How to pressurize a beverage can with CO2 while avoiding carbonation

The Role of Gas Solubility

How to pressurize beverage can, the choice of gas is critical. Carbon dioxide (CO2) is highly soluble in water, meaning it easily dissolves into the liquid2. As CO2 dissolves, it forms carbonic acid, which gives carbonated drinks their fizzy, bubbly taste2.In contrast, nitrogen gas (N2) is much less soluble in water1. This makes nitrogen ideal for pressurizing a can without causing carbonation. However, nitrogen requires higher pressure to dissolve compared to CO21.

Pressurizing with Nitrogen

To pressurize a can with nitrogen, you'll need a few key pieces of equipment:

1. A nitrogen gas tank
2. A pressure regulator to control the gas flow
3. Tubing to connect the regulator to the can

First, seal the empty can. Then, use the regulator to slowly inject nitrogen gas into the sealed can through the tubing1. The nitrogen will fill the headspace above the liquid, creating pressure inside the can.To avoid having the nitrogen dissolve into the liquid and cause carbonation, it's important to:

1. Keep the can at room temperature. Colder temperatures increase gas solubility2.
2. Minimize agitation and movement of the can. Shaking or stirring the liquid can cause the nitrogen to absorb2.
3. Use a higher pressure of nitrogen. More pressure helps keep the gas in the headspace1.

As long as the nitrogen stays in the headspace and doesn't dissolve into the liquid, the can will remain pressurized without becoming carbonated.

Pressurizing with CO2 While Avoiding Carbonation

While nitrogen is the preferred gas for pressurizing without carbonation, it is possible to use CO2 as well. Here's how:

1. Partially carbonate the beverage using CO2 to the desired level, typically around 2 volumes of CO23. This can be done by force carbonating the liquid in a sealed container at a specific pressure and temperature.
2. Rack or transfer the partially carbonated liquid into the sealed can or container that needs to be pressurized3. Make sure to minimize agitation and exposure to oxygen during this process.
3. Disconnect the CO2 supply and relieve any pressure in the headspace of the can3.
4. Connect a CO2 regulator and tank to the can. Back the adjusting screw on the regulator all the way out3.
5. Open the valve on the CO2 cylinder to begin gas flow. Using the adjusting screw, set the pressure to around 25 psi3. Pour a sample and adjust the pressure as needed.

The key is to only use enough CO2 to provide the desired level of carbonation, then use the CO2 pressure to push the liquid out of the can without adding more dissolved CO23. The partially carbonated liquid will not become over-carbonated.

Benefits of Pressurization

Pressurizing a beverage can offers several advantages:

1. The can maintains its shape and won't get crushed, even when empty1.
2. The drink stays at the desired carbonation level, neither over-carbonated nor flat3.
3. Pressurization helps maintain the drink's quality and shelf life by preventing oxidation and spoilage1.

By carefully controlling the pressurization process and choosing the right gas, you can keep your beverage cans pressurized without unwanted carbonation or changes to the liquid.

Nitrogen vs. CO2 for Pressurization

While nitrogen is the preferred gas for pressurizing without carbonation, there are some key differences between using nitrogen and CO2:

• Nitrogen creates a smoother, creamier texture in the drink due to its smaller bubble size compared to CO22. However, it requires higher pressure to achieve the same effect.
• CO2 is more readily available and easier to work with than nitrogen in many cases. It's also cheaper and more commonly used in the beverage industry.
• Nitrogen is an inert gas, so it won't react with or alter the flavor of the beverage1. CO2 can potentially affect the taste, especially if over-carbonated.
• Nitrogen is less soluble in water, so it's less likely to cause carbonation if the pressurization process is not carefully controlled12.

Ultimately, the choice between nitrogen and CO2 for pressurization depends on the specific requirements of the beverage, the equipment available, and the desired effects on texture and flavor.

Pressurization Methods

There are a few different methods for pressurizing beverage cans with nitrogen or CO2 while avoiding carbonation:

1. The "Beer Gas" Method3:
   • Partially carbonate the beer with CO2 to around 2 volumes
   • Rack the beer into a keg and chill to facilitate gas absorption
   • Disconnect the CO2 and relieve pressure in the headspace
   • Connect a nitrogen/CO2 mix regulator and tank to the keg
   • Set the pressure to around 25 psi and pour a sample to adjust
2. The "Nitrogenation" Method4:
   • Attach a stainless steel diffusion stone to the gas-in dip tube of the keg
   • Cold-condition the beer to maximize yeast flocculation
   • Keg the beer and chill to 35°F
   • Connect the nitrogen regulator/tank and set pressure to 15 psi for 1 hour
   • Close the tank valve and relieve pressure in the headspace
   • Connect the liquid line and open the tank valve
   • Set the dispensing pressure to 35 psi and pour a sample to adjust
3. The "Partial Carbonation" Method3:
   • Partially carbonate the beverage with CO2 to the desired level
   • Rack or transfer the liquid into the sealed container
   • Disconnect the CO2 and relieve pressure in the headspace
   • Connect a CO2 regulator/tank and set pressure to around 25 psi
   • The partially carbonated liquid will not become over-carbonated

The specific method used will depend on the equipment available, the type of beverage being pressurized, and the desired effects on texture and flavor.

Conclusion

Pressurizing beverage cans with nitrogen or CO2 while avoiding carbonation requires careful control of gas solubility, pressure, and temperature. By partially carbonating the liquid, minimizing agitation, and using the right gas at the appropriate pressure, it's possible to maintain the desired carbonation level while providing the benefits of pressurization.

Whether using nitrogen for its smooth, creamy texture or CO2 for its availability and ease of use, the key is to keep the gas in the headspace and out of the liquid itself. With the right techniques and equipment, you can create perfectly pressurized beverage cans without unwanted carbonation.

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