Electric Brewing Supply 30A BCS Giveaway!


Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > "Sinkhole" when batch sparging
Reply
 
LinkBack Thread Tools
Old 04-15-2013, 04:39 PM   #1
Bdigs
Feedback Score: 2 reviews
Recipes 
 
Join Date: Apr 2011
Location: Chico, ca
Posts: 22
Default "Sinkhole" when batch sparging

Hey all, I'm having a problem when batch sparging, and hope to get a little advice from you batch sparge vets. Here's my setup:
Converted keg with 15 inch jaybird false bottom.
Standard ball valve/diptube pickup from dead center of screen.
I mash in, let sit for 20 minutes, stir.
20 minutes later, I start vourlof/recirc with pump very slow
When wort clears I've tried two methods: cranking the pump all the way (still recirculating) for 20 seconds, then transferring to BK. OR transferring to BK and running off at 1/2 throttle on pump. Both these methods give the same resulting problem, which is:
Big "sinkhole" forms about 4 inches in diameter where grainbed is a few inches below the rest. The wort channels to this spot, I can see it when wort level gets low enough. A little right and down from dead center (where the diptube would be).
After this first running, I add my second sparge water addition, stir, and repeat. I get the same dang hole in the same spot.
Has anyone had this happen? Jaybird sent me his level 1 screen, thinking that the FB might have been bowing and causing or contributing to the problem, but sadly, I used it yesterday and got the same result as before.
Finally, my efficiency isn't terrible considering it's channeling so badly. I'm getting between 67% and 74%, but I know I'm leaving sugars behind and want to get them!

grainbed-003.jpg  
__________________
Bdigs is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 04:59 PM   #2
golfduke
Feedback Score: 1 reviews
Recipes 
 
Join Date: Mar 2013
Posts: 115
Liked 29 Times on 16 Posts
Likes Given: 4

Default

could it be from your recirc line making direct contact with the same portion of the grain bed?? Interesting... and wierd. I've never had a channelling issue with my setup, which is very similar to yours (direct fired keggle with recirc, FB, and diptube).

I also sparge slow though. maybe about 1/4 turn of a ball valve. It takes me about 5-7 minutes to collect 2 gallons of runnings

__________________
golfduke is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 05:04 PM   #3
Bdigs
Feedback Score: 2 reviews
Recipes 
 
Join Date: Apr 2011
Location: Chico, ca
Posts: 22
Default

Now that you mention it, I do have my recirc line above the spot where the hole forms...... For this brew I had a 2 qt/lb water to grain ratio, so with 23 lbs of grain the mash was nearly to the top of the keg. I would wonder if slowly vourlof/recirculating (about a gallon/minute) would actually penetrate straight down to the bottom forming the hole. I wouldn't think so, but definitely a possibility. Thanks for the thoughts.

__________________
Bdigs is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 05:08 PM   #4
one-L
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2013
Posts: 308
Liked 85 Times on 67 Posts
Likes Given: 2

Default

I think channeling is generally only an efficiency issue when flysparging, as you are going to have liquid moving to that area, and not flowing through/dissolving sugars in other areas of the mash. If you're batch sparging and stirring before running off, you're dissolving the sugars into the liquid regardless.

__________________
one-L is offline
2
People Like This 
Reply With Quote Quick reply to this message
Old 04-15-2013, 05:08 PM   #5
bknifefight
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2009
Location: PA
Posts: 1,902
Liked 95 Times on 73 Posts
Likes Given: 41

Default

+1 to a slow drain of the sparge. It should help prevent any channeling like you are having here.

__________________
bknifefight is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 05:17 PM   #6
Yooper
Ale's What Cures You!
HBT_ADMIN.png
Feedback Score: 0 reviews
 
Yooper's Avatar
Recipes 
 
Join Date: Jun 2006
Location: Upper Michigan
Posts: 61,667
Liked 4635 Times on 3366 Posts
Likes Given: 909

Default

Quote:
Originally Posted by one-L View Post
I think channeling is generally only an efficiency issue when flysparging, as you are going to have liquid moving to that area, and not flowing through/dissolving sugars in other areas of the mash. If you're batch sparging and stirring before running off, you're dissolving the sugars into the liquid regardless.
Right. Channeling isn't a factor at all for batch sparging so I wouldn't worry about it.

