There are a few reasons why this may happen. Please see below:
1. Over-carbonation: Excess carbon dioxide can be produced if the beer ferments too long or at a high temperature, leading to increased pressure in the bottles.
2. Incomplete fermentation: Bottling too early may result in residual sugars fermenting in the bottle, increasing carbonation over time.
3. Contamination: Ongoing fermentation and excess gas production can be caused by wild yeast or bacteria.
4. Bottle conditioning time: Insufficient conditioning time can prevent CO2 from fully dissolving into the beer.
5. Agitation before opening: Moving or shaking the bottles just before opening can release CO2 from the solution rapidly.
6. Bottle filling technique: Too much headspace can cause uneven carbonation.
To mitigate this issue:
• Thoroughly chill the bottles before opening.
• Open the bottles slowly to gradually release pressure.
• For future batches, modify your recipe or process.
Identifying the precise problem can be difficult, but adhering to best practices is key:
1. Clean and sterilize all equipment.
2. Confirm fermentation completion with a hydrometer, ensuring stable gravity for 24-48 hours before bottling.
3. Use the proper amount of priming sugar.