Patent GB-981715-A (GB)
Title: A method for the reduction of haze in beer
IPC: C12H1/00
Filed: 1963-03-18
Abstract: A finely powdered ground silica gel being coarse-porous to medium-porous, having a surface area of 200 to 600 m.2/g., a pore volume of 0.5 to 1.5 ml./g. and a pore diameter of 40 to 180 <\>rA, the silica gel having been ground to such a degree that at least 75% (preferably at least 90%) by weight of the particles of the ground silica gel passing through a sieve of 44 microns mesh size (325 A.S.T.M. standard mesh) is used in the treatment of beer to reduce haze (see Division C6).  In order to secure a desired pH, the silica gel may be subjected to treatment with acid, which acid is thereafter washed out with water, and the silica gel is then dried; pH values between 4.0 and 8.0 taken in a 5% suspension in distilled water, are preferred.  The silica gel particles are stated to absorb in addition to the haze-forming compounds certain micro-organisms in the beer and the substances upon which the yeast and bacteria in the beer feed, provided the silica gel is used in sufficient amounts (more than approximately 50 g./ml. Specification 938,153 is referred to.ALSO:The reduction of haze in beer is accomplished by admixing with the beer a finely powdered ground silica gel being coarse-porous to medium-porous, having a surface area of 200-600 m.2/g., a pore volume of 0.5-1.5 ml./g. and a pore diameter of 40-180 <\>rA, at least 75% (preferably at least 90%) by weight of the particles of the ground silica gel passing through a sieve of 44 microns mesh size (325 A.S.T.M. standard mesh), and then filtering off the silica gel from the beer.  A filter aid may additionally be used.  In order to secure a desired pH, the silica gel may be subjected to treatment with acid, which acid is thereafter washed out with water, and the silica gel is then dried; pH values between 4.0 and 8.0 taken in a 5% suspension in distilled water, are preferred. The silica gel particles are stated to absorb in addition to the haze-forming compounds certain micro-organisms in the beer and the substances upon which the yeast and bacteria in the beer feed, provided the silica gel is used in sufficient amounts (more than approximately 50 g./ml.).  Under preferred conditions of operation described, beer is brought to the desired final degree of attenuation in the fermentation vessel, volatile substances such as hydrogen sulphide and mercaptans are removed by washing the beer with carbon dioxide, and the non-volatile substances such as tannic compounds disturbing the flavour are removed and haze formation is reduced by treatment with sufficient of the silica gel.  The washing with carbon dioxide may be effected either by fermenting under counter-pressure or carbonizing the beer after the main fermentation, and thereafter relieving the pressure. Tannin or enzymes may be added to the beer to precipitate a part of the higher molecular weight protein therein.  Specification 938,153 is referred to.ALSO:Beer haze is reduced by admixing with the beer a finely powdered ground silica gel which is coarse-porous to medium-porous, having a surface area of 200-600 m.2/g., a pore volume of 0,5-1,5 ml./g. and a pore diameter of 40-180  , at least 75% (preferably at least 90%) by weight of the particles of the ground silica gel being capable of passing through a sieve of 44 microns mesh size (325 A.S.T.M. standard mesh), and then filtering off the silica gel from the beer.  A filter aid may additionally be used.  In order to secure a desired pH, the silica gel may be subjected to treatment with acid, which acid is thereafter washed out with water, and the silica gel is then dried; pH values between 4,0 and 8,0, taken in a 5% suspension in distilled water, are preferred.  The silica gel particles are stated to absorb in addition to the haze-forming compounds certain micro-organisms in the beer and the substances upon which the yeast and bacteria in the beer feed, provided the silica gel is used in sufficient amounts (more than approximately 50 g./ml.).  Under the preferred conditions of operation described, beer is brought to the desired final degree of attenuation in the fermentation vessel, volatile substances such as hydrogen sulphide and mercaptans are removed by washing the beer with carbon dioxide, and the non-volatile substances such as tannic compounds disturbing the flavour are removed, and haze formation is reduced by treatment with sufficient of the silica gel.  The washing with carbon dioxide may be effected either by fermenting under counter-pressure or carbonizing the beer after the main fermentation, and thereafter relieving the pressure. Tannin or enzymes may be added to the beer to precipitate a part of the higher-molecular-weight protein therein.  Specification 938,153 is referred to.