Beer is a food product. Therefore the equipment to serve draught beer needs to adhere to the same standards of hygiene as kitchens, plates and cutlery. Hygiene is essential - not only to maintain the beer quality but also to to prevent a food safety hazard.
But within weeks of installing a brand new draught system, deposits begin to build up on the beer contact surfaces. That's because in addition to alcohol and carbon dioxide, finished beer contains proteins, carbohydrates and hundreds of other organic compounds. Yeast and bacteria routinely enter draught systems where they feed on beer and attach to draught lines. Oxygen entering through the faucet and the coupler at each change of KEGs nourishes these flavor-changing microbes and makes them grow faster.
Dirty lines can cause cloudy, over-foaming or flat beers with a off- flavors and can even cause sickness.
Thus, a well-designed and diligently executed maintenance plan ensures trouble-free draught system operation and fresh, flavorful beer.
(Partly taken from draughtquality.org)
The following cleaning parameters have an influence on the success of a cleaning process:
Time: Contact time on the surface being cleaned
Action: Physical force exerted onto the surface
Concentration: Amount of detergent used
Temperature: Amount of energy as heat used in the cleaning solution
Water: Used to prepare cleaning solution
Individual: Worker performing clean-up operation
Nature of Soil: Composition of the soil
Surface: Composition of material is being cleaned
Beverage dispensing systems are of course closed units and physical force is hard to apply (that's why the turbulent flow is important). Also time is always a limiting factor when it comes to line cleaning, and temperature is - depending on the time available - also hard to increase.
By decreasing the power of these factors (Action and Time) you will have to increase the other parameters (Concentration and Temperature) to achieve the same degree of cleaning success. You can however support the factor Concentration by the following:
- construction of system in the best "hygienic design" possible
- quality of inner surfaces (e.g. barrier tubing)
- mechanical aids (turbulent flow)
- luke warm solution (up to 100°F)
- Use a TAP RINSING BALL to flush all faucets daily with warm water!
- When pouring beer, the glass and the beer poured should never touch the faucet!
- The beer cooler is not a fridge for food! Avoid cross contamination and keep your glycol cooler appetizingly clean like a kitchen!
- Treat beer couplers like cutlery - they touch a food product! Couplers have to be thoroughly cleaned at least at every change of kegs!
- In periods of low consumption call your line cleaning company to clean the lines MORE OFTEN and take special care of a daily faucet rinse!
Use a TAP RINSING BALL to flush all faucets daily with warm water!
When beer or soda is not rinsed off the faucets at the end of the day, residues from the beverage, together with oxygen provide "excellent" conditions for microorganisms to grow fast. A study by the Weihenstephan University in Germany, published in Brewing & Beverage Industry International (issue 2/2010) found that dispensing systems with clean faucets had 20 times less contamination than systems with uncleaned faucets. Download the full article!
Tipp: In periods of low consumption take even better care of a daily faucet rinse! Think of it as eating a steak and leaving the dirty plate on the kitchen counter for several days or even weeks... and you get the picture.
We recommend a 4-step-process for cleaning dispensing systems:
1) Pre-rinse lines with tap water to loosen first deposits (that way the chemical can use all its power to work on the hard to clean deposits).
2) Fill the lines completely with alkaline solution (all inner surfaces should be evenly covered with solution throughout the cleaning process); let the solution soak or re-circulate.
3) Check status of hygiene in the lines after the cleaning. If time permits continue to clean until lines are completely free from organics and/or draw conclusions from the test result when planning your future cleaning routines.
4) Flush off the chemical with tap water and check the pH of the last rinsing water matches the pH of the water from the tap. After that, re-connect the kegs and fill the lines with beverage (pour some beverage to make sure lines are completely filled).
COMING SOON: Overview of verification methods.
There are different detergents, which all do different things to deposits:
- Alkaline, caustic detergents (formulated compound)
- Chlorinated alkaline detergents (formulated compound)
- Acidic detergents (formulated compound)
- Chlorinated alkaline additives (additive to caustic)
- Specialty additives (additive to caustic)
- Specialty additives (additive to phosphoric acid)
- Oxidizing sanitizers (NaOCl, mixed halogen) and peracetic acid Acid sanitizers (surfactant and acid).
