Chapter 20

Brewery Cleaning And Sanitation

Cleaning Detergents

Cleaning detergents can contain several active ingredients, including oxidizing agents such as hydrogen peroxide, acids and bases (alkaline chemicals), surfactants that break down dirt and greasy residues, and chelating agents. Detergents also contain sequestrants (metal chelating agents), which are important when using hard water. Generally, increasing the concentration beyond recommended levels provides little additional benefit and is not cost effective. Cleaning detergent requirements vary according to the area and equipment to be cleaned. There are literally hundreds of detergent mixtures available that are specifically tailored to the needs of the brewery.

Alkaline-Based Detergents

Alkaline detergents are most effective in removing organic substances such as sugars (carbohydrates), fats, oils, and proteins encountered in beer brewing. The most commonly used detergents include alkaline-based detergents such as sodium hydroxide or potassium hydroxide. Other alkaline-based detergents can be used in a brewery. Where the relative amount of organic material is not heavy, mild alkalis such as sodium carbonate or trisodium phosphate find application.

Sodium Hydroxide

Of the cleaning agents, sodium hydroxide (NaOH), otherwise known as caustic soda, is widely used in breweries worldwide. Its effectiveness in dissolving proteinaceous soils and fatty oils by saponification is virtually unsurpassed. Sodium hydroxide is an acutely excellent emulsifier too. It is often used at concentrations of 2 to 5 percent and temperatures of 70 to 90 degrees C (158–194°F).

Potassium Hydroxide

Potassium hydroxide (KOH), otherwise known as caustic potash, is used as a cleaning agent and sanitizer in breweries, mainly to clean the insides of tanks from biofilms of bacteria and yeast. As a strongly basic inorganic compound, it works effectively to kill acidic beer organisms that are adapted to low pH environments. It is similar to and just as effective as sodium hydroxide, which is the most commonly used cleaning agent in breweries today.

Sodium Carbonate

Sodium carbonate is also known as soda ash. Sodium carbonate is the most common alkaline chemicals found in cleaning products, being very effective in dislodging heavy deposits from tank walls or removing greasy residues. It’s a good cleaning agent for many surfaces, but should not be used to clean barrels because it leaches key oak compounds.

Sodium Percarbonate

The key difference between sodium carbonate and sodium percarbonate is that sodium carbonate is a single molecule whereas sodium percarbonate is an adduct of sodium carbonate and hydrogen peroxide.

Trisodium Phosphate

Trisodium phosphate (TSP) is a white crystal that forms an alkaline solution when mixed with water. Trisodium phosphate is non-toxic, inexpensive, and has a pH of 12 to 14 in solution.

Detergent Compound Terminology

Detergents are agents made up of a variety of compounds. To further understand the properties of detergents, the following terms are important:

Acid-Based Detergents

Acid detergents, especially blends of acids such as phosphoric, nitric, sulfuric, and sulfamic, are mostly used for scale/mineral deposit removal and prevention. Acidic detergents are employed by many breweries for regular cleaning of the bright beer tanks, filter buffer tanks, maturation tanks and associated lines, and inside of kegs. They are less frequently used for cleaning beer filters, centrifuges, fermentation tanks, and fillers (bottle and can). Acidic detergents are not normally used for cleaning brewhouse vessels because of the proteinaceous nature of the soils, which are better removed by caustic detergents.

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