liquid phase closer to the top of the solution and increases the solute concentration in the still liquid solution the high concentration of solute can then form a solid mass that can inhibit the flow of gasses therethrough in a worse case the solute forms an amorphous solid that is nearly impermeable and prevents sublimation of the frozen solvent these layers of concentrated solute can inhibit the sublimation of the frozen solvent and may require use of higher drying temperatures and or longer drying times disclosed herein is an apparatus for and method of freezing a material e g for subsequent lyophilization that can prevent the formation of these layers and thereby provide efficient sublimation of the frozen solvent the lyophilization or freeze drying of solutes is the sublimation of frozen liquids leaving a non subliming material as a resultant product herein the non subliming material is generally referred to as a solute a common lyophilization procedure involves loading a lyophilization chamber with a container that contains a liquid solution of at least one solute the liquid solution is then frozen after freezing the pressure in the chamber is reduced sufficiently to sublime the frozen solvent such as water from the frozen solution the lyophilization device or chamber is adapted for the freeze drying of samples in containers by including at least one tray for supporting the container and means for reducing the pressure in the chamber e g a vacuum pump many lyophilization devices and chambers are commercially available with reference to fig1 3 the lyophilization chamber includes a heat sink 101 that facilitates the lowering of the temperature within the chamber the heat sink 101 includes a heat sink surface 102 that is.