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General Category => All Grain Brewing => Topic started by: monk on April 19, 2010, 10:49:14 PM

Title: The Ideal Batch Sparge
Post by: monk on April 19, 2010, 10:49:14 PM
Hi Guys,

I've read that in order to perform an ideal batch sparge, one should collect his pre-boil volume of wort from two (fairly) equal run-offs.  Since I have a 5-gallon MT, I run into the problem of not having enough room in the tun to get enough volume from the first run-off.  For example, if I mash in 12# of grain with 3.5 gallons of water, I only have enough room for about a half gallon top-up at the end of the mash.  So my run off is about 2.5 gallons.  That means my batch sparge needs to be 4.5 gallons to acheive a 7 gallon pre-boil volume. 

So...how important is the "2 equal run-offs" rule?  Should I just drain the mash and do two equal sparges?  Is there some other way (that doesn't involve me buying a bigger mash tun)?

Thanks in advance!
Title: Re: The Ideal Batch Sparge
Post by: Hokerer on April 20, 2010, 12:31:40 AM
The "equal runoff" may be the "ideal" but even if they're unequal, it's not going to make all that huge a difference.  You might get slightly lower efficiency but, as long as you're consistent, you can account for whatever efficiency you regularly achieve.

That said, if 3.5 gallons is all you can get in your cooler with 12 pounds of grain, that comes out to 1.167 quarts/pound.  That puts you at the lower end of the range (thicker mash) of the normal 1 - 2 quarts/pound.  Since at least 1.25 and probably, even better, 1.5 quarts/pound is an "ideal" ratio, you might seriously consider a new cooler.  Get a cheap rectangular 36 to 48 quart (or even maybe larger) cooler and use Denny's "braid system" and you can have a brand new mashtun for very little money.
Title: Re: The Ideal Batch Sparge
Post by: tom on April 20, 2010, 01:51:52 AM
Check this out:  http://braukaiser.com/wiki/index.php/Batch_Sparging_Analysis#Effect_of_the_relative_run-off_sizes
Looks to me like 30% to 70% is only 1% less efficient than 50%.
RDWHAHB
Title: Re: The Ideal Batch Sparge
Post by: a10t2 on April 20, 2010, 03:14:43 AM
You could always do three equal runoffs and (at least in theory) get a small increase in efficiency.
Title: Re: The Ideal Batch Sparge
Post by: denny on April 20, 2010, 05:26:36 PM
My experience echoes everyone else's.  2 equal runoffs _may_ have a very slight advantage in efficiency, but it's not a big deal.
Title: Re: The Ideal Batch Sparge
Post by: MDixon on April 20, 2010, 08:15:19 PM
My experience echoes everyone else's.  2 equal runoffs _may_ have a very slight advantage in efficiency, but it's not a big deal.

2 equal runoffs (1 drain, sparge, drain again) is how most everyone performs a batch sparge. 3 runoffs (drainings of the tun) is what could potentially incur a slight boost in efficiency.  ;D
Title: Re: The Ideal Batch Sparge
Post by: denny on April 20, 2010, 09:52:01 PM
My experience echoes everyone else's.  2 equal runoffs _may_ have a very slight advantage in efficiency, but it's not a big deal.

2 equal runoffs (1 drain, sparge, drain again) is how most everyone performs a batch sparge. 3 runoffs (drainings of the tun) is what could potentially incur a slight boost in efficiency.  ;D

I guess I should have emphasized the "equal" runoffs part.  So, to clarify (or confuse things further), 2 equal runoffs may give you a _bit_ better efficiency than 2 close-to-equal (like within a gal.) runoffs.  Doing a 2nd batch sparge (3 runoffs in total ) _may_ give you a _bit_ better efficiency  than 2 runoffs.  For me, it becomes a point of diminishing returns thing.  If I my 2 runoffs are within a gal. of each other, there's not enough difference for me to worry about equalizing them.  And unless I'm using so much grain that I can't fit all the sparge water in the tun at once, there isn't enough gain in doing a second sparge addition for me to mess with it.
Title: Re: The Ideal Batch Sparge
Post by: monk on April 21, 2010, 09:10:05 PM
Thanks for all the replies, guys!  I'll do a little experiment with the next 2 batches, trying each of the methods.  I'm really not concerned with super good efficiency (grain isn't that expensive), but rather a smooth brewing experience that is fun.

