Caustic Soda
Caustic soda, also known as sodium hydroxide, is a powerful alkaline cleaner that effectively dissolves organic matter. It is commonly used for cleaning brewhouse vessels, fermenters, and plate heat exchangers. Caustic soda dissolves easily in water and can be used in hot or cold formulations. However, it should be handled with care as it can cause severe chemical burns.
The raw, dry flakes of caustic soda are the cheapest option, but they are not ideal for brewing. These flakes are rough and can potentially damage equipment components and gaskets. In addition, working with dry flakes is difficult, and the dust can be harmful if inhaled or comes into contact with the eyes or skin. In brewing, caustic soda is most commonly used in liquid form with additives to enhance cleaning, reduce foaming, and protect various materials.
For hot side equipment, it is best to use caustic soda at high temperatures (up to 80℃) with a concentration of about 1% caustic soda to water. In cases of heavily soiled equipment, the concentration can be increased to around 1.5%. For fermenters, it can be used at lower temperatures, but it is generally more effective when used hot or at least warm. Also, note that caustic soda is neutralized by carbon dioxide (CO2), so it is important to fully vent and rinse fermenters before proceeding with the caustic wash for optimal results.
When cleaning with caustic soda, it is recommended to recirculate it through the vessels using a spray ball to ensure thorough cleaning of the interior surfaces. A weaker solution (around 0.3 – 1%) can also be left in pipes and heat exchangers to soak and break down stubborn residue. To clean the heat exchanger, it should be recirculated (preferably in the opposite direction of the beer flow) with a filter to capture any solids. For best results, recirculate the solution in vessels, pipelines, heat exchangers, etc., for 30 to 60 minutes.
Peracetic Acid
Peracetic acid is a potent disinfectant and sanitizer commonly used in breweries to sanitize equipment. It can be used in higher concentrations (up to 1% acid to water) to eliminate stubborn bacterial and fungal infections. However, it is typically utilized as a non-rinse sanitizer at concentrations of around 0.1% acid to cold water. It is recommended to recirculate for approximately 30 minutes for optimal results.
No-Rinse Sanitizer
A safe and convenient no-rinse sanitizer is essential in a brewery and serves various purposes. This sanitizer is made from food-grade phosphoric acid mixed with common detergent and cosmetic agents, enabling it to sanitize surfaces and equipment effectively.
It can be used to sanitize bottles and packaging equipment since it does not break down into oxygen like peracetic acid. Additionally, having a spray bottle filled with this sanitizer is useful for sanitizing gaskets and equipment before use.
Phosphoric/Nitric Acid
This acid mixture can be employed to passivate stainless steel vessels, but it is most commonly used to remove beer stone and other mineral deposits. It does not need to be used frequently, typically only once or twice a year, and thorough rinsing is necessary.
To remove beer stone deposits from brewhouse vessels, a mixture of 1% acid to water should be used at temperatures between 60-70℃. Recirculate the solution for approximately 15 minutes. This mixture can also be run through the pipework and heat exchanger.
For passivating fermenting vessels and other stainless steel equipment, use a mixture of 0.5% – 1.5% acid at room temperature and recirculate for around 15 – 20 minutes. Rinse thoroughly after cleaning.
