In your home kitchen, when you produce some food you can simply wash up any dirty containers or utensils when you are finished. This isn’t always so simple in a larger scale manufacturing process. Manufacturers of liquid products such as dairy, beverages and sauces don’t dismantle pipework or vessels used in production, but instead use this pipework to circulate chemicals and water to clean the system with no dismantling necessary. This is called Clean In Place or CIP.

Why is it important?​

Effective cleaning is an important component in food safety and hygiene. Without thorough cleaning between production runs the manufacturing process could become contaminated with harmful bacteria and the food produced may fail food safety and quality standards. Failing to flush systems through before production resumes could result in chemical contamination.

When clean in place is carried out correctly there are effective controls in place to prevent cross-contamination of food and cleaning agents and it is a time efficient, and safe method of cleaning equipment. It may be used as part of the routine cleaning of equipment, or when switching equipment between producing different products.

How does it work?

In simple terms, a cleaning liquid is circulated through the production machinery using a cleaning circuit. In order to achieve the most effective clean, there needs to be an optimised balance between the mechanical force (pressure) of the flowing liquid, temperature, chemicals used, and the length of time that they are left to act. The temperature is usually set no higher than the temperatures needed in the manufacturing process to avoid altering the compositions of proteins, making them more difficult to remove.

Clean in place usually uses water to remove product residues, before using a series of cleaning solutions interspersed with water rinses. There are usually 5 stages to a complete clean in place cycle.

1. Before starting the cleaning process it is standard procedure to finish the production cycle by pushing any remaining product through the system with water. A pre-rinse with hot water at between 40 and 60°C is used to dissolve sugar and melt fat deposits in the machinery.
2. Organic debris such as fats and proteins are removed by circulating an alkali based detergent.
3. Next, a water rinse flushes out the alkali solution and any dissolved soiling.
4. An acidic detergent may be used next to dissolve and carry away mineral or limescale deposits. Depending on the manufacturing process this might not be required at every clean.
5. Another water rinse clears away the acidic detergent. The equipment should now be visibly clean.

Before restarting the production cycle, a sterilisation or disinfection cycle is usually used to reduce bacteria and other microorganisms to an acceptable level. This may be done with steam, hot water, or using chemical agents. If disinfecting chemicals are used, then a final rinse with water will be required before restarting food production. After the final rinse there should be only water left in the system, with no traces of cleaning agents so that when production starts back up there will be no contamination.

Sparkling pipes may not be what you think about when you are washing down your steak with a full bodied red, but it’s good to know that with Clean In Place, manufacturers have it in the can.