We have already discussed some of the faults that can occur in wine after it has been bottled. Read “ When to send wine back at a restaurant”,
Many problems can occur however throughout the duration of the winemaking process, starting from before the vines have beared any fruit. Let’s examine the barriers a vintner may come across in trying to grow healthy grapes.
Through over use or changes in its geological composition, soils can become depleted in certain nutrients that are requisite for growing healthy grapes. Chemical fertilizers can be key to replenishing the soils with their necessary nutrients.
Ideal weather is a variable, dependent on the variety of grape being grown and the place it is being grown. Cooler climates are ideal for growing grapes that are different from those that flourish in warmer climates.
If the temperature drops too low once the flower buds have opened in the spring time, this could result in a much lower yield of fruit for that year. If any extreme temperatures, excessive rain, or hail occur at this time, the flowering can be severely disrupted, or the vines can become damaged. Any of these factors can lead to a lower crop yield for that season. Once the fruit has beared, drought can threaten their ripening. On the other hand, an excess of rain can dilute the grapes. This is especially compromising when this rain come down just prior to the harvest. Humidity early in the season can be extremely threatening to the crop as it can cause a mould by the name of Botrytis cinerea to attack the grapes while they are immature. Also known as “grey rot” this mould multiplies rapidly, covers the grapes in a grey powder before they darken and eventually drop. There are certain circumstances however that instead of destroying the fruit, the Botrytis mould actually creates some of the world’s greatest sweet wines, like Sauternes. In this case, the “noble rot” causes the grapes to shrivel up, decrease in acidity and become highly concentrated in sugar.
But back to problems…
An infestation of pests may be detrimental to a vintner’s crop. Mites, caterpillars and most notably Phylloxera vastatrix can cause an extreme loss of crop or in some cases even cause a total destruction of the vines. Read “ The Great French Wine Blight” which was arguably the most devastating occurrence in the history of wine making. Most pests can be controlled with sulfur sprays and insecticides. In addition to this, the preventative method of planting a single rose bush at the end of each vine is commonly practiced. Mildew, pests, and fungi prefer the sweet smell of roses and so are drawn to them over the grape vines!