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17 November 2022

How to extend carbonation shelf life by around 4 weeks

Posted in Sustainability

The seepage of CO2 from PET bottles reduces the shelf life of carbonated soft drinks (CSDs), which also means that only limited stocks can be built up ahead of periods of peak demand. CO2Sustain can significantly extend that carbonation shelf life, providing a more sustainable solution.

The vast majority of beverage formulations sold in PET bottles have a long shelf life, probably running into years. Unfortunately, the same cannot be said for the CO2 in those bottles, which has a significantly shorter shelf life before the CSD’s carbonation reduces to the point of unacceptability.

Overall, therefore, the typical CSD has a carbonation shelf life of between 3 and 4 months – a little longer in cold countries, and shorter in hot countries where the seepage will be faster.

Overcome production/logistical problems

This means that manufacturers are limited by how much of their beverage they can produce and store in advance – leading to production and logistical problems at times of peak demand (for example, during the summer or major celebrations). A failure to supply demand in any territory, or to any major retailer, could have a disastrous and lasting impact on market share. Conversely, any stock past its sell-by date will need to be returned to the manufacturer at the manufacturer’s cost; this creates unnecessary plastic and water waste from CSDs needing to be destroyed.

Consumer acceptability

We have already seen that CSDs in PET bottles require an additional 0.5g/litre, or 6.6%, purely to allow for loss through seepage. This loss reduces the CO2 content from 8g per litre at production to 7.5g per litre at the point of sale. When the consumer then opens and pours the drink, considerably more CO2 is lost through fobbing – taking the consumer’s CO2 experience down to about 6.2g/litre. This is the tipping point for most manufacturers, based on meticulous consumer testing: below that level, the beverage is considered unacceptable.

However, adding CO2Sustain can allow the CO2 to drop to 5.6g/litre with no discernible effect on the consumer experience. This saves 0.6g of CO2 per litre – and with a known loss of around 0.1g per week, this permits an additional 4 weeks of shelf time before the consumer would find the beverage unpalatable. Extending the current average 16-week shelf life to 20 weeks.

CO2Sustain benefits
  • Can extend CSD shelf life by around 4 weeks
  • Reduces the amount of CO2 required, which reduces transportation miles
  • Supports manufacturers in preparing for peak demand periods
  • Smooths production, leading to production energy savings
  • Supports retailers in storing stocks for longer
  • Reduces the transport of returns by retailers
  • Less waste goes to landfill
  • Less water is wasted
  • Certainty of supply protects relationships and agreements with retailers
  • Protects consumer relationships by delivering the optimum brand experience for longer.

To learn more about how CO2Sustain helps soft drinks manufacturers with a number of sustainability issue download our sustainability brochure here. If you would like to chat to us about how we can help extend your drinks carbonation shelf life then please call us on +44 (0)113 205 0971 or email

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