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General Category => Equipment and Software => Topic started by: richardt on January 14, 2011, 07:44:07 PM

Title: Batch Sparge Theory
Post by: richardt on January 14, 2011, 07:44:07 PM
I've read multiple posts on this forum as well as Denny's recent article about batch sparging. 

I get and agree with the whole "equal-concentration-of-sugars-throughout-the-mash" idea.

I have a hypothetical question regarding the lautering (or sparging) aspect of the process:

Assuming no change in temp, SG, wort composition, grist crush, etc., it seems that a larger drain surface area and/or shorter distance the wort must travel to get to the drain would be critical in terms of lautering (or sparging) speed.

What designs work best and why?  Has anyone ever tried a 3-D sparge manifold?  Why not?

I have a 10 gallon round Rubbermaid/Gott/Igloo cooler which can result in a grain bed of considerable vertical depth (e.g., up to the 8 gallon mark for high gravity beers using 25+ lbs of grain).  Lautering/sparging seems to take longer.  I suspect it has to do with grain bed compaction given its 12-18+ inch depth.

Hypothetically speaking, would a mildly domed 12-inch round SS false bottom with a 12-inch SS bazooka braid attached vertically help speed up batch sparging in a 10 gallon round cooler?
Title: Re: Batch Sparge Theory
Post by: denny on January 14, 2011, 07:53:47 PM
Sorry to not really answer your question, but being the pragmatic type I am, switching to a rectangular cooler seems a much simpler solution.  But hypothetically, I'd guess you're correct.  But that's a difficult solution compared to a new cooler!
Title: Re: Batch Sparge Theory
Post by: Hokerer on January 14, 2011, 08:08:47 PM
Hypothetically speaking, would a mildly domed 12-inch round SS false bottom with a 12-inch SS bazooka braid attached vertically help speed up batch sparging in a 10 gallon round cooler?

Theoretically, it would seem like that would speed things up.  Not sure about a 12-inch weenie sticking up into your mash, though - seems that could make stirring a bit of a problem
Title: Re: Batch Sparge Theory
Post by: richardt on January 14, 2011, 08:52:18 PM
Yeah, Denny, you're right.  That would be the far more practical thing to do.
I do have a big rectangular cooler, ... but it is red (... big sigh :-\). 

Hoeker--you're also right. A "12-inch weenie" would probably get fractured or bent while stirring a stiff mash.

I does give me a different idea, though: Instead of the stiff bazooka screen what if there was a flexible SS hose braid (like what Denny uses) with the end crimped and a long string attached to the end of it.  Let it be flaccid during the mash and then pull it taut vertically when it is time to "perform" the lauter/sparge?

Sorry for the double entendres--it did start off as a legimate academic question...
Title: Re: Batch Sparge Theory
Post by: blatz on January 14, 2011, 09:11:12 PM
*edit*

does the braid really get suction along the full length of the braid?

I don't think it does, which would make the length of the braid somewhat moot.

not sure entirely.
Title: Re: Batch Sparge Theory
Post by: denny on January 14, 2011, 09:12:08 PM
Look, I've gotta say that other than as a hypothetical exercise, this idea just isn't practical.  Why go to all that effort when you can just build a new cooler?
Title: Re: Batch Sparge Theory
Post by: denny on January 14, 2011, 09:14:13 PM
*edit*

does the braid really get suction along the full length of the braid?

I don't think it does, which would make the length of the braid somewhat moot.

not sure entirely.

I've experimented with this numerous times and the braid gets no "suction" at all.  That's why the length of braid doesn't really matter.  All the draining happens where the braid attaches to the outlet.  You can prove it by filling your (rectangular) cooler with water and lifting the braid out of the water as it drains.  No change in flow rate.
Title: Re: Batch Sparge Theory
Post by: blatz on January 14, 2011, 09:17:46 PM
*edit*

does the braid really get suction along the full length of the braid?

I don't think it does, which would make the length of the braid somewhat moot.

not sure entirely.

