RIMS system (Recirculating Infusion Mash System)

The equipment, complete with Arduino

*RIMS tube disassembled

The RIMS tube is welded from 1.5" stainless tubing with tri-clover fittings. A thread for a standard water heater element is at bottom and a thermowell tube at top. (www.brewershardware.com) This guy does beautiful work in stainless steel


The heat element inside the RIMS tube is a large low-heat-density stainless steel water heater element, rated 240VAC, but running at 115 VAC to avoid scorching. After 3 batches, it's pristine with no scorching.

*RIMS controller face

Switches, indicator lamps, PID controller, digital thermometer, and Arduino and flow interlock and LCD display. The pump must be ON and flow either detected or over-ridden before current is allowed to pass to the heater. (www.sureelectronics.net for the PID)

*RIMS controller inside

Arduino circuit board at left showing connectors for hall-effect flow sensor and interlock relays. PID controller at top center. Since this picture, I've replaced the solid state relay with one on a larger heatsink. The Arduino program uses an interrupt response routine to increment a counter. The background process waits 2 seconds then scales the pulse count to liters per minute and updates the display and the flow interlock output.

*flow sensor

1/2" high-temperature hall-effect flow sensor gives roughly 80 pulses per second for 5 gallons per minute in this application. The LCD display is programmed to display liters per minute. (www.futurlec.com)

*assemble stand

Portable hinged stand to hold the RIMS tube and water pump.

*connect tube stand brace

Brace holds it square

*cooler to stand


*secure tube keepers


*attach QD hoses

The stainless cam-lock Quick-Disconnect hose connectors are easy to attach and don't leak. The silicone tubing handles high temperatures without stretching. Once the cooler is filled, open bottom valve to flush air from the lines and prime the pump. (www.bargainfittings.com)

*March hs809 pump

The motor and the food-grade pump housing are magnetically coupled. This pump is rated at up to 7.5 gallons per minute at up to 121C. I measure roughly 5GPM in this application with flow restrictions and 2 foot head. (www.austinhomebrew.com}

*ground clamp

Before attaching the pump or heater, tie the chassis to water-pipe ground. The RIMS tube is grounded through a welded lug to the power cord then to earth ground.

*plug-in pump

The outlet at right is controlled by the pump switch. The left outlet is controlled by the solid state relay, which passes current when the PID controller gives it a 12 volt signal. This signal only passes if the flow interlock circuit is driving the relay

*probe into thermowell

The type K thermocouple for the PID fits down the thermowell. An RTD sensor might be more accurate, but this probe and controller matches my reference thermometers within 1 degree F

*arduino flow fault

An Arduino mini was programmed to count Hall-effect flow sensor pulses, drive interlock and indicator relays, and display scaled flow or alarm state on the LCD screen

*liters per minute

The LCD displays flow in liters per minute. A four-tube copper manifold in the bottom and a three-leg sparge arm in the top of the cooler reduce flow very little.


 ***** Brewing with RIMS ***********



*dough-in temperature

About 2 hours after setting the PID to dough-in temperature, 9.5 gallons of water are ready for the grist.


After turning off the pump, add the grist and level the bed, then connect the sparge manifold, start pump, and set PID to desired mash temperature. Even with a 14 pound grist for no-sparge mashing, the flow rate through the manifold is still nearly 100 liters per minute

*sparge manifold

With the large area of three drilled arms, this manifold gives gentle flow to the top of the grain bed. Remaining underwater at all times, there is no aeration of hot wort.


The PID controller holds a very stable temperature. For a mash-out, set the controller to 168. the ramp-up from mashing temperature takes about ten minutes.

*mash-out temperature


*drain to boiler

With no-sparge mashing, the entire wort is drained at once. For batch or classic sparging, additional water (heated elsewhere) is added and drained through the grain bed to the boiler.

*all-grain brew

RIMS eliminates issues with mash temperature control. Since you can boil in any weather, winter brewing is now possible.

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