Pumping can be either the most glorious or most heinous activity on a RIMS system. Lot’s of things can go wrong, but it is so convenient and wonderful when it all goes right. The Brew Magic
Missing from the photo above is Valve 1, which is from the BK to the chiller/fermenter, and the Dump Valve, located below the control box containing the pump. Understand the system as it is designed and how liquid flows is managed. Carefully read the instructions for the official processes.
Perhaps this is more easily defined by the traditional steps as you brew:
1.) Mash-in/Dough-in: Hot water needs to flow from the HLT, through the Heat Exchanger and Pump, into the MLT. You should allow gravity to feed the MLT from the bottom till it covers the false bottom, and then pump liquor into the MLT from the top. Watch your fingers if you are direct firing either kettle!
Gravity Feed Liquor: V2 – closed, V3 – open, V5 – open, V4 open – let water rise into the MLT above the false bottom
Pumping Liquor: V2 – closed, V3 – open, V4 – closed, V5 – closed and opened after pump engaged
2.) Mash Recirculation: Wort is pumped from the bottom of the MLT, through the Heat Exchanger and Pump, to the top MLT inlet and into the hose to create a gentle whirlpool. This also requires control with Valve 5.
Mash Recirculation: V2 – closed, V3 – closed, V4 – fully open, V5 – closed and opened after pump engaged. Use V5 for flow control to maintain proper flow rate above the mash.
3.) Sparge: Hot sparge water is pumped from the HLT to the MLT at a very slow rate, maintaining about 1-2 inches of liquid at the top of the mash, while the MLT drains slowly into the boil kettle. Patience, control and valve configuration is key to a successful sparge.
Fly Sparge: V2 – open, used to maintain rate of draining during sparge, V3 – open, V4 – closed, V5 – closed and opened when pump engaged, used to control flow rate to top of mash. This should take between 45-60 minutes to complete.
Batch Sparge: V2 – open, fully drain the MLT. All other valves closed. After draining, close V2. Use “Mash-In” procedure to pump over the exact sparge volume to the top of the mash. Stir hard to re-suspend the entire mash for a couple of minutes. Then use “Mash Recirculation” procedure to reset mash and clear the wort (vorlauf). This usually takes about 10 minutes. Then turn off pump and close all valves – fully open V2 and drain. You may wish to do this in 2 equal steps.
All of these processes can be interrupted when air enters the plumbing system, causing the pump to lock up. This is FAR more common than grains plugging up the pump, and figuring out where the air maybe coming into the plumbing can be maddening. So it is critical to maintain the prime on the pump – that is keeping the pump flooded at all times. Air can enter the system anywhere a valve is open to the air…
- Valve 2 – MLT to BK: This should remain closed at all times until you need to sparge or drain. If Valve 4 is open and recirculating, the vacuum created will draw air into the plumbing causing air locking. If the dip tube is submerged in the BK, it can actually pull wort back into the system.
- The HLT dip tube: When you are pumping, a vacuum is created drawing the liquor out of the kettle. When the water is near or below the bottom of the tube, it can suck in air creating a lock. I always try to keep at least 1 gallon of water over the bottom (roughly 1/2 the height of the dip tube) to prevent this. Any jarring or sloshing when the water is low can create the same effect.
- The Mash: During mash-in, air is trapped between the grains of malt. It is important to NOT recirculate until all of the grain is thoroughly mixed and hydrated. If you gravity filled the MLT to above the false bottom, and pumped in the remaining water – then most of the air will be eliminated.
- Stuck Mash: RIMS users experience a stuck mash during recirculation usually before sparging. If you pump too fast (Valve 5 controls the speed of the flow), you can create a vacuum under the mash and compact it. This requires you to stop pumping (and direct fire) and using a mash paddle breaking up the mash bed. I would also suggest keeping some rice hulls handy to help the mash filtration capabilities – you can stir them in well at this time. Then, open Valve 4 with Valve 5 closed, start the pump and slowly open Valve 5. Let this run at 1/4 to 1/2 speed until the wort runs clear again, then determine if you can increase the flow rate. This happens often with large portions of rye or wheat in the grist. Avoid the temptation of opening and closing random valves to see if you can unstick it which can further complicate things!
- MLT inlet: This can be a bit frustrating as it is counter-intuitive. You should fully close Valve 5 before turning on the pump, then slowly open it. This prevents a potential siphon condition, pulling wort (and grains) from the top of the MLT backward into the pump. Remember there is a column of wort/liquor sitting above that valve and gravity will make it fall if there is no pressure pushing it up.
Using the dump valve, below the control box, can help free the air lock. Close all of the valves and open the HLT valve until wort and water streams from the dump valve. Close the dump valve and the HLT valve. Try the pump and slowly open Valve 5 and fully open Valve 4. You should see a solid stream of wort in the MLT.
Valve 5 is really your “gas pedal” in the system. I have found that the valve handle comes loose with usage and needs an occasional adjustment. It is simple to tighten up. You will often need to use Valve 5 while looking in the MLT to judge the flow rate. It is handy to have a small stool or stand that will allow access to both.
So this reads as fairly complicated and is a bit to grasp when learning to use the system. That said, it becomes second nature as you gain experience. Listen carefully to the pump – you will learn to know when it is struggling and need some adjustment. You can practice during a cleaning or rinse cycle, and create an air lock, and then determine how to solve it. Any of the scenarios above (except the mashing) will illustrate the problem and solution.
One final recommendation: Whenever a problem arises, immediately turn OFF all direct fire burners. A stuck mash can scorch and boiling wort can create gas bubbles that can lock the pump – and a fully open burner will cause this to happen very quickly. The surfaces also become extremely hot – making it hazardous to touch the frame or kettle plates. The gas valves operate so they are OFF when inline with the gas plumbing. Keep a spray bottle of water handy – you can cool off a handle or a tri-clamp with it if you have to un-assemble parts for a fix.
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I am not in any way associated with Sabco or the Brew Magic team, other than being an enthusiastic owner! These instructions do not replace the recommendations provided by Brew Magic on its websites or instruction materials. Please use these recommendations at your own risk…