A method of forming solid beads, the method comprising: Providing a first liquid comprising a solute and a solvent Forming liquid droplets of the first liquid Contacting 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.