I will return with data!
Title: Re: The Ideal Batch Sparge
Post by: bobby_m on June 05, 2010, 10:04:17 PM
The equal runoff theory also works when considering more than one sparge. Three equal runoffs of 2.25 gallons each is slightly more efficient than three completely different volumes. Denny is right, these are diminishing returns and just add more time to brew day. Things like crush and minimizing dead space are much more important.
Title: Re: The Ideal Batch Sparge
Post by: makemehoppy on June 07, 2010, 04:11:22 PM
 For example, if I mash in 12# of grain with 3.5 gallons of water, I only have enough room for about a half gallon top-up at the end of the mash.  So my run off is about 2.5 gallons.  That means my batch sparge needs to be 4.5 gallons to acheive a 7 gallon pre-boil volume. 
....
Aren't you forced to do 3 run offs?  If you only have space for 4 gallons and run off 2.5 that means the next sparge you can only fit and run off another 2.5 gallons.  If you are looking to collect 7 gallons based on above id to this:
Mash with 3.5 gallons and run off what I expect would be 2 gallons. Then do two batch sparges adding 2.5 gallons each time. The extra vourlaf and drain is extra work, but would will not lose time in your brew day if you start heating the other run offs while doing the sparges.
Title: Re: The Ideal Batch Sparge
Post by: The Rabid Brewer on June 08, 2010, 04:10:04 PM
2 equal runoffs (1 drain, sparge, drain again) is how most everyone performs a batch sparge.

I thought the common method, and the one I use, is to mash in at your preferred grain to grist ratio, nominally 1.3 qts per pound.  After draining, you do two equal size sparges (letting each rest ~15 minutes while stirring occasionally) to collect the rest of your wort. This is also the method that Kai describes in his article showing increased efficiency from equal size sparges.

Brian
Title: Re: The Ideal Batch Sparge
Post by: makemehoppy on June 08, 2010, 04:29:04 PM
I have never waiting 15 minutes between sparges after stiring. Are you expecting more conversion to occur? I just stir, vourlat and drain and repeat.
Title: Re: The Ideal Batch Sparge
Post by: bonjour on June 08, 2010, 04:40:27 PM
Me,  when I am not brewing a monster I usually batch sparge.  I'm worried about how much water to add because my first step is to drain the mash tun into my kettle.  Then I measure (dip stick, actually my mash paddle, calibrated) to see what I have then I add half the remaining, drain, then add what I need to hit my preboil volume.  Don't care if it's precise,  it's close enough.

Fred
Title: Re: The Ideal Batch Sparge
Post by: Hokerer on June 08, 2010, 04:43:45 PM
2 equal runoffs (1 drain, sparge, drain again) is how most everyone performs a batch sparge.

I thought the common method, and the one I use, is to mash in at your preferred grain to grist ratio, nominally 1.3 qts per pound.  After draining, you do two equal size sparges (letting each rest ~15 minutes while stirring occasionally) to collect the rest of your wort.

I've always understood the standard batch sparge to be what MDixon describes.  Dough in, mash (wait), optionally add mashout water, vorlauf, drain, add water, vorlauf, drain, done.
Title: Re: The Ideal Batch Sparge
Post by: richardt on June 08, 2010, 04:52:02 PM
I have never waiting 15 minutes between sparges after stiring. Are you expecting more conversion to occur? I just stir, vourlat and drain and repeat.

