Compacting the Grain bed

LarMoeCur · Joined: 14 Feb 2015 Posts: 18

I've got about 40 batches under my Electric brewing belt. The one issue I have almost every batch is that grain bed gets pulled down on top of my false bottom. Afraid it's getting compacted.

My setup. 5/8" side dip tube intake is centered in kettle. False bottom is 3/32" on 5/32" centers it sits about 4" off the bottom to clear the dip tube. Kettles are 80qt Concord with a diameter of 18". Chugger pumps. I add additional water to compensate for the false bottom void. Last batch 20# of grain, 9.5 gallons mash water. Exactly 3 gallons sit under my false bottom. 1.85 qt to lbs ratio.

I've tried every throttle setting on the my chuggers. From full open to just a tick open and everything in between. I turn the pump off mix the grain bed. It floats perfectly. I turn the pump on in just a few minutes it's down on the false bottom. My efficiency is between 75-80% depending on the grain bill. I would think this only affects my sparge. Clarity of the wort is good.

Worried about nothing? What do ya'll think?

701pilot · Posted: Sun May 14, 2017 7:12 pm Post subject:

Sounds like everything is working as it should. It is normal for the grain bed to be on the bottom, especially using a recirculation mash. The grain bed forms a filter, filtering the wort clear. If you stop the pump, the grain bed will expand and look as if it is floating.

If your are experiencing a stuck sparge, (recirculation slowing to a drip) now that is a different story.

I get about 85% mash efficiency on average. I don't spend 90 minutes sparging, I'm only doing about 7 gallons to the boil kettle. It takes me about 45 minutes.

I'm using 60qt Tall Boy kettles with the same perforation false bottom as yours but only have 1qt sitting under mine. I also use Chugger pumps. I run the pump wide open starting about 15 minutes after mash in. Allowing the grain bed to settle on its own before pumping.

LarMoeCur · Joined: 14 Feb 2015 Posts: 18

Thanks 701Pilot, I've been hitting all my brewing number so I figured I was worried about nothing.

Joebrewing · Joined: 19 Jan 2014 Posts: 41

If you have a sight gauge you can tell if there is a vacuum because the water in the sight gauge will start to drop. I have had to throttle back the pumps a couple of times because of that. I seem to have resolved it by milling slightly coarser.

LarMoeCur · Joined: 14 Feb 2015 Posts: 18

Joebrewing · Joined: 19 Jan 2014 Posts: 41

If you are seeing that vacuum, try to mill a little bit wider, or if that isn't an option, add some rice hulls (maybe start with 4oz). I have also just stirred the bed and had that work to solve the issue. I would work to solve the vacuum issue so that you can run the pumps totally open. Throttling the pumps will change how quickly you can ramp the temperatures and may change the difference in temp between the MLT and the HLT.

**kal** · Posted: Tue May 16, 2017 4:01 pm Post subject:

+1 to what Joebrewing said. The goal is to not have to throttle the pumps at all.

Kal