Breweries clean kegs using a combination of hot water and alkaline cleaning solutions. The process involves the use of either sodium hydroxide (NaOH) or potassium hydroxide (KOH), which are highly alkaline substances with a pH ranging from 12 to 14. These solutions are effective in breaking down and removing soil from the kegs.
The first step in the cleaning process is to empty the kegs of any remaining beer or other liquid. This is usually done by tapping the keg and allowing the contents to flow out. Once the keg is empty, it is ready for cleaning.
Hot water is then used to rinse the keg and remove any remaining residue. The temperature of the water is generally around 140-160°F (60-70°C), as this helps to loosen and dissolve any stubborn soils.
Next, an alkaline cleaning solution is prepared by dissolving sodium hydroxide or potassium hydroxide in hot water. The concentration of the solution may vary depending on the specific requirements of the brewery and the degree of soiling on the kegs.
The alkaline solution is then circulated through the keg, either manually or using automated cleaning systems. The high pH of the solution helps to hydrolyze the soil, breaking it down and making it easier to remove. The cleaning solution is typically left in contact with the keg for a certain period of time to allow for effective cleaning.
During this contact time, the alkaline solution reacts with the soil, breaking down organic matter and removing any mineral deposits. The combination of high temperature and alkalinity helps to dissolve and emulsify fats, proteins, and other residues that may be present.
After the contact time, the keg is thoroughly rinsed with hot water to remove any remaining cleaning solution. This step is crucial to ensure that no traces of the alkaline solution are left behind, as it can affect the taste and quality of the beer.
In some cases, breweries may also use mechanical scrubbing or brushing to remove stubborn soils or deposits. This can be done manually or with the help of automated cleaning equipment. The use of brushes or scrubbing pads can help to agitate and dislodge any remaining residues.
Once the keg has been cleaned and rinsed, it is typically inspected for any signs of damage or wear. This includes checking for leaks, dents, or other issues that may affect the keg’s performance. If any problems are found, the keg may be repaired or replaced as necessary.
The cleaning of kegs in breweries is a critical step in maintaining the quality and integrity of the beer. The use of hot water and alkaline cleaning solutions helps to ensure that kegs are thoroughly cleaned and ready for the next batch of beer to be filled.