Beer line maintenance: The complete guide to cleaning your draft system

1. Required equipment: The sanitation keg

To clean the inside of a tube, you can’t scrub it with a brush. You must push a chemical agent under pressure through the entire circuit in place of the beer. For this, the key accessory is the sanitation keg:

• In professional environments: Stainless‑steel cleaning kegs are used, equipped with the same couplers as commercial beer kegs (Type A, S, etc.).
• In homebrewing / amateur setups: A simple small Soda Keg or a pressurized PET container such as a 4L or 8L Oxebar works perfectly at a very low cost.

2. The magic products: The color indicator

To know whether a line is truly clean inside, modern cleaning products use revolutionary color‑changing technology. The leading product is TM Desana Max FP (or its liquid equivalent, Pipeline Original).
This powerful alkaline detergent is purple in its pure state. When it comes into contact with organic matter or bacteria, it oxidizes and instantly changes color (it turns yellow if the line is heavily soiled, or green if it is lightly soiled). As soon as the product comes out of your tap still purple, you have visual and mathematical proof that your lines are clean!

3. Diagnostic table: What does your cleaner’s color mean?

During your cleaning cycle, carefully observe the liquid flowing from your tap to adjust your contact time:

4. The step‑by‑step protocol

For optimal maintenance (ideally performed 1 to 4 times per month depending on your serving frequency), equip yourself with protective gloves and follow these steps carefully:

Step 1: Initial pre‑rinse

Before using chemical products, thoroughly clean and pre‑rinse your sanitation keg (SodaKeg or Oxebar), your couplers or Ball‑Lock connectors, and the draft circuit to remove stagnant beer residues.

Step 2: Preparing the reference solution

Pour one 45g sachet of Desana Max FP into your cleaning keg and add 4.5 liters of warm water (ideally 35°C). Close the keg and shake it vigorously three times to ensure full dissolution. Open the keg and take a small sample of the solution in a clear glass: it will be a bright purple. This glass will serve as your “color reference” for the rest of the process.

Step 3: Filling and soaking the lines (20 min)

Connect your CO2 bottle to the sanitation keg to pressurize it, then connect your liquid line (coupler or black Ball‑Lock) to the draft system. Open your tap. As soon as the purple solution begins to flow from the faucet, immediately close the tap. The product is now trapped inside the line: let it act for 20 minutes.

Step 4: Soaking external connectors

While the product dissolves the biofilm inside the tubing, disconnect the CO2 and depressurize your cleaning keg. Open it and submerge your Ball‑Lock connectors or coupler directly inside the keg to disinfect external threads and seals during the remaining 20 minutes.

Step 5: Flushing and color verification

Close the keg, reconnect the CO2, and open the tap again to flush out the product. Observe the color of the liquid:

• If the product comes out green or yellow, close the tap and let it act for 3 more minutes. Repeat until the liquid comes out fully purple, identical to your reference glass.
• Once purple is stable, let the remaining product flow until the sanitation keg is empty.

Step 6: Final safety rinse

This step is crucial to avoid detergent traces in your next beer. Disconnect the keg, rinse it thoroughly with clean water, then fill it with tap water. Reconnect it to the system and run all the water through the lines.
Pro tip: Use a small pH test strip. The pH of the water coming out of your tap at the end of rinsing must be strictly identical to the pH of your original tap water.