Coulure

Coulure is a viticultural hazard that is a result of metabolic reactions to weather conditions that causes a failure of grapes to develop after flowering. In viticulture, the consistency of annual yields is a primary concern for vineyard owners and winemakers.

Causes and Effects

Coulure is primarily caused by environmental factors such as cold, rainy or windy conditions during the flowering stage of the vines. It can also be influenced by vine nutrition and the vine's excessive vigour.

The condition often manifests after periods of cold, rainy weather during the flowering of the vine. The grapevine flowers may stay closed or not shed pollen efficiently leading to millerandage, or "hens and chicks", where the berries develop unevenly. This results in clusters of grapes with different sizes and ripeness levels, which can lead to lower wine quality.

Management

There are several methods to prevent or manage coulure. One of the most common methods is through the use of vine training and pruning techniques which can help to balance the vine’s vigour and increase its chances of successful pollination.

Another method is the use of certain fertilizers that can help to improve the vine's overall health and its ability to withstand the conditions that can lead to coulure.

Impact on Wine Production

Coulure can significantly impact wine production. When coulure occurs, the yield of grapes is reduced, which can lead to a reduced wine production. In addition to lower yields, the quality of the wine can also be affected. Grapes that are affected by coulure will often have higher acid levels and lower sugar levels, which can result in a wine that is less balanced and has a lower alcohol content.

See Also

• Viticulture
• Grapevine
• Wine production

‎

‎