Unusual exposure to heat can affect the performance of sealed bottles in two main ways:

1. Pressure build-up inside the bottle: High ambient heat levels will increase pressure within the bottle, potentially causing the stopper to lift if not addressed in advance with the correct bottle and stopper design. Of primary importance is that the fill level is correct and that the head space — also called ullage, the empty space between the liquid and the stopper — is appropriate. The less head space, the more likely there is to be an issue. If it is expected that the bottle will be exposed to abnormally high temperatures, the stopper can be designed in such a way that aids in mitigating the issue.

2. Cap adhesion issues due to melting glue: When wood or plastic caps are glued onto cork or synthetic stoppers, high heat exposure can melt the adhesive typically used, causing the caps to detach. This can occur when bottles are sealed with extremely hot wax. To prevent this, an adhesive specifically designed for high-temperature resistance should be requested prior to stopper production.

If you have concerns about heat exposure in your specific bottling or storage conditions, please contact us early in your production process so we can ensure your stopper is specified correctly.