I assume your technique is to mash in, stir like crazy, and then recirculate later? Then, to draw off your first runnings, add the sparge water and stir like crazy, then draw off the second runnings? I assumed so, but your post wasn't clear and I wanted to make sure I understood your process.
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006
Yooper is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 05:21 PM   #7
zachattack
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2012
Location: , MA
Posts: 2,503
Liked 242 Times on 208 Posts
Likes Given: 130

Default

Quote:
Originally Posted by one-L View Post
I think channeling is generally only an efficiency issue when flysparging
Exactly. When batch sparging you mix the hell out of everything before you drain, so channeling isn't a concern.
__________________
zachattack is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 05:30 PM   #8
Bdigs
Feedback Score: 2 reviews
Recipes 
 
Join Date: Apr 2011
Location: Chico, ca
Posts: 22
Default

Yooper, yes I do it just as you describe. I always thought that you want the grainbed to drain uniformly whether batch or fly sparging. I'll try running off slower and dispersing the wort return on my pump line, to see if that eliminates the hole. Do you all crank the pump all the way to "set the grainbed" and then back down to whatever flow you like? Or do you recirculate until clear and then just run off at your preferred speed?

__________________
Bdigs is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 06:11 PM   #9
golfduke
Feedback Score: 1 reviews
Recipes 
 
Join Date: Mar 2013
Posts: 115
Liked 29 Times on 16 Posts
Likes Given: 4

Default

I recirculate and sparge at the same flow-rate, regardless of gristload, water ratios, or temperature...

__________________
golfduke is offline
 
Reply With Quote Quick reply to this message
Old 04-15-2013, 06:16 PM   #10
Yooper
Ale's What Cures You!
HBT_ADMIN.png
Feedback Score: 0 reviews
 
Yooper's Avatar
Recipes 
 
Join Date: Jun 2006
Location: Upper Michigan
Posts: 61,667
Liked 4635 Times on 3366 Posts
Likes Given: 909

Default

Quote:
Originally Posted by Bdigs View Post
Yooper, yes I do it just as you describe. I always thought that you want the grainbed to drain uniformly whether batch or fly sparging. I'll try running off slower and dispersing the wort return on my pump line, to see if that eliminates the hole. Do you all crank the pump all the way to "set the grainbed" and then back down to whatever flow you like? Or do you recirculate until clear and then just run off at your preferred speed?
No, you don't need the grainbed to drain uniformly, and you don't want to drain slowly.

I'm simplifying the basics here, but when you batch sparge you're not getting sugars out of the grain from the process of diffusion, as you are in a fly (continous) sparge.

You stir in the "batch" of sparge water and stir like you mean it. Stir well and thoroughly, then immediately vorlauf and drain. You don't want the sugars to "settle" back on the grain- you want the sugars that were "knocked off" of the grain to be in the liquid and so you'll drain the liquid. The shape/size/consistency of the grainbed is immaterial and a slow drain may inhibit the sugars from being in solution rather than help your efficiency.

I know lots of batch spargers let the grain bed settle for 10 minutes, or drain slowly, and swear it works for them. I can't argue with success, but there is no scientific reason it would be better than a quick run off and no waiting period. Just the reverse would be more likely.
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006
Yooper is offline
 
Reply With Quote Quick reply to this message
Reply



Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Such a thing as "Black Friday" or "cyber Monday" for homebrew supply? StusBrew General Beer Discussion 37 11-29-2013 11:07 PM
Flavorful "Small" or "Session" beer. Less base malt? killsurfcity All Grain & Partial Mash Brewing 9 04-22-2012 01:25 PM
"American" or "Imperial" Oatmeal Stout Recipe: Critiques please! cladinshadows Recipes/Ingredients 4 01-04-2012 10:21 PM
Bucephalus "Martingale" - partial mash "fast" Festbier kwantam Recipes/Ingredients 3 03-23-2011 07:31 PM
First Batch - Is this "normal" or "contamination"? Red Clay Beginners Beer Brewing Forum 7 08-26-2007 02:11 PM