Best Practices for Slow and Low Purging of an Empty Bright Tank

Properly purging a bright tank is essential for reducing dissolved oxygen (DO) and maintaining beer quality. A slow and controlled CO₂ purge ensures effective oxygen removal without unnecessary turbulence or gas waste. Implementing best practices will help brewers achieve optimal results while conserving resources.

Start Slowly

Introducing CO₂ at a low flow rate (0.5-1 bar or 7-14 psi) allows for a controlled purge without generating excess pressure or turbulence. A gradual flow helps CO₂ displace oxygen effectively, ensuring a complete purge without excessive gas usage.

Vent Arm Setup

• Connect the BrewOps Purge and BrewOps Modified Tee directly to the CIP arm, ensuring no valve is placed between the arm and the tee.
• The modified tee creates proper back pressure, optimizing the purging process and sensor accuracy.
• By eliminating a valve, the risk of accidental closure is removed, preventing dangerous pressure buildup.

If the BrewOps Modified Tee is unavailable:

• Use a standard or instrument tee.
• Attach the BrewOps sensor to the side port of the tee and a butterfly valve to the bottom port.
• Keep the top of the tee valve-free to avoid accidental closure.
• Open the butterfly valve about ¼ of the way to maintain proper back pressure (4-5 psi).
• You should hear and feel gas escaping through the holes in the BrewOps Purge housing.

Monitor Purge Level

Using the BrewOps Purge to monitor your process ensures you reach the desired oxygen concentration. You will observe:

1. A gradual decrease in oxygen levels.
2. A sharp drop as oxygen is fully displaced.
3. A plateau at a low, stable oxygen level.

Be mindful of diminishing returns—continuing the purge beyond this point may not significantly reduce oxygen further and could lead to wasted CO₂.

Final Checks

• Remove the gas line, BrewOps Purge, and the modified tee.
• Ensure all valves are closed and clamps are tightened to prevent leaks.
• Maintain a slight positive pressure (~5 psi) in the tank to keep oxygen out.

By following these best practices for slow and low purging, brewers can effectively remove oxygen, preserve beer quality, and optimize CO₂ usage.