A method for reacting a plurality of materials in parallel within a reactor vessel having a plurality of reaction wells formed therein. Each of the reaction wells has an open end exposed to a common pressure chamber defined by the reactor vessel. The method includes opening a cover of the reactor vessel, inserting components into the reaction wells, closing the cover of the reactor vessel to create a sealed chamber, supplying a gas substantially above atmospheric pressure that reacts with the components within the reaction wells, and releasing pressure from the reactor vessel.