I've experimented with this numerous times and the braid gets no "suction" at all.  That's why the length of braid doesn't really matter.  All the draining happens where the braid attaches to the outlet.  You can prove it by filling your (rectangular) cooler with water and lifting the braid out of the water as it drains.  No change in flow rate.

that's what I was thinking - the braid acts as a filter, not a straw - the wort closest to the drain is being sucked out first - no different than if there were no braid at all.  I think a lot of people assume it is being sucked evenly along the braid like a manifold, which is not the case
Title: Re: Batch Sparge Theory
Post by: Pawtucket Patriot on January 14, 2011, 09:55:18 PM
Denny & blatz, that's exactly the reason I shortened the braid in cooler. And now I have the added benefit of not having an obstructive braid in the way when I'm stirring my mash!
Title: Re: Batch Sparge Theory
Post by: euge on January 14, 2011, 10:23:31 PM
*edit*

does the braid really get suction along the full length of the braid?

I don't think it does, which would make the length of the braid somewhat moot.

not sure entirely.

I've experimented with this numerous times and the braid gets no "suction" at all.  That's why the length of braid doesn't really matter.  All the draining happens where the braid attaches to the outlet.  You can prove it by filling your (rectangular) cooler with water and lifting the braid out of the water as it drains.  No change in flow rate.

Consider this- that while lifting the braid up doesn't alter flow rate because the max volume of fluid is exiting the drain restriction at any given moment until almost all the wort is gone.
Title: Re: Batch Sparge Theory
Post by: tschmidlin on January 14, 2011, 10:34:02 PM
Yes, as long as the maximum flow rate into the braid is faster than the flow rate out the end, raising the braid won't change it.  But if you reduce the available surface area too much with a tiny braid, a tiny mesh, or if it gets clogged, then it will alter the flow rate.  If clogging is a problem then having a longer braid will help because there will be more surface area for the wort to flow through.

But Denny has said in the past that he tested various lengths of braid and it makes no difference in his system, and based on the other thread he is crushing pretty fine, so I can't imagine you'd have any real issue.
Title: Re: Batch Sparge Theory
Post by: kerneldustjacket on January 14, 2011, 11:06:59 PM
I recently started doing no-sparge batches, and had to shift to my 150 quart cooler to be able to hold the entire grain bill plus all the water to make my pre-boil volume.
For a thirty pound grist, the grain bed depth was 4 inches. I ran off 15 gallons of wort in 15 minutes, and it ran very clear after vorlauf.

I have no frame of reference for what are normal run-off times when doing no-sparge and batch sparges.
Can anyone elaborate for me? Denny, surely you know by heart how long to expect a batch to run off based on volume going to the kettle.

My guess is that so long as its not a stuck mash, grain bed depth has no effect on run-off speed for batch sparging.

Based on my current knowledge, the OP would do well to set up his rectangular cooler as a mash tun. It can't hurt to have both available, and as posted by others, it's a simple and cheap thing to do.
Title: Re: Batch Sparge Theory
Post by: denny on January 14, 2011, 11:17:16 PM
Denny, surely you know by heart how long to expect a batch to run off based on volume going to the kettle.

The one time I really timed it, it took 15 min. form the time I started the mash runoff til I finished the sparge runoff.  That includes the mash vorlauf, stirring in the sparge water, and sparge vorlauf.  That was for 8 gal. of wort in the kettle.
Title: Re: Batch Sparge Theory
Post by: kerneldustjacket on January 14, 2011, 11:26:21 PM
Denny, surely you know by heart how long to expect a batch to run off based on volume going to the kettle.

The one time I really timed it, it took 15 min. form the time I started the mash runoff til I finished the sparge runoff.  That includes the mash vorlauf, stirring in the sparge water, and sparge vorlauf.  That was for 8 gal. of wort in the kettle.

Mine was timed after vorlauf...and was non-stop with a fully-open 1/2" full port ball valve. Assuming that your pause to re-fill, stir, and vorlauf took half the 15 minutes, and that your volume was roughly half mine, the rates of actual wort drain-off were very similar; around 1 gallon a minute.
Title: Re: Batch Sparge Theory
Post by: richardt on January 14, 2011, 11:31:00 PM
Hmmm...  I'm listening to everyone's comments.  
And, yes, being a practical person, I probably will switch to a rectangular cooler.
My intuition still tells me that grain bed depth does make a difference.  
Title: Re: Batch Sparge Theory
Post by: denny on January 14, 2011, 11:40:38 PM
A difference in what? Runoff speed?  Mine is consistent whether the cooler is 1/4 full or completely full.
Title: Re: Batch Sparge Theory
Post by: euge on January 14, 2011, 11:51:33 PM
Seems to me that when it gets thicker in the sense that lower grain to water ratio efficiency suffers. Which is what happens when brewers have maxed the tun capacity out.