Although some conversion could occur if temps are maintained during that time, I think the rationale for waiting a period of time after stirring is to allow sugar diffusion from the husks and for the husks to settle towards the bottom (and create an effective filter bed) before lautering is begun.  I don't wait 15 minutes either.  I do wait about 5 and then open the valve a little bit, vorlauf, and then gradually open it up a little more to avoid grainbed compaction (10 gallon batches with an Igloo cooler).
Title: Re: The Ideal Batch Sparge
Post by: Kaiser on June 08, 2010, 08:18:25 PM
This is also the method that Kai describes in his article showing increased efficiency from equal size sparges.

In this article I'm talking about run-offs. The first comes from the mash and the 2nd comes from the 1st and possibly only sparge.

Kai
Title: Re: The Ideal Batch Sparge
Post by: dean on June 08, 2010, 08:34:59 PM
Kai, what if you added your first sparge say 10 minutes before taking any runnings, would it have the same effect as a single batch no-sparge with a severe hit in efficiency?
Title: Re: The Ideal Batch Sparge
Post by: denny on June 08, 2010, 09:35:13 PM
2 equal runoffs (1 drain, sparge, drain again) is how most everyone performs a batch sparge.

I thought the common method, and the one I use, is to mash in at your preferred grain to grist ratio, nominally 1.3 qts per pound.  After draining, you do two equal size sparges (letting each rest ~15 minutes while stirring occasionally) to collect the rest of your wort. This is also the method that Kai describes in his article showing increased efficiency from equal size sparges.

Brian

I almost never do more than a single sparge.  I get so little gain in efficiency form doing more that it isn't worth my time or effort.
Title: Re: The Ideal Batch Sparge
Post by: denny on June 08, 2010, 09:35:55 PM
I have never waiting 15 minutes between sparges after stiring. Are you expecting more conversion to occur? I just stir, vourlat and drain and repeat.

There's nothing to be gained from waiting.  I do what you do.
Title: Re: The Ideal Batch Sparge
Post by: denny on June 08, 2010, 09:37:31 PM
Kai, what if you added your first sparge say 10 minutes before taking any runnings, would it have the same effect as a single batch no-sparge with a severe hit in efficiency?

I'm not Kai, but yes...
Title: Re: The Ideal Batch Sparge
Post by: The Rabid Brewer on June 09, 2010, 06:28:56 PM
I think the rationale for waiting a period of time after stirring is to allow sugar diffusion...

That was my understanding as well (I think I read it in Palmer) but I haven't done a lot of experimentation.

Brian
Title: Re: The Ideal Batch Sparge
Post by: denny on June 09, 2010, 06:58:15 PM
I think the rationale for waiting a period of time after stirring is to allow sugar diffusion...

That was my understanding as well (I think I read it in Palmer) but I haven't done a lot of experimentation.

Brian

I've done a lot of experimentation on it.  No difference.
Title: Re: The Ideal Batch Sparge
Post by: bonjour on June 09, 2010, 08:45:10 PM
I think the rationale for waiting a period of time after stirring is to allow sugar diffusion...

That was my understanding as well (I think I read it in Palmer) but I haven't done a lot of experimentation.

Brian

I've done a lot of experimentation on it.  No difference.
That is the logic, but the proof is in the brewing.

Fred
Title: Re: The Ideal Batch Sparge
Post by: Kaiser on June 09, 2010, 09:06:11 PM
I think the rationale for waiting a period of time after stirring is to allow sugar diffusion...

That was my understanding as well (I think I read it in Palmer) but I haven't done a lot of experimentation.

I think the effects of that diffusion are commonly overstated. Throughout the mash the sugars dissolve into the wort which can be measured by the mash gravity test. Once you are close to 100% conversion efficiency there can't be a significant amount of sugars in the grains or husks or otherwise the mash gravity would be much lower than expected.

When you sparge there will be some diffusion but their contribution to the overall efficiency is really small due to the small amount of wort that is actually held inside the grit particles. The majority of the wort is on the outside and lautering washes that into the BK. Technical brewing texts do mention that the actual diffusion takes some time and allowing it to happen is a reason for slow lautering. However, those books are targeted at (large) commercial brewers which do worry about efficiency changes as small as 0.5% and less. We home brewers can't even measure that accurate.

