Do I need to burp the bottles during second fermentation to release pressure?

Question

Do you need to burp kombucha bottles during F2? Learn about the debate on burping, how it affects fizz, and how to safely manage pressure buildup.

Answer 1

Burping bottles during second fermentation is generally recommended to release excess CO2 pressure and prevent explosions, especially with fruit additions or higher sugar content. However, the frequency depends on factors like temperature, sugar levels, and bottle strength.

Detailed Explanation:

Second fermentation, often used in brewing beer, cider, or making kombucha, involves adding sugars or fruit to a fermented beverage in a sealed bottle. This process creates additional CO2 as the yeast consumes the added sugars. If the pressure builds up too much, the bottles can explode, creating a dangerous mess.

Here's a breakdown of why and how to burp bottles:

1. Why Burp: The primary reason is to release excess CO2 pressure. Without burping, the pressure can exceed the bottle's capacity, leading to explosions. This is especially important if you've added a significant amount of sugar or fruit, or if the fermentation temperature is higher, which accelerates CO2 production.
2. How to Burp: Carefully open the bottle slightly to release some of the pressure. Do this slowly and over a sink, as some liquid may escape. Once the hissing stops, you can re-seal the bottle.
3. Frequency: The frequency of burping depends on several factors. Start by burping once a day for the first few days, then reduce the frequency as the fermentation slows down. If you notice excessive pressure buildup (very hard bottles), burp more frequently. If there's little to no pressure, you may not need to burp at all.
4. Alternative: Using pressure-rated bottles designed for carbonation can reduce the risk of explosions. These bottles are thicker and stronger than standard bottles.

Pro Tip:

Use a fermentation calculator to estimate the amount of sugar needed for carbonation. Over-priming (adding too much sugar) is a common cause of bottle bombs.