In that case I'd rather do a third sparge. 
Title: Re: Batch Sparge Theory
Post by: richardt on January 15, 2011, 01:19:43 AM
All these comments are very interesting and thought-provoking.  Depending on the sources, it seems that, for the homebrewer, the ideal grain bed depth is between 4-12 inches.  Perhaps counterintuitively, a deeper grain bed is more "efficient" (up to a point), but not necessarily "faster."  See JP's HTB Appendices E and F for more details, if interested.

A grain bed depth beyond 12 inches might have compaction issues in a 10 gallon round Igloo cooler (internal dimensions 12 inches diameter x 18 inches deep) given that the height would then exceed the width of the grain bed.  That situation (i.e., grain bed height exceeding its width) does not occur in a rectangular mash-lauter tun regardless of lauter design (e.g., false bottom, pipe manifold, or screen) or grist amount (e.g., high versus normal gravity recipe).

My personal observations with the high gravity brewdays seems to suggest slower lautering.  But, there are too many other potential variables (different recipes, different wort temps, mill gap settings, coarse vs fine grist, use of wheat, etc.) involved in order for me to really be able to say for sure.  So I certainly respect the views of those with far more experience.  Nonetheless, being a practical person, I think the hypothetical 3-D MLT design isn't.
Title: Re: Batch Sparge Theory
Post by: kerneldustjacket on January 15, 2011, 02:17:53 AM
My personal observations with the high gravity brewdays seems to suggest slower lautering.  But, there are too many other potential variables (different recipes, different wort temps, mill gap settings, coarse vs fine grist, use of wheat, etc.) involved in order for me to really be able to say for sure.  So I certainly respect the views of those with far more experience.  Nonetheless, being a practical person, I think the hypothetical 3-D MLT design isn't.

{emphasis added by me. jw}

Someone else please chime in and agree or disagree...but I see two routes regarding high gravity brew days:
1. Conduct a parti-gyle, and get a high gravity first runnings beer and a mid to low gravity second-runnings beer.
2. Do one beer but fly sparge.

The issue, so far as I see it, lies in how much water is retained by the grains. This was suggested to me by Kai's chart that shows lower efficiency's as the target gravity goes up. (link below; about half way down)
http://braukaiser.com/wiki/index.php/Batch_Sparging_Analysis#True_v.s_apparent_grain_absorption (http://braukaiser.com/wiki/index.php/Batch_Sparging_Analysis#True_v.s_apparent_grain_absorption)
Title: Re: Batch Sparge Theory
Post by: denny on January 15, 2011, 02:21:44 AM
Why couldn't you do one beer batch sparged?  I've done that many times.
Title: Re: Batch Sparge Theory
Post by: kerneldustjacket on January 15, 2011, 05:05:46 AM
Why couldn't you do one beer batch sparged?  I've done that many times.
Yes, I'm sure you can Denny. I only recently converted from fly to batch sparging (partly you're fault, Denny!  ;)) so forgive my ignorance of what's possible.  Also I suppose that I'm thinking in terms of getting as much sugar as you can from a high gravity batch; either in one beer or as a parti-gyle, while also avoiding an overly long boil.

Do you get reasonable efficiency as your gravity increases?
Again, I'm flying off of Kai's chart here, and maybe looking at OGs that are above 1.095; but if you say you've done it then I have no hesitation about believing you.


Duh! I just realized I could make a direct link to Kai's chart:
Quote
http://braukaiser.com/wiki/index.php/File:Lauter_efficiency_and_wort_strength.gif
Title: Re: Batch Sparge Theory
Post by: denny on January 15, 2011, 05:27:08 AM
My efficiency stays around 85% up to maybe 1.085 OG.  After that I either do a partigyle or sparge more (and of course boil longer) to keep efficiency up on bigger beers.  Pretty much like you'd do with fly sparging.
Title: Re: Batch Sparge Theory
Post by: kerneldustjacket on January 15, 2011, 01:28:33 PM
My efficiency stays around 85% up to maybe 1.085 OG.  After that I either do a partigyle or sparge more (and of course boil longer) to keep efficiency up on bigger beers.  Pretty much like you'd do with fly sparging.

Yes...that's what I was proposing...tho I didn't say it as concisely as you did ;D.
But I didn't define how high of a high gravity...so that's my fault.

