Cleaner at the Brewery Part 1
With the existing Safer at Home order in place in Wisconsin and similar stay at home orders throughout the Midwest, why not take this time to get some deep cleaning done at the brewery? This is a great opportunity to dig in and clean some of those items on your list that have been put on the back burner for too long. Here is the first of a four-part series – “Cleaner at the Brewery” where I share ideas on how making time for deep cleaning now will help improve quality and efficiencies when production scales back up. So, pry yourselves away from your computer, tablet, or phone and get out on the brewery floor. Less screen time and more clean time. Don’t forget your PPE!
Today’s topic is heat exchangers. One of the most common type of heat exchangers we see on wort cooling lines is the plate heat exchanger- often called the wort chiller. For most beer styles, the final product quality depends on how quickly the wort is cooled, so wort chillers are designed to cool wort as quickly as possible. This means high surface area at a controlled flow rate- usually as fast as possible while hitting the target temperature for pitching yeast in the fermenter. It’s that same property of high surface area which also poses some challenges with turbulence or mechanical action when cleaning. I’ll get to that in a minute.
The chemicals selected for cleaning the brewhouse are also used for cleaning the wort chiller. Traditionally, this would be a blended caustic wash with Pursuit RSTM at about 1.5-2.5% causticity followed by a nitric/phosphoric acid blend wash with Pass ECNTM at around 0.1-0.2% acidity. The acid wash reduces inorganic mineral build-up of calcium oxalates or beer stone, and will remove any mineral deposits left from the caustic wash. Following the CIP wash, the wort line and chiller should be sanitized with a peracetic acid such as Perasan ATM.
Now, let’s talk about flow rates. During CIP, you want the flow to be twice the flow rate of wort when you are running wort to the fermenter. Sometimes equipment might limit your ability to hit these higher flow rates. If you can’t hit the double flow rate mark, then then shoot for a minimum of 30% over your production flow rate. The increased flow is important to get the turbulence across the plates needed for effective cleaning. If flow is a concern, another option for increasing turbulence would be the addition of hydrogen peroxide to the caustic solution. Hydrogen Peroxide creates oxygen bubbles which aid in mechanical agitation. Because it is unstable in caustic solutions, be sure to add hydrogen peroxide as the solution is heating up and circulating though the CIP circuit.
Efficiencies. For those brewhouses that run 24 hours a day, efficiency of the wort chiller usually dictates the cleaning regiment. As the heat exchanger fouls up, the ability for heat to transfer across the plates is reduced increasing transfer time from brewhouse to fermenter. Many brewhouses are designed to recapture the heat from the wort by sending brew water through the heat exchanger and thereby preheating the water for the next brew. Depending on water hardness, minerals can drop out of solution quickly and deposit on the plates as the water quickly adsorbs the heat. For this reason, the water side of the heat exchanger should be routinely descaled using a Pass ECNTM acid or Guard 200TM solution. Periodically, pull the plates apart to inspect. Remember to check with your equipment manufacturer or supplier before disassembling and be sure to have spare gaskets on hand in case any are damaged when pulling apart the plates. Replace any gaskets that have cracks or show signs of wear- these areas could be harborage areas for beer spoilers.
Cleaning and preventative maintenance on wort chillers are important for efficiency, beer quality, and your brewery’s bottom line. My next topic in this series will be passivation of brewery equipment. Until then, stay safe and keep brewing!
Food Quality Specialist – ProActive Solutions USA
Steve has over 10 years of leadership experience in the brewing industry providing expertise in operations, quality management, logistic planning, and product development. As a former brewmaster, his knowledge and experience in CIP systems, sanitation, and process improvement are rooted in his passion for crafting high quality beer. Degree from University of Wisconsin- La Crosse in Biology.
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