine: the pulp is rich in sugar, and yeasts are present in the bloom on the skins. These yeasts also migrate onto winery surfaces and may initiate a spontaneous fermentation of the sugar rich must. Must may be defined as grape juice and solids prior to fermentation. However, many winemakers choose to inhibit these natural yeasts and use cultured yeasts for fermentations. It should be noted that, unlike in the production of beer (and many spirits), water is not generally used as an ingredient in winemaking. The grapes should be freshly gathered, and ideally the winemaking should take place in the district of origin. However, this is not always adhered to, particularly with regard to inexpensive wines. It is not uncommon for grapes or grape must to travel from one region to another, or sometimes even to another country, prior to fermentation.

Wine is, of course, alcoholic. The alcohol in wine is ethanol, otherwise known as ethyl alcohol. Although it is a natural product, ethanol is toxic and can damage the body if taken in excess. The alcohol is obtained from the fermentation of must by the action of enzymes of yeast that convert the grape sugars into ethanol and carbon dioxide. Although the fermentation lies at the heart of winemaking, every other operation will impact upon the finished wine. The entire production process may take as little as a few weeks for inexpensive wines, or two years or more for some of the highest-quality wines. In the case of some fortified wines, the production process may take over a decade.

Throughout this book we will usually refer to the area measurement of land in hectares, which is the most used term in member states of the European Union, although the United Kingdom prefers to measure in acres. A hectare is 2.47 acres, some 10,000 square metres of land. Units of liquid measure are expressed in litres (l) and hectolitres (hl) – there are 100 litres in a hectolitre. Units of weight will be stated in grams (g), kilograms (kg) and metric tonnes, i.e. 1000 kg.

The methods and techniques explained in this part of the book include some that have been recently introduced by forward-thinking producers. There is a constant strive for improvement at all levels in the industry. As South African winemaker Beyers Truter says: ‘If you ask me: “Have you made the best wine, or the best wine that you can?” and I answer “Yes”, then you must take me away and bury me.’

CHAPTER 1
Viticulture – the basics

The aim of the grape grower is, following a successful annual vineyard cycle, to harvest ripe and healthy grapes, of the quality and to the specification required for subsequent vinification. The grower and winemaker are both aware that any deficiencies in the quality of the fruit will affect not only the quality of the wine but also profitability. In this chapter, we will examine the grape vine and its fruit in some detail. We also look at the reasons why vines are grafted onto rootstocks, including the devastating effect of the Phylloxera louse, and why crossings have been developed.

1.1 The grape vine

The cultivation of...