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Jun 08, 2022 View:

Agitation in fermenters

We make our rye whiskeys with 100% rye and have issues moving the mash once the grain settles out during fermentation.  We changed the mash bill to less rye and tried using a liquifier but found it wasn't worth the money.

We are looking to put in some kind of slow agitator to keep the solids suspended without adding a lot of oxygen in to the mash as it ferments.  Any suggestions or ideas?


Thank you very much!


Have you considered putting in a false bottom?

have you considered/attempted agitating it at the end of fermentation before the mash is transferred?

Depending on your fermenter density, 'slow' agitation may not help with suspended solids if it's too thick.


Are you just having problems pumping the fermented mash to the still after fermentation?  If so, what type of pump are you using?  We run very heavy mashes (1400 lbs of grain in 550 gallon fermenters and we had problems at first when we were using an electric centrifugal pump.  We switched to Air Operated Diaphragm pumps and they move the mash with no problem.  If you have an air compressor you might want to look at that as a transfer solution.


Had the same issue now we just blast the bottom with some compressed air before transferring out of fermentors. 

Reply:On 10/26/2016 at 2:47 PM, sonnyk said:

We are putting bridge-mounted agitators on the tops of our 550g Custom Metalcraft fermenters for a similar exact reason.  Still is half the size of the fermenter, so we run two batches per.  The issue is that batch one is grain heavy, and getting the fermenter homogeneous is impossible with a paddle.  I imagine it would help significantly during cooldown as well.

Nothing too fancy, 3/4hp motors with inline gear reductions.  Will machine a coupling and just use a long shaft down to the bottom with a simplistic impeller.  It doesn't need much.

It doesn't need to run for the length of the ferment, just start it before the pump over.



We use a Warren Rupp Sandpiper Model SB1 1/2.-A .  I don't think they make our model anymore but they are selling a HDB1 1/2 model which is very similar.  the air requirements are 90 CFM max at 20 - 40 PSI.  We have a very big Ingersoll Rand double air compressor unit but you should be able to get by with something much smaller.


I was going to say to make a air wand and blast it with some air before you start pumping. It really works great.


I use a 2" diaphragm pump plumbed in a loop on the tank. Run the pump for 3 min to mix the water and grain back into slurry, then flip a valve to transfer :-)