Current Progressive Dairy digital edition

0909 PD: Improve your CIP performance, efficiency

Ron Robinson Published on 05 June 2009

Are you looking to maximize milk production and attain higher milk quality premiums?

The solution to achieving these goals may be as simple as improving your milking system’s CIP (clean-in-place) performance and efficiency. Milking equipment cleanliness and proper functionality play a big role in improving or maintaining a low standard plate count (SPC) or bacteria count.

With quality milk premiums and production at stake, let’s take a look at CIP basics.



Milk “soils” which challenge milking system cleaning, include proteins, microorganisms, minerals, sugars and fatty acids. It is believed that today’s high-producing cows create six different types of fatty acids, causing additional cleaning challenges. If done properly, the CIP process attacks each of these challenge areas. The process generally consists of four phases: pre-rinse, cleaning (single- or two-step), acid and sanitizing.

Pre-rinse phase
An effective cleaning process starts with an adequate pre-rinse phase. This phase should remove 90 percent to 95 percent of milk’s soils. To effectively remove contaminants, we recommend flushing the system with 110°F to 120°F water. Do not re-circulate this rinse water; divert it to a drain. Keep flushing until the rinse water is clear. This is an absolute must!

We recommend flushing to remove nearly all soils in the pre-rinse phase. The majority of cleaning challenges we find on farms are traced back to inadequate pre-rinse procedures. These operations attempt to make up for inadequate pre-rinse procedures by using a higher concentration of chemicals. This costs the producer more than just money; there’s potential for increased groundwater contamination and possible system damage, including discoloration of stainless steel and damage to plastic and rubber components.

Cleaning phase
The cleaning phase, which follows the pre-rinse phase, can be either a single-step or two-step process, depending on the detergents selected. Cleaners carry out four basic functions to keep soils in suspension until evacuation: 1) penetrate soil, 2) lift soil from surface, 3) break up soil into small particles and 4) saponify (decompose) fatty acids.

Most detergents consist of two main ingredients, chlorine and sodium hydroxide or potassium hydroxide. Chlorine removes protein, while sodium hydroxide or potassium hydroxide removes fat. To be effective, detergents need the correct wash water temperature throughout the wash cycle. Water at the end of the cycle must be a minimum of 120°F; on most farms that means starting temperatures need to be approximately 160°F.


If these temperatures cannot be achieved, producers need to use products specifically designed for lower water temperatures. Also, producers must use the correct amount of detergent, based on factors relevant to the dairy, such as water hardness, iron content, water use, soil type, soil load and size and type of equipment.

Acid phase
Because detergents (soaps) and chlorine always leave behind mineral deposits, the acid phase follows the cleaning phase. Acids are most effective at removing detergents and chlorine. Add just enough acid to warm water (100°F to 120°F) to get a pH of 3 to 4. If the acid rinse is 68°F or lower, use a non-foaming acid. If silicates are present in the dairy’s water, do not let the pH drop below 5.

Sanitizing phase
The final step is the sanitizing phase. To comply with Pasteurized Milk Ordinance (PMO) regulations, circulate a Food and Drug Administration-registered sanitizing solution, according to the manufacturer’s guidelines, no more than 30 minutes prior to the next milking shift. If producers follow the recommended sanitizing phase, 99.9 percent of bacteria should be eliminated.

Prevent buildups
Over time, protein, fat and mineral buildups occur in pipelines. Proper cleaning procedures should reduce or eliminate buildup. Strive to clean the system with a consistent, cost-effective and environmentally friendly procedure.

Most dairy producers are interested in implementing cleaning practices that foster sustainability and environmental stewardship. Consequently, chemical products and recommended cleaning procedures should work to save valuable resources – water, energy, environment, time and money. For example, using a single-step cleaner reduces wash cycles by combining the detergent and acid phase, which helps conserve water, energy and time, while effectively preventing buildup.

While reducing cleaning time is an admirable goal, you must always allow enough time so the cleaning chemicals penetrate the soil, lift the soil from the surface being cleaned, break the soil into tiny particles and saponify the fatty acids. This usually requires a minimum of 20 to 25 proper slugs in the system.


Surface type impacts ease of cleaning
Whether it’s a milking parlor or manufacturing plant, the most difficult surfaces to clean are rubber and plastic, as opposed to stainless steel. Rubber and plastic experience quick temperature changes on the surface, plus they are porous, allowing oils and fats to penetrate and adhere. Stainless steel maintains a consistent temperature and is nonporous. The correct surface temperature is critical to foster effective water contact for proper cleaning.

In general, the smoother/harder the surface, the easier it is to clean (See Table 1*). However, several other factors also impact which concentration and cleaning product formulation to use, including water temperature, water hardness and iron content, soil type, size of system to clean and length of milking time.

Surface cleaning comparisons, based on time/ease of cleaning
While higher chemical concentration can improve cleaning performance, too high of a concentration may cause cleaning problems, accelerate equipment wear and lead to the overuse of acid to remove chemical residues. With too low of a concentration, equipment will not clean properly, potentially resulting in elevated bacteria counts and ultimately loss of milk quality premiums.

Another factor: Properly functioning equipment
If equipment is not functioning properly, a cleaner’s effectiveness will be challenged. Follow the manufacturer’s recommendations regarding air injectors so each slug completely transverses the entire milking parlor pipeline without breaking down. Also, the slug must maintain adequate shear force during its circuit so the cleaning action is consistent throughout the entire system. This process physically removes soils from the surface, disperses soil in the solution, prevents soil from re-depositing on the surface and increases chemical action by renewing the chemical solution on the soil surface.

Similarly, follow the manufacturer’s recommendations for maintaining jetter cups, duck bills and milk pump seals. The same applies to vacuum regulators and pulsators. Proper vacuum is 11 inches of mercury (in Hg) to 13.5 inches of mercury (in Hg), depending on the system and where in the system vacuum is checked. Furthermore, monitor CIP solutions – ensuring that systems are functioning properly and chemical levels are in check.

Follow guidelines and lower costs
By following these basic CIP guidelines, dairies should lower sanitation costs, reduce energy costs and decrease wear on milking system equipment. And, best of all, dairies should meet the milk quality goals in Table 2*.

In summary, remember that several factors impact cleaning – time, temperature, chemicals/concentration, mechanical effect, water quality, soil being removed, type of surface being cleaned, cleaning method and people. To maximize cleaning effectiveness, make sure each factor is performing at its optimum.

Just like a sports team, it takes teamwork to maintain an efficient and properly functioning milking system that fosters quality milk production. I recommend creating and working with a milk quality team, which should include your milk cooperative field representative, veterinarian, financial adviser, equipment service technician and chemical company representative. This group can set standard operating procedures for the dairy’s employees and monitor the results. The team should meet (at least) once a quarter to review results and progress, and develop and implement any necessary new action steps to improve quality milk production.PD

Ron Robinson

*Tables omitted but are available upon request

Want to know how well your CIP system is doing? Submit a photo of your CIP challenges or a question to Progressive Dairyman. In future issues, A&L Laboratories experts will comment on the photos or questions. Dairy names and locations will not be connected with photos, so your review will be completely anonymous. Send your photos and questions to

Ron Robinson
Vice President
Business Development
A&L Laboratories