Makes me wonder if we need to add a few terms to describe gravity:
(older folks will recognize the similarity to "HF" "VHF" & "UHF" from old radios and TVs)
HG: High Gravity...up to 1.085?
VHG: Very High Gravity...1.086 to 1.100?
UHG: Ultra High Gravity...1.101+


Also, I have to confess that the highest gravity I've ever brewed to was 1.084. :-\
Title: Re: Batch Sparge Theory
Post by: bonjour on January 15, 2011, 02:27:57 PM
UHG: Ultra High Gravity...1.101+
Ahhhh,
stepping just out of the world of session beers ;)
Title: Re: Batch Sparge Theory
Post by: kerneldustjacket on January 15, 2011, 03:30:59 PM
UHG: Ultra High Gravity...1.101+
Ahhhh,
stepping just out of the world of session beers ;)

Fred, feel free to shift the category numbers upward...

When it comes to OG, I'm the Yin to your Yang.  :D
Title: Re: Batch Sparge Theory
Post by: a10t2 on January 15, 2011, 05:15:07 PM
Nonetheless, being a practical person, I think the hypothetical 3-D MLT design isn't.

I definitely think it would work. I'm less convinced that there would be a benefit over more conventional designs.

If lautering speed is the concern, I think all the same concerns that apply to fly sparging would also apply to batch sparging. The absolute best design is probably a false bottom, since you would effectively be able to drain the entire area of the mash simultaneously. And you'd want the shallowest grain bed possible.

As a practical consideration, I have a lautering system that's optimized for fly sparging. (A slotted CPVC manifold. (http://seanterrill.com/wp-content/uploads/2009/04/img_1943-384x288.jpg)) Using a March pump, I average about eight minutes from starting the runoff to filling the kettle. That probably means each ~3.5 gal runoff takes about two minutes. I don't see any reason to experiment with other designs.
Title: Re: Batch Sparge Theory
Post by: a10t2 on January 15, 2011, 05:17:15 PM
Makes me wonder if we need to add a few terms to describe gravity:

How about HG: 20-30°P; VHG: 30-40°P; UHG: >40°P?
Title: Re: Batch Sparge Theory
Post by: richardt on January 15, 2011, 06:52:04 PM
If lautering speed is the concern, ...[t]he absolute best design is probably a false bottom, since you would effectively be able to drain the entire area of the mash simultaneously. And you'd want the shallowest grain bed possible.
I agree.  I think the 10 gallon round Igloo cooler is experiencing mash bed compaction on the high gravity brews despite the use of a 12 inch x 1 inch SS Bazooka screen in the horizontal position.  That's why I wanted to look for ways to shorten the "wort travel" distance and increase lauter surface area by considering a 3-D lauter design (even though it might not be very practical to implement and use).
Quote
As a practical consideration, I have a lautering system that's optimized for fly sparging. (A slotted CPVC manifold. (http://seanterrill.com/wp-content/uploads/2009/04/img_1943-384x288.jpg)) Using a March pump, I average about eight minutes from starting the runoff to filling the kettle. That probably means each ~3.5 gal runoff takes about two minutes. I don't see any reason to experiment with other designs.
Is the suction from the March pump helping you drain the wort faster?  I am just using gravity and time.  My spigot is 3/8" (5/16"ID), but I am convinced the "bottleneck" during lautering is the grainbed compaction around the surace of the Bazooka screen.  I have to scrape the screen with my mash spoon much like one has to scrape the fine nylon mesh screen on the funnels when transferring wort into the fermenter.  That's what intriques me about Denny's comments regarding the rather short length of his SS braid in his mash tun.  This tells me that there's no grain bed compaction occurring in his system.  His example (using water, i.e., a universal solvent) doesn't quite prove the point to me as it does not reflect the fact that we're actualy straining wort (a viscous colloidal solution) from the mash (a thick "suspension") -- a process which can be quite sensitive to grain bed compaction.
I am looking at two possible practical solutions to the problem of lautering high gravity brews:
1.) Use a rectangular cooler (to decrease grain bed height)
2.) Use a false bottom or CPVC pipe manifold (to increase lauter surface area) on the Igloo.
Title: Re: Batch Sparge Theory
Post by: euge on January 15, 2011, 09:19:48 PM
It may be as simple as slowing it down to eliminate your compaction issues. I always went full blast no matter the grist ratio and ran into problems- especially with stiff heavy mashes. Throttle back... no compaction issues. It is what it is. Headache gone.

