The shortest wine making instructions of a quality wine could be. Harvest as healthy grapes as possible and fast deliver them to the wine cellar.
Unfortunately, the conditions mentioned above are often not possible due to force majeure: diseases and pests that attack the vine, and natural disasters (hail, cold, drought, rain). Atmospheric and underground pollution can also cause chlorosis, drying of stalks, and shedding of strawberries due to a lack of nutrients. Often, the distance of the vineyard from the cellar is the cause of the spoilage of grapes.
Poor ripening of grapes in cold vintages means little sugar, dyes, tannins, and too much acid. But also the other extreme, high summer temperatures, with the consequence of forced ripening of grapes, decomposition of varietal aromas, and especially malic acid, also means a problem and a change in the quality and character of the wine.
Wine Making Instructions When Not Everything Is Ideal
All of these disasters can be mitigated if the winegrower and cellarman respond appropriately. Changes due to unhealthy grapes are manifested in the following forms:
- The abnormal structure of grapes and unusual chemical composition is usually due to fungal diseases that reduce the assimilation of green leaves.
- The imbalance between the liquid (strawberry juice) and hard (stalks, strawberry skin, pips) phase. The cause may be similar to the previous form, but in addition to fungal diseases, pests can also be the cause (juice part test).
- Degradation of certain components of grapes, especially fragrant, colored, and tannins.
The oenological profession agrees that this is the biggest disaster because there is no satisfactory solution. This is mainly due to the enzymatic action of laccase secreted by the fungus Botrytis cinerea in raw grape rot. This enzyme makes a mess in polyphenolic molecules. The consequences are damage to the paint – the intensity and liveliness of the paint are reduced – a bitter aftertaste and unpleasant odors (carbolic) develop.
What Can All Go Wrong?
In addition to problems with alcoholic fermentation, pesticide residues (dry autumn) can cause innocent tastes and unpleasant odors. Insecticides, acaricides, nematicides, and other pesticides used against pests do not interfere with alcoholic fermentation at normal doses, nor do they introduce innocent flavors or aromas, as pesticides are fixed in grape powder, and strawberry fat and migrate through wine to the human body, with all the consequences. In contrast, fungicides have a wider field of action to be a barrier to alcoholic fermentation.
Fungicides for botrytis are more significant potential inhibitors of alcoholic fermentation than other fungicides. How to prevent the negative consequences of damaged grapes? The enzyme laccase can only be destroyed by heating (temperature between 75 and 80 ° C). This procedure is expensive, and not all basements have the appropriate equipment. Raw grape rot is estimated to be harmful to red wines at levels above 12% and white wines at levels above 25%. The solution for very rotten red grapes is also the production of white wine from grapes of red varieties according to the production procedures of “blanc de noir” or rosé wines.