Abstract: Disclosed are methods for the production of light stable hop products, useful for the brewing of beer or ale to be stored in clear or green glass containers, which beer or ale will not develop objectionable flavor as a result of exposure to light. Light stable hop products are prepared by double extraction of liquid/supercritical CO2 extracted hop solids with ethanol to remove alpha/iso-alpha-acids. Such alpha/iso-alpha-acids may be further removed from the ethanol extraction filtrate obtained in the double extraction process by subjecting such filtrate to an ion exchange medium, or precipitation by a metal ion, heavy metal ion, or alkali metal ion, or hydrogenation to provide an alpha/iso-alpha-acids free filtrate which may be added to the light stable double extracted hop solid residues obtained in the initial double extraction process.

Abstract: Disclosed are methods for the production of light stable hops, useful for the brewing of beer or ale to be stored in clear or green glass containers, which beer or ale will not develop objectionable flavor as a result of exposure to light. Light stable hops are prepared by double extraction of liquid/supercritical CO2 extracted hop solids with ethanol to remove alpha/iso-alpha-acids. Such alpha/iso-alpha-acids may be further removed from the ethanol extraction liquor obtained in the double extraction process by subjecting such liquor to an ion exchange medium, or precipitation by a metal ion, heavy metal ion, or alkali metal ion, to provide an alpha/iso-alpha-acid is free extraction liquor which may be added to the light stable hops residue obtained in the initial double extraction process.

Abstract: Disclosed are methods for the production of light stable hops, useful for the brewing of beer or ale to be stored in clear or green glass containers, which beer or ale will not develop objectionable flavor as a result of exposure to light. Light stable hops are prepared by double extraction of liquid/supercritical CO2 extracted hop solids with ethanol to remove alpha/iso-alpha-acids. Such alpha/iso-alpha-acids may be further removed from the ethanol extraction liquor obtained in the double extraction process by subjecting such liquor to an ion exchange medium, or precipitation by a metal ion, heavy metal ion, or alkali metal ion, to provide an alpha/iso-alpha-acids free extraction liquor which may be added to the light stable hops residue obtained in the initial double extraction process.

Abstract: Disclosed are methods for the production of light stable hops, useful for the brewing of beer or ale to be stored in clear or green glass containers, which beer or ale will not develop objectionable flavor as a result of exposure to light. Light stable hops are prepared by double extraction of liquid/supercritical CO2 extracted hop solids with ethanol to remove alpha/iso-alpha-acids. Such alpha/iso-alpha-acids may be further removed from the ethanol extraction liquor obtained in the double extraction process by subjecting such liquor to an ion exchange medium, or precipitation by a metal ion, heavy metal ion, or alkali metal ion, to provide an alpha/iso-alpha-acid is free extraction liquor which may be added to the light stable hops residue obtained in the initial double extraction process.

Abstract: Disclosed are methods for the production of light stable hop products, useful for the brewing of beer or ale to be stored in clear or green glass containers, which beer or ale will not develop objectionable flavor as a result of exposure to light. Light stable hop products are prepared by double extraction of liquid/supercritical CO2 extracted hop solids with ethanol to remove alpha/iso-alpha-acids. Such alpha/iso-alpha-acids may be further removed from the ethanol extraction filtrate obtained in the double extraction process by subjecting such filtrate to an ion exchange medium, or precipitation by a metal ion, heavy metal ion, or alkali metal ion, or hydrogenation to provide an alpha/iso-alpha-acids free filtrate which may be added to the light stable double extracted hop solid residues obtained in the initial double extraction process.

Abstract: Unsaturated organic compounds, in particular .alpha.-acids and .beta.-acids, are purified prior to hydrogenation by mixing them with an adsorbent capable of adsorbing catalyst poisons, preferably activated carbon, and separating the adsorbent containing the catalyst poisons to recover the thus purified unsaturated organic compounds. A significant reduction in the use of hydrogenation catalyst is realized.

Abstract: Tetrahydroiso-.alpha.-acids are prepared from iso-.alpha.-acids metal salts by hydrogenating the salts in a reaction solvent of a lower alkanol containing about 5% to about 20% w/w water and in the presence of up to about 5-50 psig hydrogen and a hydrogenation catalyst at about 30.degree.-50.degree. C. to form tetrahydroiso-.alpha.-acids.