These chemicals can be effective on several types of soils and not limited to the soils shown below.
Caustic is effective against fats, oils and proteins though process of saponification.
Wetting agents are additive to either alkalines or acids to improve in cleaning through wetting and dispesion.
Chelating or sequesterants are added primarily to treat the water and keep the minerals in supspension.
Chorinated cleaners also add to the cleaning as an oxidizer including fats and proteins but chlorine is not accepted as a cleaner in several applications in the US, particularly on beer contact surfaces. There are other excellent oxidizing agents other then chlorine that are used for cleaning effectively and do not create the concern of off taste such a persulfates.
Acid cleaners are most effective toward removal of inorganic material such as hard water deposits.
It is important to note that in most applications a blend of chemicals is needed to be effective in removal the soils under the conditions present. For example the soils to be removed are a combination of protein, carbohydrates and scale, a caustic solution would work quite effectively on the protein but not so on the other soils present.
Often time in cleaning programs there is the misconception that more is better. This often times happens with caustic levels. As mentioned earlier caustic plays an important role in cleaning of fats and proteins (particularly) but is not effective or less effective in removal of other types of soils. A cleaner should be built to address the variety of soils present and the conditions i.e. time, temperature, actions etc. Failure for the product to meet these conditions will result in less effective or poor results.
A surfactant (surface active compound) is a substance that lowers the surface tension of a solution. A surfactant makes water wetter. Surfactants also foam, control foam, emulsify and disperse soils in solution. Chemically surfactants have anionic, cationic or nonionic (neutral) structures.
Advantages: Through the low surface tension alkaline detergents can better get into cracks or very narrow gaps in the inner surface of the tubing and to their work there.
Disadvantages: Surfactants are bad for the environment and also very hard to rinse out of the line (needs 2-3 times more the amount of water). This is because they make the water "stick" better to the surface. If the lines are not properly rinsed with water after the cleaning process with a chemical that uses surfactants, it has a negative effect on the taste and quality of the beer and the beer gets flat.
That's why we put NO surfactants in TM DESANA MAX and TM DESANA LIQUID, but use a more advanced, more effective way to get access to and work on hidden soils in cracks.
Causticity is the property of a substance that causes corrosion. A corrosive substance is one that will destroy or irreversibly damage another substance with which it comes into contact.
There are 3 different kinds of "caustics", all in the upper range of the pH scale (base):
- Sodium hydroxide (NaOH), sometimes called caustic soda or lye. It's the principal strong base used in most cleaning agents, can dissolve grease, oils, fats and protein based deposits.
- Potassium hydroxide (KOH), sometimes called caustic potash is an inorganic compound and is also a prototypical "strong base" and a component in some cleaning detergents.
- Calcium oxide (CaO), sometimes called caustic (quick)lime. Not used for cleaning purposes.
Caustics should be used just at the right concentration, because if the pH value gets too high, Magnesium is separated from the water in the solution, which leaves a white coating on the surfaces. Also, a too high concentration causes corrosion of the material (in the holes microbes will grow).
Caustics are available to the chemical industry in the form of a 50% solution, 20% solution or solid prills and caustic concentration is correctly declared as "mol per liter".
pH is a measure of the acidity or basicity of a solution. Pure water is said to be neutral, with a pH close to 7.0 at 25 °C (77 °F). Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are said to be basic or alkaline.
Combining material with a low pH and one with a high pH will neutralize it. That's why it's a valuable method of applying first aid help to you "wash" your hands with beer or Cola if you accidently got in contact with alkaline solution - this will neutralize the pH of your skin.
Alkaline cleaning (above pH 7) is most effective to remove the majority of deposits (BIOFILM) and is used to clean beer, wine and soft drink - dispensing installations.
Acid treatment ( below pH 7) is best used for descaling purposes (removing mineral layers in water dispensers, tea cattles, water coolers etc.).
- Lemon juice: pH 2
- Carbonated soda beverage (Cola etc.): pH 2.5
- Vinegar: pH 3
- Beer: pH 4.5
- Human skin: pH 5.5
- Urine: pH 6.0
- Freshly distilled H20 at 37degrees C: pH 7
- Seawater: pH 8
- Household bleach (NaClO solution): pH 12.8
- TM DESANA MAX: pH 12.5