RIMS or recirculating infusion mash system is a mash infusion system that either utilizes a pump to recirculate the fluid in the mash over a secondary heat source (outside of the mash tun) to maintain the mash temperature, or constantly recirculates the mash onto itself while direct heat is applied to the mash tun to regulate the temperature. The fluid is pumped at a rapid enough pace to keep the temperature of the mash at an equilibrium and prevents the wort from being scorched or overheated.