Draft beer lines are the tubes that carry the finished beer from the keg or tank to the faucet. Cleaning these lines is important for maintaining the intended flavor profile, ensuring consumer safety, and preserving the operational efficiency of the entire draft system. Unclean lines can severely impact the quality of the product, leading to off-flavors and excessive foaming that costs businesses revenue.
Establishing the Standard Cleaning Frequency
The industry-wide recommendation for maintaining optimal draft beer quality is to clean the beer lines every two weeks. This standard is established by major organizations, such as the Brewers Association, which publishes comprehensive guidelines for draft beer quality management. Following this 14-day schedule is considered the minimum requirement to prevent the growth of microorganisms and the buildup of deposits that compromise the beer’s integrity. Adherence to this frequency ensures consistency in taste and appearance, protecting the investment in high-quality draft beer.
Understanding the Contaminants and Risks
Neglecting the established cleaning schedule allows for the accumulation of biological and mineral contaminants within the tubing. Wild yeast and bacteria are the most common biological culprits, quickly forming a biofilm on the line’s interior surface. These microbes consume residual sugars in the beer and produce undesirable byproducts, such as diacetyl, which imparts a sour or buttery off-flavor to the dispensed product. Mold frequently develops in areas exposed to air, particularly around the faucets and couplers, posing a sanitation risk. A mineral deposit known as beer stone also forms inside the lines, creating a rough surface that shields the bacteria and yeast from cleaning solutions, making sanitation increasingly difficult over time.
Factors That Demand Increased Cleaning Frequency
Beer Type and Sugar Content
The composition of the beer being served influences how quickly residue accumulates, often necessitating a cleaning schedule more frequent than the bi-weekly standard. Beers with high sugar or protein content, such as stouts, wheats, and fruit-infused sours, leave behind more organic material inside the lines. This residual material provides a richer food source for the yeast and bacteria, accelerating the formation of biofilm and requiring an often weekly cleaning interval.
System Age and Configuration
Older draft systems or those with complex layouts, such as long runs or systems with poor insulation, are more susceptible to contamination. Longer lines mean the beer spends more time in transit, increasing the opportunity for microbial growth and temperature fluctuation. Older tubing materials can develop microscopic cracks or surface roughness, making it easier for contaminants to adhere and form persistent biofilms.
Temperature and Environment
Elevated ambient temperatures in the storage or serving area accelerate the reproduction rate of beer-spoiling microorganisms. If the temperature of the walk-in cooler or the draft line bundle is not consistently maintained within the ideal range, the bi-weekly cleaning interval may prove insufficient. High cellar temperatures create a more hospitable environment for biological growth, demanding a weekly cleaning to stay ahead of the microbial proliferation.
Low-Volume Lines
Lines that dispense low volumes of beer and sit stagnant for extended periods are prone to rapid spoilage. When beer remains static in the tubing for several days, the dissolved oxygen is consumed, and microorganisms have an undisturbed opportunity to multiply. This lack of flow means the line should be cleaned weekly, or immediately after a keg is changed, to prevent the growth of off-flavor-producing bacteria.
The Essential Steps of Professional Line Cleaning
Professional line cleaning follows a multi-step chemical process to ensure every contaminant is removed, beginning with disconnecting the kegs and attaching a cleaning solution container to the system’s coupler. The cleaning solution is then circulated through the entire line, often using a recirculating pump, which helps to scrub the line’s interior surface. This circulation is maintained for a specific contact time to allow the chemical to penetrate and break down the biofilm. Following the chemical wash, the lines must be thoroughly flushed with fresh, potable water until the water’s pH is neutral, confirmed using pH testing strips. The final step involves manually disassembling the faucets and couplers to scrub away any physical buildup, as these parts cannot be fully cleaned by the circulating solution alone.
Choosing and Handling Cleaning Solutions
Effective line cleaning relies on the correct application and rotation of two types of chemical cleaners, each targeting a different kind of residue. Caustic, or alkaline, cleaners are designed to remove organic matter, such as yeast, bacteria, and protein buildup, and should be used every two weeks as part of the standard cleaning cycle. Acid cleaners are formulated to dissolve beer stone, the inorganic mineral deposits. These acid washes must be performed on a regular rotation, typically every three months, to maintain a smooth line interior. Due to the corrosive nature of both alkaline and acid chemicals, personnel must always wear personal protective equipment, including gloves and eye protection, and ensure the chemicals are never mixed, as this can create dangerous gases.
Maintaining Records and Quality Control
The final step in a professional line cleaning regimen involves documentation and quality control. A cleaning log must be maintained, detailing the date of the service, the chemical used, the duration of the contact time, and the employee or technician responsible for the cleaning. This record provides an auditable history and helps identify any patterns of quality issues. Post-cleaning quality control checks include tasting the first few pints dispensed to confirm the absence of chemical residue or off-flavors. Staff should regularly monitor the temperature of the draft system to ensure it remains within the optimal range.