Biochemical changes throughout Grape Berry development and fruit and wine quality

Recently, I began reading this online freely available article called Biochemical changes throughout Grape Berry development and fruit and wine quality published in 2007. Although it is now a rather dated reference, it nevertheless contains some really good information that I am going to summarize, mainly for myself but hope that it is useful for you, too.

What is it about the grape that makes it an ideal fruit with which to make wine?

• a high concentration of sugars and other nutrients that provide a luxurious medium for the growth of wine yeasts
• a natural acidity, which is high enough to inhibit the growth of undesirable and noxious microorganisms during and after fermentation
• a high concentration of ethanol produced by sugar fermentation, which contributes to inhibit microbial activity in the product
• a unique presence of aromas and flavours

The grape contains all of these properties that can be transformed into a delicious liquid---wine. But, what does it take to make this liquid, the ultimate expression of the grape?
Viticulture

• wine quality largely depends on the vineyard and on the vine grower; the most important factor for viticulture is climate, and above all, temperature
• the French term “terroir” is used to refer to characteristics such as soil composition (minerals, soil density), sunlight, climate (temperature, precipitations), topography and “terroir” can also take into account strains of microorganisms usually found on the berry skin (the indigenous yeast and bacteria)
• the soil type depends on how the geological parent material has been altered and shaped by physical, chemical and bioglogical processes
• rainfall and drought also play an important part; it is almost impossible to grow wine with less than 200 mm (~8 inches) of rain a year
• moderate climate, with adequate to relatively high rainfall, provides ideal conditions for producing both fragrant white wines with good structure and acidity, and well-balanced red wines with good potential for maturing

The Grape

• most of the wine compounds are produced by the plant itself, in leaves (sugars and acids), and in berry (acids and phenolics)
• some molecules related to aroma and taste are produced during the fruit development and ripening; these aromas, called primary aromas are characteristic of the varietal

Reference:
1. Carlos Conde, Paulo Silva, Natacha Fontes, Alberto C. P. Dias, Rui M. Tavares, Maria J. Sousa, Alice Agasse, Serge Delrot, Hernâni Gerós, Biochemical changes throughout Grape Berry development and fruit and wine quality, Food, 1(1), 1-22 ©2007 Global Science Books.
2. Illustration from: Isak S. Pretorius, Conducting Wine Symphonics with the Aid of Yeast Genomics, Beverages, 2016, 2(4), 36.