Isobaric bottling machine: how to solve the filling of carbonated beverages
What is an isobaric bottling machine and what problem does it solve
An isobaric bottling machine is a machine designed to carry out filling while maintaining a pressure balance between the product tank and the container. This principle makes it possible to prevent the release of carbon dioxide dissolved in the liquid during bottling.
Isobaric technology is essential for products such as:
- sparkling water
- carbonated beverages
- beer
- soft drinks
- sparkling and semi-sparkling wines
Without a controlled-pressure filling system, the product would undergo gas loss, resulting in foam formation, inaccurate fill levels, and deterioration of organoleptic characteristics.
The term isobaric bottling refers to a process also known as counter-pressure bottling. The literal meaning of “isobaric” is “at constant pressure”: during filling, the pressure inside the bottle is kept
equal to that of the product tank, avoiding any imbalance that could compromise liquid stability.
Isobaric bottling machines: how they work
The operation of a controlled-pressure bottling machine is based on a sequence of well-defined technical phases, designed to ensure process stability and repeatability.
- Evacuation of air from the container
- Pressurization of the bottle with gas (generally COâ‚‚)
- Filling at constant pressure
- Sealing of the container without gas loss
Throughout the entire cycle, the pressure inside the bottle is kept equal to that of the tank, preventing turbulence and product degassing.
A technical advantage of isobaric bottling is the almost total removal of oxygen present inside the container before filling. The air pre-evacuation phase, often repeated several times, makes it possible to drastically reduce residual oxygen content, improving product shelf life and limiting oxidation phenomena, which are particularly critical for beverages such as beer and soft drinks.
When an isobaric filler is necessary
The use of an isobaric bottling machine is not an optional choice, but a technical requirement in all cases where:
- the product contains dissolved COâ‚‚
- carbonation stability is required
- high production speeds are involved
- waste and rework need to be reduced
In these contexts, the use of alternative technologies would inevitably lead to quality and production efficiency issues.
Differences between isobaric bottling machines and gravity fillers
One of the most frequently asked questions concerns the difference between isobaric technology and gravity technology. The following table summarizes the main operational and application differences.
| Feature | Isobaric bottling machine | Gravity filler |
|---|---|---|
| Type of product | Carbonated and pressurized beverages | Non-carbonated beverages |
| Pressure management | Constant and controlled pressure | Atmospheric pressure |
| COâ‚‚ preservation | Total | Not guaranteed |
| Foam formation | Absent or minimal | Likely |
| Fill level accuracy | Very high | Medium |
| System complexity | High | Low |
| Plant cost | Higher | Lower |
| Typical applications | Sparkling water, beer, soft drinks, sparkling wines | Still water, still wine, juices, oils |
Foam formation during the bottling of a carbonated beverage is the direct consequence of a sudden pressure change. When the product moves from a pressurized environment to one at atmospheric pressure, the dissolved gas tends to expand rapidly, generating bubbles and foam. This phenomenon is accentuated by high temperatures and by the presence of proteins or sugars in the product. The isobaric bottling machine solves this problem by maintaining pressure control throughout all filling phases, minimizing degassing and ensuring a stable process even at high production speeds.
Main technical features
Modern isobaric bottling machines are equipped with advanced technological solutions that guarantee high performance and long-term reliability.
- high-precision isobaric filling valves
- electronic pressure control
- integration with rinsers and cappers
- compatibility with PET and glass bottles
- CIP systems for automatic sanitation
Each machine is configured according to the product, the required speed, and the operating conditions of the line.
Cost of an isobaric bottling machine
The cost of an isobaric bottling machine depends on several factors:
- number of filling valves
- production capacity (bottles/hour)
- level of automation
- new or refurbished used machine
Indicatively, prices start from around €80,000 for basic solutions and can exceed €300,000 for complete industrial lines.
Frequently asked questions
Is an isobaric bottling machine suitable for craft beer?
Yes, it is the ideal solution to preserve carbonation and reduce product oxidation.
Can it be integrated into an existing line?
Yes, subject to a technical analysis of the line and its mechanical and electronic interfaces.
Useful insights
BBM Packaging isobaric bottling machines
BBM Packaging offers a selection of isobaric and non-isobaric bottling machines, available in refurbished and guaranteed used versions, providing a concrete solution for those seeking economic competitiveness without sacrificing reliability. All machines are supplied ready for installation, tested and configurable according to line requirements, with the assurance of compatible spare parts always available. BBM Packaging’s technical expertise in the bottling and packaging sector allows it to support customers at every stage, from choosing the most suitable machine to commissioning and after-sales assistance.
- SACMI isobaric bottling machine
- KRONES isobaric bottling machine
- SIMONAZZI isobaric bottling machine
- Other used bottling machines
Conclusion
The isobaric bottling machine represents a fundamental technical choice for those producing carbonated beverages and wishing to ensure quality, efficiency, and long-term reliability.
👉 Would you like to understand whether this technology is suitable for your line? Contact us for a personalized technical consultation.







