by Jamie Martin, Brewmaster, Dells Brewing Co.
The cleaning process and chemicals a brewer chooses vary widely from brewer to brewer and worksite to worksite; many factors contribute to the costs involved in this very important and essential aspect of brewery operation.
Chemical and equipment requirements are determined by the personal preference/training of the brewer as well as; mandated health/workplace code requirements, type of surface, contaminate (soil), and brewery environment.
Like brewing, there is more than one right-way to clean. But there are three controllable variables that will determine how effective your cleaning process is no matter what process or chemical you chose to use. Time, Temperature, and Concentration are the variable factors in all cleaning processes, and being able to control and optimize each variable for your particular process will determine how effective your clean-up efforts are.
Temperature:
Pasteurization temperature is 140oF. Cleaning is most effective above 140oF but below 180oF. Just like in the brewing process temperatures over 180oF will cause some organic contaminates to precipitate proteins which can inhibit cleaning. Controlling temperature is not as simple as heating your water to 140oF and spraying down the area you want to clean. Remember, heat is exchanged and lost during the transfer of water for the cleaning process so the temperature you start with is not necessarily the temperature you end up running with. In order to make sure you are within the optimal temperature range for your cleaner and process:
1. Check with your chemical supplier. They know their product better than anyone.
2. Run a test cycle and check the temperature of your cleaning solution at the beginning, in the middle and at the end of your cleaning process to determine how much heat is lost.
This information allows you to make adjustments to your starting temperature so you can maintain an optimal temperature range for the entire cleaning process.
Time:
Establish a minimum time for all cleaning procedures! Time is a wonderful variable because unlike temperature and concentration you can increase it without serious consequences. For example, if you are cleaning at the lower end of the optimal temperature range for your cleaning agent, increasing the cleaning time increases the effectiveness of your sanitation process.
When it comes to cleaning time, tanks and vessels in the brewery are not all created equal. Fermenters require more time and action than bright tanks; certain yeast strains make bigger messes and need a longer cleaning cycle, and dirty kegs that have been left out always need extra attention.
Concentration:
This variable can either save or cost you a lot of money. More is not better. A high concentration of cleaner, especially caustic cleaner, can create pitting in stainless steel surfaces which will drastically shorten the usable life of that piece of equipment.
Know your concentrations; measure, don’t just guess or assume! Check concentration by using test strips and or pH (ask your supplier what the optimal range for your particular chemical and process). Many cleaners can be reused as long as it is still in the optimal range of pH and concentration. If it is not, often it can be made viable with a slight adjustment.
Acid Cycle:
After the cleaner cycle you’ll ask yourself “Why should I run an acid cleaning cycle when the vessel looks perfectly clean?”
Cleaners are great for removing tough organic soil from the surface of stainless steel, but the additional acid cycle is required to remove inorganic material that could be hiding in the pores of your stainless steel that standard cleaners are too large to penetrate. Also, most cleaners are very sticky and, even after a good hot water rinse, there can still be residue. The acid cycle will remove the inorganic solids, beer stone, hard water, minerals and residue left over from the initial cleaning cycle.
The addition of an acid cycle also, when using an approved inorganic blend, adds a protective Passivation* layer to your stainless steels surface. This additional step can add extra life to your stainless. How often? Every time ideally, but if cost is a issue every third cleaning cycle.
*(Passivation – the removal of free iron particles or iron compounds from the stainless steel surface by means of a chemical dissolution, most typically by a treatment with an acid solution.)
Sanitation:
You can’t sanitize dirt! Sanitizer is not the fix-all miracle solution many believe it to be. Sanitizer is only effective on completely clean surfaces. A cleaner can not sanitize and a sanitizer can not clean. These are different processes with distinct and separate goals.
Also:
Most sanitizers are oxidizers, making it very important to insure your vessel is dry before you fill it; otherwise residual sanitizer could potentially oxidize your beer. Unlike certain cleaners, You can not reuse sanitizer!
Special Cleaning Concerns
Heat exchangers:
With lots of small, tight channels, there are many places for critters to hide in your heat exchanger. Give it the extra attention it deserves. Back flushing your heat exchanger after every brew at 1.5 times the speed of your transfer is very effective in breaking up and off soil that pressure and high temperatures fuses to the plates.
As part of your regular quarterly planned maintenance I recommend opening up the heat exchanger for visual inspection. It is the only way to know for sure if your cleaning regiment is effective.
PRVs, sample valves, sight glass valves & faucets
These valves have tiny parts and crevices that normal cleaning/CIP processes can and will miss. They need to be removed, taken apart, cleaned by hand and visually inspected after each brewing cycle.
Gaskets
Gaskets do not last forever. Inspect them closely each time you clean and insure they are crack-free. As soon as a crack forms, the gasket becomes a possible source of contamination, you need to replace the gasket because the cracks make it impossible to ever truly get it clean or sanitized.
Pipe and hose lines
Keep them the same size all the way through the process. If you HAVE to change sizes, ALWAYS go from big to small! If you go from small to big the bigger pipe/hose will never get fully cleaned or sanitized.
Oxygen Lines and CO2 Lines – Many people forget to clean and sanitize these because beer doesn’t actually come into contact with them. The truth is that these are very common places for contamination in the Brewhouse because they are neglected and ignored. Gas is passed through these lines and into your beer! They should be cleaned and sanitized before every use.
CO2 will neutralize your Caustic & render it useless – Vent & purge CO2 before your caustic cycle. Especially when cleaning kegs use compressed air, not CO2, to push caustic cleaning chemicals out of the kegs. Or use a caustic alternative.
Inspect! Inspect! Inspect! Visual inspection is the only way to truly know your equipment is clean – open it up and check it out! – Kegs, take the stem out; tanks open them up and inspect with a flashlight; Heat exchangers and valves, open them up for visual inspection.