If you have low lauter efficiency due to sparging too fast (and that only applies to fly sparging) it is because of the formation of channels and not insufficient time for sugar diffusion out of the grain.

Kai
Title: Re: The Ideal Batch Sparge
Post by: nyakavt on June 10, 2010, 05:18:49 PM
I know this is a bit late, but I thought about running sizes and batch sparging a bit and came up with an analogy that makes sense to me.  Imagine that you have a kettle that always leaves 1 gallon behind when drained.  So if you have 200 'points' of sugar and dilute it to make 5 gallons of wort, that's a 1.040 wort.  If the kettle is drained as much as possible, 1 gallon of 1.040 wort will be left behind, or 40 points out of a possible 200 (20%).  This is analagous to a no-sparge. 

Next collect the same amount of wort in two steps, first by collecting 3 gallons then collecting 1.  For the first runnings the wort will be 1.050 gravity, leaving 1 gallon behind.  Adding 1 more gallon of water will dilute the wort to 1.025, again leaving 1 gallon behind when drained.  So here you leave behind 25 points out of a possible 200, or 12.5%.  This is a single sparge with unequal runnings.

Finally, collect the same amount of wort in two equal steps.  This is done by a 3 gallon wort which is drained, followed by adding 2 gallons and again drained.  The first draining leaves 67 points behind, which is diluted to 1.022 by the second addition, and again leaving 1 gallon behind.  Here you leave behind 22 points, or 11%.  This is a single sparge with equal runnings.   

You can see the difference between equal and unequal runnings (1.5%) is relatively small even for a large difference in runoff sizes.  The size of the 'dead space' at the bottom of the kettle can be represented in your MT by the amount of wort absorbed by the grain and any dead space, easily measured on your next batch.
Title: Re: The Ideal Batch Sparge
Post by: Kaiser on June 10, 2010, 05:45:58 PM
I know this is a bit late, but I thought about running sizes and batch sparging a bit and came up with an analogy that makes sense to me.  Imagine that you have a kettle that always leaves 1 gallon behind when drained. 

That's exactly how I have modeled batch sparging on various occasions.

Kai
Title: Re: The Ideal Batch Sparge
Post by: nyakavt on June 10, 2010, 06:09:33 PM
I know this is a bit late, but I thought about running sizes and batch sparging a bit and came up with an analogy that makes sense to me.  Imagine that you have a kettle that always leaves 1 gallon behind when drained.  

That's exactly how I have modeled batch sparging on various occasions.

Kai

Yep, I've found your model to very accurately predict the into-kettle efficiency when all the starch is converted prior to the first runoff.  Since I got my refractometer inconsistencies sorted, my 3 most recent calculated efficiencies were within 1% of observed efficiency.  It's a very useful tool for recipe formulation and for seeing how much efficiency decline to expect when brewing bigger batches but collecting the same amount of wort.
Title: Re: The Ideal Batch Sparge
Post by: wilypig on June 14, 2010, 04:18:13 PM
I think the reason to wait is not for added conversion but to ensure the proper contact time with the mash to ensure full solubility of the remaining sugars. This will also aid in efficiency
Title: Re: The Ideal Batch Sparge
Post by: denny on June 14, 2010, 05:00:41 PM
I think the reason to wait is not for added conversion but to ensure the proper contact time with the mash to ensure full solubility of the remaining sugars. This will also aid in efficiency

Again, I've tried a lot of different methods and I've seen no difference.
Title: Re: The Ideal Batch Sparge
Post by: Kaiser on June 14, 2010, 05:44:46 PM
Yep, I've found your model to very accurately predict the into-kettle efficiency when all the starch is converted prior to the first runoff.  Since I got my refractometer inconsistencies sorted, my 3 most recent calculated efficiencies were within 1% of observed efficiency.  It's a very useful tool for recipe formulation and for seeing how much efficiency decline to expect when brewing bigger batches but collecting the same amount of wort.

Thanks. It's always good to have some back-up from the observations that other brewers make.

Kai