There are three basic standards of cleaning
- Physically Clean – visually clean
- Chemically Clean – clean to a standard where anything coming into contact with the surface suffers no chemical contamination.
- Microbiologically Clean – clean and sterile so that there is no physical or micro-biological contamination.
This table outlines the standard required for various parts of the brewing process:
|Process||Plant||Soil Type||Cleaning Procedure||Cleaning Criteria||Chemicals|
|Milling||Mills and Rollers||Dust||Manual||Physically clean||None|
|Mashing||Mash Tun||Particulate sugar, scale, tannin||Manual or CIP||Chemically clean||Detergent|
|Boiling||Copper||Starch, sugar, hop residues, scale, tannins||Manual or CIP||Chemically clean||Detergent|
|Cooling||Para-flow||Particulate protein scale||Manual, CIP or both||Micro-biologically clean||Detergent & Sanitiser|
|Fermentation||F.V.’s||Yeast, Tannin, Sugar, Scale, Protein, Oxidation products||Manual or CIP||Micro-biologically clean||Detergent & Sanitiser|
|Conditioning||Closed Vessels||Yeast, Protein, Scale||CIP||Micro-biologically clean||Detergent & Sanitiser|
|Packaging||Casks||Yeast, Protein, Scale||CIP||Micro-biologically clean||Detergent & Sanitiser|
|Cellar||Beer lines||Yeast, Protein, Scale||CIP||Micro-biologically clean||Detergent & Sanitiser|
The choice of cleaner employed will be dependent upon the nature of the deposits found in a particular environment and on the cleaning criteria. Generally speaking organic deposits such as proteins, gums, yeast, sugars and hop residues are most efficiently removed by caustic based cleaners, whilst inorganic scale is removed by acidic cleaners. The materials of construction of the plant are also critical, caustic soda based cleaners for example being aggressive to Aluminium.