Unusual (to me) hole in my grain bed

[stevenboise]

I've attached two photos of my grain bed from this past weekend. One is before we drained the water after sparging (hence the clearness of the water) and the other after the water was drained.

I'm curious if there are any thoughts on what created this "hole" or "gap" along the side of the mash tun. It seemed like it was just in this one spot. The rest of the wall around the grain bed seemed fine. How does one prevent this from happening? I don't recall ever seeing this on my grain bed in the past.

 

[jdauria]

Is it possible that when recirculating to set the grain bed, that you dumped wort back into the mash tun too hard in one area?

 

[stevenboise]

Thanks for the reply. I use "The Ultimate Sparge Arm" (their name, not mine) from More Beer to recirculate and then I fly sparge. I know, I could use the "Arm" for both, but I've had the fly for a long time and like it. Personal preference, that's all. The "Arm" recirculates right in the middle of my grain bed and I do so slowly right above the grain bed to avoid the water spilling over and creating a channel in the middle. The weird thing is this happened on the edge.

 

[dlester]

grains will rise and settle in weird ways. If you are using a sparge arm, it will create movement of grains. What you are seeing is the result of moving grain. I wouldn't be that concerned, I've seen it multiple times. As long as your water remains above the grains, your fine.


Good luck, and by the way it looks good.

 

[stevenboise]

Okay, thanks for the reply. Now that I'm doing more and more all grain I'm seeing stuff that I've never seen before.

 

[korisu]

Are you using a cylindrical cooler for your mashtun? And did you take these pictures after the tun had a chance to cool down several dozen degrees? If so, it's possible that the plastic on the inside of the cooler walls expanded during the mash, causing it to buckle around one place in the edge. This happens with my HLT sometimes, and it looks like it happened here due to the particular shape of the hole. It's not a problem if it happens at mash temps, because during the sparge, it will likely stay at the same temp and so the buckled area will hold its shape. That will keep a tight enough seal for your sparge, so you won't get channeling down that side. Overall, if your OGs seem close enough to your recipe, you shouldn't have to worry about this little issue.


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[korisu]

Also, if you feel like you are getting edge channeling during your sparge, go ahead and stir up the top layer of the grain during the sparge itself. You won't get grain runoff in your boil kettle, because of the layers of grain beneath it. Stirring up the top layer will give you an even seal around the edges. I do this when I notice that my grain cake pulls in slightly from the edges over the course of the sparge. I also recommend draining through a hop bag into the kettle after vorlaufing, just to catch any rogue chunks that still make it through.


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