The RIMS Process

Many of these steps are common to most mashing procedures, not just RIMS systems:

  1. Heat up strike water while milling grain.
  2. Close the outlet valve to your mash/lauter tun and insert your false bottom.
  3. "Underlet" the false bottom with the hot water. Underletting is the process of adding just water to your mash tun until the surface if the water is above your false bottom. This helps float the grains above your false bottom so the smaller kernels don't clog the holes and create a stuck mash situation.
  4. Once water is above false bottom, begin doughing in your grain as you normally would. Once completely doughed in, add a little extra water, about 2 quarts, to make up for the volume that will be in the pump and plumbing during recirculation.
  5. Open valve from your mash/lauter tun to fill pump and plumbing with liquid. Magnetically driven pumps require liquid for lubricant, so you should avoid running them dry.
  6. I have another ball-valve located on on the outlet side of the heating element that I use to control the speed of recirculation. I partially close down this valve before turning the pump on because I do not want to pump full speed. I start very slow and increase to between ¾ and 3 gallons per minute, just enough so that it is flowing smoothing but not so fast that it might mix with the air and cause Hot Side Aeration (more on this later). If you pump too fast you may also compact your grain bed, but you can also pump too slow and scorch your wort as it flows too slowly over the heating element.
  7. Once the pump is primed, turn it on. You will notice that some grains get pumped through, but soon clear. The wort is milky/hazy from starch content.
  8. Here is where the PID takes over. I just enter the desired mashing temperature on the digital display and the PID ramps to that temp and then holds it there automatically and is completely hands free. If you are manually controlling the power to your element, then turn up heat as necessary to either boost to desired starting point or to maintain temperature. Hold at this temperature according to recipe. When I do simple one-temperature mashes (~150°F) with well modified malt my wort becomes noticeably clear of starch haze in as quick as 10 or 15 minutes. Stepped temperature mashes, such as ones that include a protein rest at about 120°F don't clear as quickly, but they do clear quickly once the temperature is boosted up into the saccharrification temperatures. This makes sense if you think about.
  9. If recipe calls for a stepped mash, then boost temp to next setting and hold. With the PID, this involves just entering in a new set point temperature. The PID will then ramp to and then hold that temp. Expect to increase the temperature of your wort between 1°F and 1.5°F per minute, depending on wort volume, wattage of your heater, and the insulation on your mash tun.
  10. When mash is complete, there is no need to recirculate to clear during sparging since it should already be crystal clear. Just sparge as you normally would into a waiting container. Or, you can even sparge into your boiling kettle using your RIMS pump. Simply pickup your returned-wort tubing and move it from the mash tun into the boiling kettle. Start your sparge and then gently open the ball valve so that you slowly begin to pump into your boiling kettle. The tricky part is getting the pumping rate to match your sparge rate.