Cleaning Substances For The Brewery

Caustic Soda

Caustic soda (sodium hydroxide) is an aggressive alkaline cleaner that dissolves organic matter, making it ideal for cleaning brewhouse vessels, fermenters, and the plate heat exchanger. It dissolves easily in water, and formulated versions can be used hot or cold. It can cause severe chemical burns and must be handled with care.

The cheapest type is the raw, dry flakes, however this isn’t ideal for brewing as it’s quite rough, and can damage components and gaskets. Aside from that, it’s difficult to work with, and the dust can damage the respiratory system if breathed in, as well as eyes and skin. In brewing, it’s most commonly used in a formulated liquid form, with various additives added to improve cleaning, reduce foaming, and protect various materials.

It’s best used hot (up to 80℃) for hot side equipment, typically at a concentration of around 1% caustic to water, though for badly soiled equipment you can increase this to around 1.5%. For fermenters it can be used at colder temperatures, but is generally more effective when used hot or at least warm. It’s worth noting that caustic soda is neutralized by carbon dioxide (CO2), so be sure to fully vent and rinse your fermenters before proceeding with the caustic wash for best results.

When cleaning with caustic, it’s good to recirculate it through vessels via the spray ball to ensure complete cleaning of the interior. A weaker solution (around 0.3 – 1%) can also be left in pipes and in the heat exchange to soak, breaking down stubborn matter. To clean the heat exchanger, it should be recirculated (preferably in the opposite direction to the flow of beer), using a filter to catch any solids. For best results, recirculate in vessels, pipelines, heat exchange, etc. for 30 to 60 minutes.

Peracetic Acid

Peracetic acid is a strong disinfectant and sanitizer that is frequently used by breweries to sanitize their equipment. In higher concentrations (up to 1% acid to water), it can be used to kill off stubborn bacterial and fungal infections. However, it’s typically used as a non-rinse sanitizer, at concentrations of around 0.1% acid to cold water. For best results, recirculate for around 30 minutes.

No-Rinse Sanitizer

Safe, no-rinse sanitizer is useful to have around the brewery and has several applications.  Made from food-grade phosphoric acid mixed with various agents common in detergents and cosmetic, it sanitizes surfaces and equipment.

It can be used for sanitizing bottles and packaging equipment, as unlike peracetic acid, it won’t break down into oxygen. Otherwise, it’s good to have a spray bottle which can be used for sanitizing gaskets and equipment prior to use.

Phosphoric/Nitric Acid

This acid mix can be used to passivate stainless steel vessels, but is most commonly used to remove beer stone and other build-ups of mineral deposits. It doesn’t have to be used frequently, perhaps once or twice a year, and must be rinsed thoroughly.

On brewhouse vessels, use around a 1% mix of acid to water, between 60-70℃ to remove beer stone deposits. Recirculate for around 15 minutes. It can also be run through the pipework and heat exchanger.

For passivating fermenting vessels and other stainless steel vessels, use a 0.5% – 1.5% mix at room temperature and recirculate for around 15 – 20 minutes. Rinse thoroughly.