The (cleaning in place) CIP equipment sanitation process is vital to any brewery because not properly cleaning equipment can lead to uncontrollable flavors in the beer. The CIP can be portable or stationary, and can contain single, multi, and re-use tanks. The CIP process follows a general guideline when cleaning any piece of equipment which is pre-rinse, alkaline detergent wash, rinse, Acid wash, rinse, and sanitize. Some important variable when doing the CIP process is the concentration of cleaning solution, time of each step, and temperature at each step is critical. The items necessary for the CIP is a storage vessel for all the cleaning solutions, usually referred to as the CIP cart. Next item needed is a pump that is properly sized for your system to handle a certain volume of liquid. The last item needed for non-mechanical cleaning of vessels is the CIP spray ball that is usually mounted at the top of a cellar vessel. The importance of the CIP spray ball in larger systems is that if manually cleaned the scouring of the inside of the tanks make it easier for bacteria growth on the affected area. But the spray ball ensures that every surface inside the tank will get hit because of the 360 degree coverage of the sphere.
The First part in the clean in place process is the pre-rinse to remove any visible organic material without the introduction of chemicals. This takes approximately 15 – 30 minutes. The pre-rinse temperature of the water should be cold or room temperature water to ensure that organic material will not be baked onto the side of the vessel.
Second phase of the process is to fill the vessel with the alkaline based detergent that breaks down organic materials by hydrolyzing peptide bonds, and breaking down insoluble protein bonds into soluble material. Most popular alkaline based detergent is caustic soda or otherwise known as sodium hydroxide. It has strong penetrating abilities for proper saponification of fatty and protein like soils. The caustic is best used in a temperature range from 140 – 180 Fahrenheit or 60 – 82 Celsius. The vessel being cleaned will be filled with the caustic soda and looped through the system so that every surface the wort touched is being cleaned, from the plate heat exchanger to every piece of tuning in the brew house.
After the caustic loop has been completed it is time to do a hot rinse of the caustic on all ports the caustic has touched. Be sure to remove any valves, c clamps, and gauges for a soak in the caustic solution. A thorough rinse is required after the caustic loop, and some brewers save on the cost of alkaline based detergent by recovering used caustic and reusing it to clean other vessels.
The third phase of the cleaning process is the acid cycle, where a phosphoric acid, nitric, acid, or a combination of both will be added to the vessel. This is an important step because it does three main things, first is that the acid neutralizes the caustic that may be left over from the previous cycle. Second the acid breaks down in-organic materials leftover from brewing like beer stone, hard water deposits, and mineral deposits. Lastly the acid wash repairs the stainless steel’s integrity, by passivating or removing the upper layer of iron that has deposited on the stainless steel by re-oxidizing the upper layer of chromium.
The final phase after the organic and inorganic material from the vessels have been removed the last part is to sanitize the vessels from any microbes. The sanitization of tanks can be achieved by chemical disinfectants that kill microorganisms. Some sanitizers are a no rinse needed solution like Iodophor that does not need to be rinsed out of the vessel. A drawback to using sanitizer is that the vessel must be completely dry before filling with sanitizer because sanitizer is an oxidizer you do not want residual sanitizer oxidizing the beer during fermentation.
To bring the CIP process into perspective each step in the process has a role on the big picture of equipment cleanliness. From the breaking down of organics by the caustic, then the acid breaks down inorganics, and the sanitizer disinfects from any microorganisms. The CIP removes human error from the equation by use of the spray ball; it also can utilize the reuse of chemicals to save cost, and limits the exposure of harmful chemicals to the person operating CIP. Some areas of concern when routinely cleaning your equipment is understand vacuum relief so that a vacuum isn’t created inside a vessel when cleaning. Next are some special areas to consider during CIP one is the plate heat exchanger, with very small cracks and crevices it is an area that needs to be scrutinized during CIP. Another area of concern is any peripheral elements of the vessel, for example sight glasses, sample valves, faucets, and carb stones. Third area of concern while cleaning is the gaskets between metal to metal contact points are build up areas. Lastly are the gas, CO2, and oxygen lines that are externally equipped can bring about concerns of unsterile environment.