GB887796A - Process for clarifying beverages - Google Patents

Abstract

The Specification discloses a method for preparing N-vinyl-2-oxazolidinone polymers: 50 g. pure N-vinyl-5-ethyl-2-oxazolidinone, 50 g. pure N-vinyl-5-methyl-2-oxazolidinone, 1 g. a ,a 1-azobis -isobutyronitrile and 500 g. of dry ethanol were heated under reflux at 78 DEG C. for 10 hours; at least 98% conversion of monomers to copolymer product was achieved. The copolymeric product, which contained about equal weight proportions of the polymerized monomers, was isolated in dry diethyl ether as a white powder having a density of about 1,24 g. per c.c., a molecular weight p of about 13,000 and a "cloud" point in water of 26 DEG C.ALSO:Beverages, such as beer, spirits, wine, tea and fruit juice, are clarified and stabilized against hazing by adding sufficient of an N-vinyl-2-oxazolidinone polymer to coagulate and precipitate the haze-inducing ingredients and, if desired, the precipitate formed is removed, as by filtration. Poly-N-vinyl-2-oxazolidinone, poly - N - vinyl - 5 - ethyl - 2 - oxazolidinone, poly - N - vinyl - 5 - methyl - 2 - oxazolidinone and copolymers of N-vinyl-5-ethyl-2-oxazolidinone and N - vinyl - 5 - methyl - 2 - oxazolidinone containing at least about 1% of either monomer and preferably 60-80% of the ethyl monomer are suitable. A proportion of 0.001 to 1%, preferably 0.001 to 0.02%, of the polymer or copolymer is added to the beverage; with beer, the addition can be made when the beer is being racked down from the fermenters, during storage, or in the mashing stage. Although the treatment may be accomplished at any moderate temperature, in cases where heating of the beverage to temperatures in excess of chilling temperatures is undesirable, e.g. with beer, the beverage is treated at a temperature beneath the cloud-point of the polymer or copolymer, which can be in the range of below 4 DEG C. up to 40 DEG C., and thereafter the beverage is warmed to a temperature above the cloud-point. Examples are directed to the clarification of apple juice, raw and finished beer, wine, sweetened grape juice and prune juice; the results of some examples are depicted graphically, Figs. 1 to 4 (not shown).