Table of Contents
What is beer filtration?
Filtration is not only used to clarify beer but also to purify it and make it sterile. Many processes in beer production focus on sterilization and purification, and filtration is one of them.
Beer Filtration Process
Clarification filtration is one of the most common types of filtration used in beer production, with the main purpose of removing suspended and particulate matter from the beer to make it appear clear. The main clarifiers include:
Clarification
- Silica Clay (Diatomaceous Earth): a porous mineral commonly used as a filtration medium. As the beer passes through the layer of diatomaceous earth, large particles of material are trapped in its interstices, making the beer clearer.
- Polymers: such as polyvinylpyrrolidone (PVPP) and polyacrylamide (PA). They adsorb and remove proteins and polyphenolic compounds from the beer, thus improving its stability and clarity.
- Purification shells: used for the removal of hop residues, due to their hard and porous structure they effectively filter large particulate matter.
- Clarification filtration is often achieved using filter media (e.g. filter cloths, filter paper, filter membranes), the fineness of which can be adjusted as required.
Sterile Filtration
Sterile filtration is used to ensure that the beer is sterile when it is bottled or canned. This step is critical because the presence of microorganisms can lead to spoilage of the beer or an uncontrolled fermentation process. Sterilization filtration uses microporous filters, usually 0.2 microns in size, which are large enough to filter out most yeast and bacteria.
Cold Stabilization
Cold Stabilization focuses on insoluble proteins and caseins that occur at low temperatures and can cause cloudiness in beer. Cold Stabilization removes these insoluble substances by allowing the beer to stand at a low temperature or by passing it through a filtration medium to ensure that the beer remains clear during cooling and storage.
Other Filtration Methods
In addition to the main filtration methods mentioned above, there are several other specific filtration techniques such as:
- Fine Filtration: the use of finer filtration media, e.g. 0.45-micron pores, to further improve the clarity and stability of the beer.
- Rotary Filtration: utilizes rotary filtration equipment, where pressure and rotary action are used to propel the beer through the filtration media, efficiently removing suspended matter.
The importance of beer filtration
Beer is a carbon dioxide-containing, low-alcohol beverage made by fermentation of brewer’s yeast with malt, rice, hops, and water as the main ingredients. Beer filtration removes impurities and microorganisms from beer that affect taste and quality. Beer produces some sediments during the brewing process, and if these sediments are not removed, the beer will become cloudy and taste bad.
Also, more important than the appearance and flavor of the beer is the quality of the beer. Beer filtration removes yeast and other microorganisms and prevents the beer from becoming contaminated. We all know that yeast is essential to beer brewing, but if there is yeast in the beer being sold, the beer can easily go bad and consumers are prone to health problems from drinking it. Filtered beer has no odor produced by bacteria and has a long shelf life.
Removal of turbid substances that have settled in the beer to be filtered: e.g. settled hop resins, proteins and polyphenolic compounds, dextran, calcium oxalate particles, yeast, etc.
- Remove or reduce the substances in the beer that will cause turbidity in the finished beer, such as high molecular proteins, polyphenols, and dextran.
- Remove or reduce yeast in beer. Remove microorganisms in beer that are effective microorganisms (e.g.: Lactobacillus, Polycoccus, Pectobacterium, Pasteurella, etc.)
- Improve the taste of beer, make the beer clear and transparent, shiny. Filtration of beer can make the color of beer more vivid and the liquor more clarified, which perfectly meets the consumer’s requirements for beer.