What is the cold stability method?

Answered by Jesse Garza

The cold stability method in winemaking refers to a process used to stabilize the by removing excess tartrates, which are natural compounds found in grapes. These tartrates can sometimes form crystals, also known as wine diamonds, when the wine is chilled. While these crystals are harmless and do not affect the quality or taste of the wine, they can be visually unappealing to consumers. Therefore, wineries often employ the cold stabilisation method to prevent the formation of these crystals.

Traditionally, cold stabilisation involves chilling the wine for an extended period, usually several weeks, in order to encourage the tartrates to crystallize. This process requires the wine to be kept at a temperature just above its freezing point, typically around 0 to -4 degrees Celsius. The low temperature causes the tartrates to slowly form crystals, which can then be easily removed through filtration or racking.

However, this traditional cold stabilisation method is not only time-consuming but also energy-intensive. It requires a significant amount of refrigeration to maintain the desired temperature for an extended period. This can result in high energy costs for wineries, which may not be sustainable or environmentally friendly in the long run.

To address these challenges, wineries have developed an alternative method known as the contact seeding process. This method involves the addition of seed crystals to the wine, which act as nucleation points for the tartrates to form crystals. By introducing these seed crystals, the winemaker can accelerate the cold stabilisation process and reduce the overall time required.

The seed crystals used in the contact seeding process are typically made of potassium bitartrate, also known as cream of tartar. These crystals are added to the wine before it is chilled, allowing them to dissolve and distribute throughout the liquid. When the wine is subsequently cooled, the seed crystals provide a surface for the tartrates to cling to, promoting the formation of larger crystals that can be more easily removed.

The contact seeding process offers several advantages over traditional cold stabilisation. Firstly, it significantly reduces the time required for the process, allowing wineries to achieve cold stability more quickly. This can be particularly beneficial for wineries that need to turn around their production quickly or have limited refrigeration capacity.

Secondly, the contact seeding process also reduces the energy consumption associated with cold stabilisation. By accelerating the crystallization process, wineries can decrease the duration of refrigeration, thus lowering their overall energy usage and costs.

It is important to note that while the contact seeding process is widely used and effective, it does require careful monitoring and control. The addition of seed crystals must be done in precise quantities to ensure proper cold stabilisation without causing any adverse effects on the wine's flavor or aroma. Winemakers need to have a thorough understanding of the process and make adjustments as necessary to achieve the desired results.

Cold stabilisation is a crucial step in winemaking to remove tartrate crystals and ensure visual clarity in the final product. While the traditional method involves chilling the wine for an extended period, wineries often opt for the contact seeding process to expedite the cold stabilisation process and reduce energy consumption. By adding seed crystals, winemakers can accelerate the formation of tartrate crystals, thus achieving cold stability more efficiently. However, it is essential to exercise caution and expertise when implementing the contact seeding process to maintain the wine's quality and integrity.