Can You Make Wine with Rotten Grapes? Special Case | Noble Rot

While the idea of making wine with rotten grapes might seem appealing, it is generally not advisable due to the risks involved. However, there is a special case where the controlled use of Botrytis cinerea, also known as “noble rot”, can result in one of the most celebrated wines in the world. This article explores the nuances of using rotten grapes and introduces the concept of noble rot in winemaking.

General Considerations: Risks and Unwelcome Consequences

Using rotten grapes in wine production is generally not recommended. While some winemakers may use slightly overripe or damaged grapes for certain styles, significantly rotten grapes can introduce several undesirable elements:

Mold and Bacteria: Rotten grapes can harbor mold and harmful bacteria, which can spoil the fermentation process and lead to off-flavors. Flavor Profile: The flavors from rotten grapes are often unpleasant, resulting in a wine that tastes sour or vinegary. Fermentation Issues: The presence of rot can create problems during fermentation, leading to stuck fermentations or the production of undesirable byproducts.

In summary, while certain forms of rot can be used in specific wine styles, using severely rotten grapes is not recommended for quality wine production.

Introduction to Noble Rot: A Special Case

Not all rot is bad. In the case of Botrytis cinerea, known as noble rot, the fungus can be harnessed to create exceptional wines. Noble rot is a specific type of fungus that attacks the skin of the grape, making it porous and allowing the juice to evaporate. This process helps to concentrate the sugars and flavors, resulting in one of the most celebrated sweet wines in the world: Tokaji Aszu from Hungary.

The Process of Botrytis Cinerea

The process of botrytis cinerea involves several key steps:

Fungus Growth: The fungus begins to grow on the grape skins, causing them to become porous. Juice Evaporation: As the fungus attacks, some of the juice evaporates, concentrating the flavors and sugars. Harvest Timing: Winemakers carefully time the harvest to ensure the perfect moment when the grapes are just right for botrytis cinerea. Winemaking: The concentrated grapes are then used in the winemaking process, which often includes extended aging in oak barrels.

The result is a sweet wine with a balanced acidity, a honeyed flavor profile, and notes of ripe fruit like apricot, peach, and pear. More expensive and aged versions can have a stronger dried fruit flavor and notes of toffee and vanilla from the oak barrels.

Practical Considerations for Using Rotten Grapes

While noble rot is a controlled process that can produce exceptional wines, there are still risks when dealing with mold and rot. Here are a few practical considerations:

Mold Risk: A lot of mold can significantly increase the risk of a bad result. This is where careful monitoring and handling come into play. Controlled Environment: Using a smaller amount of mold on grapes, especially in a controlled environment, can still lead to a useful juice for certain wine styles. Metabisulfite Addition: To suppress any mold or wild bacteria, it is recommended to add at least the normal amount, and possibly more, of metabisulfite.

Always ensure that the grapes are properly cleaned and sanitized to minimize the risk of off-flavors and spoilage.