Stabilization of fermented beverages

1. A separation matrix comprising,

a porous solid support, comprising a polysaccharide selected from the group consisting of agarose, agar, cellulose and dextran, and

a plurality of polyvinylpyrrolidone (PVP) polymer chains covalently attached to said solid support,

wherein the separation matrix comprises 0.50-4.0 micromoles vinylpyrrolidone monomer residues per mL matrix;

wherein said polyvinylpyrrolidone polymer chains are vinylpyrrolidone homopolymer chains or copolymer chains comprising less than 2 mol % negatively charged monomer residues and

wherein the separation matrix comprises 0.5-0.8 g polyvinylpyrrolidone polymer per g dried matrix.

2. The separation matrix of claim 1 , wherein said polyvinylpyrrolidone polymer chains comprise less than 1 mol % negatively charged monomer residues.

3. The separation matrix of claim 1 , wherein said polyvinylpyrrolidone polymer chains comprise up to 30 mol % positively charged monomer residues.

4. The separation matrix of claim 1 , wherein said porous solid support comprises particles having an average diameter of 10-500 micrometers.

5. The separation matrix of claim 1 , wherein said porous solid support has a porosity of 80-98%.

6. The separation matrix of claim 1 , wherein a plurality of said polyvinylpyrrolidone polymer chains are each covalently linked to said solid support via a single linking moiety.

7. The separation matrix of claim 6 , wherein said single linking moiety comprises an ether-linked C3 chain.

8. The separation matrix of claim 1 , comprising 0.6-0.8 g polyvinylpyrrolidone polymer per g dried matrix.

9. The separation matrix of claim 1 , comprising 0.7-3.0 micromoles vinylpyrrolidone monomer residues per ml matrix.

10. The separation matrix of claim 1 , comprising less than 5 micrograms/g carbon leachables.

11. A method for stabilizing a fermented beverage, comprising the steps of:

a) providing a column packed with the separation matrix of claim 1 ; and

b) passing said beverage through said column and recovering a flow-through of the column as a stabilized beverage.

12. A method of manufacturing the separation matrix of claim 1 , said method comprising the steps of:

a) providing a porous solid support comprising at least 5 micromole/ml radical-reactive moieties;

b) contacting said support with a monomer composition wherein at least 70% of the monomers in said monomer composition is N-vinyl pyrrolidone;

c) initiating a free radical polymerization to form a matrix having polyvinylpyrrolidone polymer chains covalently attached to the support, and;

d) washing said matrix.

13. The method of claim 12 , wherein said radical-reactive moieties are C═C double bonds.

14. The method of claim 12 , wherein step a) comprises either i) providing a divinylbenzene copolymer support or ii) reacting a hydroxyfunctional support with an allyl halide or allylglycidyl ether.

15. The method of claim 14 , wherein step c) is performed with the support suspended in an aqueous solution comprising N-vinyl pyrrolidone and 0.05-3 mol/l of a salt.

16. The separation matrix of claim 1 , wherein the polysaccharide is agarose.

17. A method for stabilizing a fermented beverage, comprising the steps of:

a) providing a column packed with a separation matrix comprising,

a porous solid support, comprising a polysaccharide selected from the group consisting of agarose, agar, cellulose and dextran, and

a plurality of polyvinylpyrrolidone polymer chains covalently attached to said solid support,

wherein the separation matrix comprises 0.50-4.0 micromoles vinylpyrrolidone monomer residues per mL matrix, wherein said polyvinylpyrrolidone polymer chains are vinylpyrrolidone homopolymer chains or copolymer chains comprising less than 2 mol % negatively charged monomer residues and wherein the separation matrix comprises 0.5-0.8 g polyvinylpyrrolidone polymer per g dried matrix; and

b) passing said beverage through said column and recovering a flow-through of the column as a stabilized beverage.

18. The method of claim 17 , further comprising the steps

c) of regenerating the column with a regeneration solution and;

d) of repeating steps a)-c) at least twice.

19. The method of claim 18 , wherein said regeneration solution comprises 0.1-2 M NaOH.

20. The method of claim 17 , wherein in step b) the residence time of the beverage in the column is 2 min or less.

21. The method of claim 17 , wherein the fermented beverage is beer.

22. The method of claim 21 , wherein the stabilized beverage in step b) has a chill haze of less than 25% of the chill haze for the beverage before passage of said column.

23. The method of claim 17 , wherein the polysaccharide is agarose.