Title: Re: Batch Sparge Theory
Post by: richardt on January 16, 2011, 12:04:18 AM
You're probably right Euge.  I will throttle back next time--at least for high gravity brews on my 10 gallon round cooler.
Title: Re: Batch Sparge Theory
Post by: majorvices on January 16, 2011, 03:30:43 PM
This probably answers no questions, but I thought I'd mention I batch sparge in a blickmann kettle with a blickmann false bottom. Before that I was using a bazooka braid in said kettle. I saw no difference in efficiency after the switch.
Title: Re: Batch Sparge Theory
Post by: denny on January 16, 2011, 04:17:31 PM
It may be as simple as slowing it down to eliminate your compaction issues. I always went full blast no matter the grist ratio and ran into problems- especially with stiff heavy mashes. Throttle back... no compaction issues. It is what it is. Headache gone.



Usually if you start off slow you can speed things up after the grain bed is established.
Title: Re: Batch Sparge Theory
Post by: maxieboy on January 16, 2011, 05:23:29 PM
Usually if you start off slow you can speed things up after the grain bed is established.

This has been my experience as well.
Title: Re: Batch Sparge Theory
Post by: euge on January 16, 2011, 08:01:55 PM
It may be as simple as slowing it down to eliminate your compaction issues. I always went full blast no matter the grist ratio and ran into problems- especially with stiff heavy mashes. Throttle back... no compaction issues. It is what it is. Headache gone.



Usually if you start off slow you can speed things up after the grain bed is established.

Usually if you start off slow you can speed things up after the grain bed is established.

This has been my experience as well.

Just to clarify and prevent confusion... I only opened it up full-bore after performing a vorlauf and setting the bed. Still got a stuck mash nearly every time. It was a real PITA so I adapted after struggling through many batches. :-\

Title: Re: Batch Sparge Theory
Post by: yeastmaster on January 19, 2011, 02:56:32 AM
I always seem to 65-70% efficiencies with my sparge.  I mash/sparge in a 10 gallon round cooler with a bazooka screen and these days typically batch sparge, when I fly sparge my efficiencies might get up to 75%.  I tightened up my mill to get a better crush which helped some but it always seems low to me compared to some of the numbers I see people posting.  Do people find a big difference between rectangular vs round coolers as mash/lautertuns?  I frequently don't do a mash out, maybe doing that would help a little too.
Title: Re: Batch Sparge Theory
Post by: Kaiser on January 24, 2011, 07:45:07 PM

What designs work best and why?  Has anyone ever tried a 3-D sparge manifold?  Why not?

This sounds very much like the design of a Strainmaster, a lauter device where the sweet wort is lautered through a set of perforated pipes that are located throughout the grain bed. Here is a diagram that I found in Narziss/Back's book:

(http://www.braukaiser.com/images/misc_forum/Strainmaster.gif)

This type of lautering device has not been widely used, though.

Kai
Title: Re: Batch Sparge Theory
Post by: denny on January 24, 2011, 07:52:51 PM
This type of lautering device has not been widely used, though.

Kai

I guess people just don't want to strain themselves!   ;D
Title: Re: Batch Sparge Theory
Post by: richardt on January 24, 2011, 10:16:26 PM
Good one, Denny. ;)

Kai, thanks for the pic.  It looks like a real pain to make and clean!

 I was perusing my old beer mags this weekend and saw a 3-D MLT design in the BYO issue (OTTOMH, I think it was the July/August 2008 BYO issue, or there abouts).  The pics are in the article on "Turbid Mashing".  It seems that they've incorporated the 3-D lautering manifold into the mash stirrers. 

Regardless, I'm not sure it would be easily implemented on a homebrew level.
Title: Re: Batch Sparge Theory
Post by: sharg54 on February 04, 2011, 08:21:26 AM
I actually ran into Dennys site by total accident when looking for Batch Sparge info and gave it a try. I have a rectangular Got 48 Qt cooler with a very nice manifold all set up the way John Palmers site tells you to for a fly sparge and it worked fine. No stuck runoff grate effency  and no increased grain bill as was suggested may be required and no change of equipment. I just made a Bock , Imperial Stout and a porter last week doing it that way and the only thing I can see is it is best to start out slow and let your grain bed settle than just kick the valve open and let it rock. I did notice that running at such a high rate on the drain caused things to channel rather than drop down like it did on a fly sparge but being as your pulling everything out at once it didn't really matter. Added the rest of my 3.5 gallons for a 7 gallon boil and the OG was almost identical on all three batches. Not more than a .007 split. Hats off Denny.... ;D