Introduction

The brewing system shown at right is a home-built machine for making beer.  In this part of the brewing process, various malted grains are mixed with water and the mixture, called “wort”, is held at different temperatures.  Depending on the type of beer being brewed, the wort is raised and held at different temperatures for specific time periods.  This process is called the “mash”.

Various techniques are used to perform the mash.  One technique is to use a Recirculating Infusion Mash (RIM) system. 

The RIM technique forms a grain bed, which is supported on a mesh. 

A pump recirculates the wort through a heater to maintain the pre-determined temperatures. 

The heater is manually controlled by dialing on the required temperature, and allowing a thermostat to control power to a heating element. 

An independent temperature sensor measures the actual temperature, and allows a computer to monitor the actual vs. the expected temperature.