A method of forming solid beads, the method comprising:Providing a first liquid comprising a solute and a solventForming liquid droplets of the first liquidContacting the liquid droplets with a second liquid so as to cause the solvent to exit the droplets, thus forming solid beads,the solute comprising a polymer, the concentration of polymer in the first liquid being at least 7% w/v.,the solubility of the solvent in the second liquid being at least 5 g of solvent per 100 ml of second liquid.