Preparation of light stable hops

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.

Description

CROSS REFERENCES TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. application Ser. No. 10 / 106,603 filed Mar. 26, 2002.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH [0002] Not applicable. BACKGROUND OF THE INVENTION [0003] 1. Field of the invention [0004] This invention relates to the treatment of hop solids which is the residue remaining after liquid or supercritical CO2 extraction, and produces a hop product which imparts not only hop flavor and mouthfeel indistinguishable from original whole hops, but also provides light stability and flavor variations in malt beverages. Such treated hop solids can contribute hop flavor and mouthfeel to beer with low bitterness. However, a residual amount of alpha / iso-alpha-acids, which causes light instability in finished malt beverages, is still present in the hop solids. The present invention is directed to the preparation of light stable hop products, containing little or no alpha / iso-alpha-acid, for providing hop fla...

AI Technical Summary

Benefits of technology

[0018] It is thus an advantage of the present invention to provide an inexpensive method for the preparation of light stable hops, which are useful in providing hop flavor and mouthfeel for brewed product to be packaged in clear, flint or green bottles. Such brewed product is found to be less subject to skunk flavor resulting from exposure to light over time.

to provide an inexpensive method for the preparation of light stable hops, which are useful in providing hop flavor and mouthfeel for brewed product to be packaged in clear, flint or green bottles. Such brewed product is found to be less subject to skunk flavor resulting from exposure to light over time.

Problems solved by technology

Such iso-alpha-acids are, however, susceptible to a photochemical reaction which produces “skunk”, an undesirable sulfur flavor characteristic resulting from the presence of 3-methyl-2-butene-1-thiol.

To integrate the full spectrum of hop flavor would thus require the addition of hop solids to the brew, but the hop solids have been found to contain trace amounts of alpha / iso-alpha-acids, which, due to lack of light stability, contribute to skunkiness in beer.

While this method does provide a brew having less bitterness but a comparable hop flavor to a brew prepared using whole hops, it does not fully address the issue of iso-alpha-acids present in the solid hop residue.

Since the solid hop residue is present in the brewing kettle, iso-alpha-acids are present in the final brew, potentially leading to an undesirable skunk flavor.

Such a method clearly adds complexity to the desired goal of providing a light stable form of hops.

However, a method for the production of light stable hops containing little or no alpha / iso-alpha-acids, which also imparts hop aroma and flavor to the brewing of beer equivalent to or comparable to the aroma and flavor attained from the use of conventional hops, has not previously been provided.