Silicone plugs for wine barrels: advantages over other materials
In the wine production and ageing process, every element that comes into contact with the product influences its final quality, either directly or indirectly. Although much attention is paid to the barrel, the ageing system, or the type of wood, the barrel plug performs a critical function: ensuring proper closure, facilitating cellar operations, and protecting the wine from unwanted oxygen ingress and external contamination.
Why is the barrel plug key in wine ageing?
Oxidation, microbiological control, and process safety
- Controlled oxidation: poor sealing can lead to excessive oxygen ingress, premature oxidation, and loss of aromatic and colour stability.
- Microbiological control: the plug area can become a critical entry point for microorganisms (porosity, poor fit, contamination during handling).
- Operational safety: during racking and cellar movements, a stable plug reduces the risk of spills, losses, and process interruptions.
Most commonly used materials for barrel plugs
Wooden plugs
They are traditional due to their affinity with the barrel, but their performance is variable (porosity, moisture, swelling), with a more limited service life and more complex cleaning and sterilisation.
Conventional plastic plugs
They provide dimensional uniformity compared to wood, but may lose fit over time. Depending on the material and supplier, it is essential to verify their suitability for food contact and long-term stability.
Food-grade silicone plugs
Food-grade silicone stands out for its elasticity, chemical stability, and resistance to changes in temperature and humidity. When properly selected, it provides consistent sealing performance and reliable operation for repetitive winery processes.
Technical comparison: silicone vs wood vs plastic
| Criterion | Wood | Conventional plastic | Food-grade silicone (VMQ) |
|---|---|---|---|
| Sealing performance | Variable; depends on moisture and plug condition. | Good initially; may lose fit with use. | Very consistent; reliable sealing even after repeated use. |
| Organoleptic neutrality | May vary; porous material with potential interactions. | Depends on the polymer; food-grade suitability must be verified. | Generally inert; low risk of migration when food-grade. |
| Durability | Limited; degrades with moisture and handling. | Medium; may deform or fatigue over time. | High; resistant to deformation and ageing. |
| Cleaning and reuse | Difficult; porous structure and hard to disinfect. | Acceptable; wear with repeated washing. | Very good; suitable for long-term reuse. |
| Regulatory compliance | No specific certification. | Varies by supplier. | Available with FDA / BfR certifications. |
In which processes is silicone particularly recommended?
Ageing
Over long periods, silicone helps maintain stable sealing performance and reduces the risk of unwanted ingress.
Racking
When repeated opening and closing are required, its elasticity facilitates handling and maintains a reliable fit.
Controlled fermentations
In processes with variable conditions, a stable and resistant plug contributes to overall process safety.
When to choose silicone plugs for your winery
The Nortap food-grade silicone plugs are a robust solution for wineries and cooperages seeking consistency, hygiene, and durability.
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