How To Properly Wash Kegs

Why Next-Day Drinks Delivery Is Cheaper with a 3PL (and Unsustainable In-House)

Take it from us- managing a fleet of kegs is about more than just re-filling and delivering. You have to consider:

• Cleaning of kegs
• Sanitising of kegs
• Quality checks to ensure the kegs are in a “ready to refill” state.
• Returning of kegs back to the brewer

If you’re outsourcing your keg washing (or even just thinking about it), here’s how the process works- and why our NEW Tap’in South-East Wash Hub is a game-changer, especially for brewers based in the South East. The Keg Cleaning Circle: From Return to Refill.

Here’s a step-by-step breakdown of how keg washing generally works in an outsourced washing situation (NOTE: cleaning cycle may vary depending on the machine used to wash the kegs):

Collection of Empty Kegs

• Once your customers (venues such as pubs, bars and restaurants) have emptied their kegs, they are collected by the 3PL’s logistics team. At Tap’in 3PL, our drivers collect empty kegs from the venues they’re delivering fresh drinks in a more eco-friendly way than standalone keg collections!

• The outsourced keg wash 3PL will bring the collected dirty kegs back to their keg wash HQ, sorting them by size (e.g., 20L, 30L, 50L) and double-checking each one for damage or defects.

• Any faulty kegs are flagged to notify the keg owner of required maintenance or repair.

Pre-Rinse/Residual Purge

• The first cleaning stage is a purge to remove residual beer and CO₂. This step helps expel leftover product before any cleaning chemicals are introduced.

• After purging, a cold water rinse is used to flush out larger particulates.

Caustic (Alkaline) Wash

• A hot caustic cleaning solution will circulate through the keg. This breaks down organic residues found in beer (yeast, beer stone, protein deposits).

• For the above, automated keg washers are used- they’re capable of handling multiple kegs per hour. At Tap’in, we have a state-of-the-art Lambrechts keg wash machine.

Intermediate Rinse

• After the caustic wash, kegs are rinsed with clean water to remove chemical residues.

• Rinsing the kegs is critical to protect your beer’s flavour and ensure no cleaning solution remains that could contaminate the next batch.

Acid/Sterilisation Cycle

• Depending on the keg wash machine’s configuration, there may be an acid sanitisation cycle.

• Steam sterilisation hold (steam purge) is added to ensure keg sterility.

Pressure Purge & Final Pressurisation

• After sanitisation, we purge out any leftover sanitiser (usually via CO₂ or sterile gas) to avoid oxygen ingress or chemical residue.

• The keg is then pressurised (often using CO₂) to a safe storage pressure so it’s stable and ready to refill.

Quality Check & Inspection

• Each cleaned keg is visually inspected and checked for any signs of corrosion or damage.

• A verification check (e.g., ATP-swab, microbial test) may take place to ensure cleanliness standards. (Rotech/anton-par/acid/alkalinity carbonate test kit)

• Defective kegs are quarantined for re-cleaning or refurbishment.

Storage & Return to Brewer

• Once kegs are cleaned and deemed “ready to refill,” they are stored under pressure in our ready-to-refill inventory.

• Depending on the keg wash service provider, drinks producers can either collect their kegs once they’ve been washed or sterilised, or the outsourced keg wash service can schedule the return of the kegs to wherever they need to go, just in time for their next fill run.

Refill Cycle

• The brewer receives their ready-to-refill kegs and fills them with fresh beer.

• After filling, the cycle repeats, empty kegs are collected, washed & sanitised and then stored to collect by brewer/return is organised by the keg wash service provider.

At Tap’in Wash Hub, our keg wash machine uses 5 different ‘wash heads’, giving the keg a throughough wash and steam to ensure it cleaned and sanitised, ready-for-refill.

Pros & Cons: In-House Washing vs Outsourcing Keg Washing

Here’s a comparison of washing kegs in-house vs outsourcing to a specialised 3PL wash hub like Tap’in South-East Wash Hub: