Lazy Man Sparge

[beretta]

During my last 2-3 batches I've gotten pretty lazy during my sparges. After about fifteen minutes of a regular english style sparge (after the grain bed settles), I simply opened the valve on my HTL, and emptied 3-4 gallons of sparge water into my MT. I ended up with about 7-8 inches of sparge water above the grain bed. It worked fine. Wort tasted correct, and my efficiency was around 85-89% (my usual). These beers aren't out of my pipeline yet, but soon I'll be tasting. It sure was easier than batch sparging or english sparging, but I'm wondering about the negatives. I thought the extra weight of the water might stick the mash, but it actually seems to make lauddering faster...Any thoughts?

 

[Walker]

I don't know what "english style" sparge means. Is that the constant trickling of water into the top of the MT as you drain out of the bottom? (usually called "fly sparging".)

If so... I'm not really seeing how this is easier than batch sparging since it sounds like you did one thing for a little while and then finished it like a batch sparge by just unloading a bunch of water in the tun at once.

 

[beretta]

err... yes, english sparge = fly sparging.

I guess the advantages are: 1) You don't disturb the grain bad, so no reason to recirculate the wort more than once. 2) The laudder doesn't require contant attention like normal fly sparging. 3) Contrary to my guess, this sparge has "pushed" a stuck mash to run off like normal. 4) The efficiency is the same as regular fly sparging.

Of course this sparge method is still in "trial" mode for me. I'm wondering what the cons would be.

 

[kanzimonson]

Well before you posted your results, I would have guessed that the only downside is the possibility of the grain bed getting too compacted. I'd say try it several more times and see if it always works. If so, sounds pretty good to me... I'd guess that a lot of people don't have the MLT capacity to have that much water on top of the grain bed.

 

[Northcalais40]

I would think that a stuck sparge would be influenced more by the flow rate out of the MLT than by the flow rate into it. I doubt that there is much difference in pressure between being under 20" of water and 28" of water. Any hydrodynamic experts listening? I have no idea about this stuff.

 

[beretta]

from my understanding of hydrodynamcis, 28" as compared to 20" of depth would give you around 28/20 times the pressure at the bottom of the tun, or 1.4 x. I also thought that the more weight of water would compact the bed more, but I'm not sure of the physics behind that... I think worse would be a large pressure differential supplied by running off too fast (e.i. wanging your valve open ). I'm going to do a few more batches like this and keep some records (always do) on the efficiency, and tastiness!

 

[Hex]

The only drawback that I can see is maxing out your tun. I can get 14 lbs of grain and a couple inches of sparge, no more, so I fly sparge.

If you think about it, the water is just a column of water with grain sunk in it. 2-10 inches of water above the grain should make no difference to the lauter. Flow rate and temperature are probably more important, but some here even question temperature...

It's an thermal and osmotic piston, and I believe if the sparge column is hotter than the mash/wort column, the hot water will tend to stay on top, but that's another thread...

 

[Hex]

After watching countless hours of the BP rovers, a mile under water, stirring up loose sediment on the seafloor makes me realize that there is no force differential between the top and the bottom of a submerged particle. Water above does not pack silt below, just settling with gravity. Flow rate, mash type and consistency, and maybe temperature are your main variables. Now get brewing...

 

[millaj92]

from my understanding of hydrodynamcis, 28" as compared to 20" of depth would give you around 28/20 times the pressure at the bottom of the tun, or 1.4 x. I also thought that the more weight of water would compact the bed more, but I'm not sure of the physics behind that... I think worse would be a large pressure differential supplied by running off too fast (e.i. wanging your valve open ).!

I'm not saying that I disagree with you, because technically you are correct, but when you're lautering in a 5 gallon or even a 10 gallon tun and using a 3/8" pick-up tube, I really don't think a pressure increase of 4% is going to make a noticeable difference, even if your 1/2" valve is all the way open. I know it certainly SOUNDS like a 40% percent increase in pressure would make a BIT of a difference, but not when you factor in the viscosity of the first running still in the tun, the energy lost by simply using a pick-up tube, and the resistance the grain bed adds. Besides, if the proper amounts/temperatures/volume is used, what's wrong with sparging a little too fast? Me thinks as long as the grain bed never goes dry you are golden.

(Disclaimer: This has been a statement of my opinion, and I claim that there are no facts here)

 

[kanzimonson]

I guess there's one question I have, regarding diffusion. If you put "pure" water on top of a mash, won't some of the sugar diffuse upwards into the pure water? I guess it's just a question of how much of a diffusion effect you get.

My guess is that it's pretty minimal, and once again, beretta's experiment indicates that it wasn't a big problem.

 

[rtichota]

After watching countless hours of the BP rovers, a mile under water, stirring up loose sediment on the seafloor makes me realize that there is no force differential between the top and the bottom of a submerged particle. Water above does not pack silt below, just settling with gravity. Flow rate, mash type and consistency, and maybe temperature are your main variables. Now get brewing...

Somewhat true. The pressure on a particle near the surface will be less than the pressure on a particle at the bottom. But I think the confusing part here is we're talking about pressure not force. Pressure will act to compress each particle (think implosion), whereas a downward force would compress a grainbed.

But you're right about the settling with gravity, and that flow rate, mash type, consistency, temperature seem to be the major players here.

 

[BigJoeBrews]

I think that as long as the grain bed is completely saturated or surrounded with water, the force is kind of distributed throughout. But if the grain is not completely saturated, then it would increase the force on the bottom..
I'm no fluid dynamics expert, this is only my guess!!

Can you maybe test this by putting a given amount of sand in each 5 gallon bucket, and a 55 gallon drum. Give them both a stir and see which settles first?
Do items in water sink faster as they get deeper? I don't think they do, but I'm not sure on this... If they don't, then I'd say the weight of the water has no effect?

 

[beretta]

Well, I'll be trying this again tomorrow. As far as dilution goes... I guess there is a couple of ideas why I'm not worried: 1. wort is denser: its lower temperature (158F) than sparge water (170F), and it's apparent SG is more. I last week's laudder of a stout, I could see the wort - water barrier plain as day until the wort droped below the grain bed. I'm not sure why I would be overly worried about osmotic dilution anyway... I only put in enough sparge water to get my preboil length, anyway. Usually, I'm off cleaning something, and know the sparge is done when I hear the MT go "gurgle-gurgle".

I only use a 5 gallon mash tun, and I can just squeeze in 10-13 lbs of grain, and a 1.25 qt/lb ratio's worth of water. Even so, the grain bed still settles to about 60-70% of MT volume during lauddering, and I can easily get 6-7 inches of sparge water into my small MT. If I had a 10 gal MT, I might be able to get the entire sparge water ontop of the mash in one fell swoop.

 

[statseeker]

Particles in water dont sink slower or faster the deeper they go unless they are less or more heavy than a comparable particle. Watch your grain trub particles fall through your beer when you stir it up. They dont get slower or faster as they reach the bottom they sink at the same rate. The reason the yeast particles dont sink as fast is because they are lighter and stay in suspension longer.

The 5-gal bucket 55-gallon drum experiment wouldnt really prove anything because the sand in the drum would have a longer distance to travel to settle out if I'm catching the point of the experiment right?

 

[BigJoeBrews]

Thats true, I'm just trying to stir up some ideas...
Pun intended!

 

[mikelikesit2000]

I would think that a stuck sparge would be influenced more by the flow rate out of the MLT than by the flow rate into it. I doubt that there is much difference in pressure between being under 20" of water and 28" of water. Any hydrodynamic experts listening? I have no idea about this stuff.

For every 12" of fluid head, PSI will increase by .441 PSI.

 

[Hex]

Is Grain bed depth is the critical variable?

 

[beretta]

For every 12" of fluid head, PSI will increase by .441 PSI.

That sounds about right... if I remember at 15 psi (weight of air at sea level) will push a column of water 32'.. so 15/32 = .45-ish psi per foot of water. I don't think PSI has any effect on the dynamics of lauddering, if you keep flow rate constant.

I guess, my thoery is: if you have the extra volume in your mash tun, you might as well fill it up with sparge water, just watch your flow rate.

 

[logdrum]

Somewhat true. The pressure on a particle near the surface will be less than the pressure on a particle at the bottom. But I think the confusing part here is we're talking about pressure not force. Pressure will act to compress each particle (think implosion), whereas a downward force would compress a grainbed.

But you're right about the settling with gravity, and that flow rate, mash type, consistency, temperature seem to be the major players here.

F=P*A
2.31'=1psi
do the math

Man I type slowly...

 

[beretta]

Is Grain bed depth is the critical variable?

Maybe. I'm thinking that the density of the grain bed and the depth would counteract the pressure of the extra water... sorta of an ohm's law type relationship. If you bed depth or density get too much, your flow will crawl to a stop. So rather than I=V/R, you would have Flow Rate = PSI / Mash "Resistance". Where the mash resistance would be some combination of the mash density x depth + valve. I'm sure the manifold, and exit tubing adds some resistance too. I think the bed density would be determined mostly by flow drag, where the grain bed density would be either proportional to or a square of the flow rate.

I'm more interested if the extra sparge water would effect efficiency. It would be neat to see just exactly how much flow rate you could get without loosing efficiency.

 

[OLDBREW]

haven't read the whole thread but.. I think it depends on your crush/ingredients used/and flow rate output.
The reason why they tell you to keep the grainbed covered with 1 or 2 inches above, for one is, with a sparge arm you can break up the silt on the top of the bed without creating channels, and 2.. if you put too much water on top of the grainbed the weigh of the water can compact the bed. The grainbed is supposed to float some during sparge, so your extraction between all the husks/particles, is more efficient.

When you get into higher poundage of grain, and/or certain ingredients, (like unmalted wheat) putting too much weight on top of the bed will compress the bed more, and can make runoff a nightmare. your mileage may vary

 

[BigJoeBrews]

F=P*A 2.31'=1psi Flow Rate = PSI / Mash "Resistance"

Now I'm really confused...force..pressure??
Is this pressure on the grain or the outer walls of your mash tun? Im thinking that the force(weight) of the water is all(or like 95-99%) going to the mash tun walls versus the grain. There is pressure on the individual grains, but this would be trying to collapse the pieces of grain (trying to implode them) not direct downward force because the water can move through the grains. Still I think with this amount of water, it would be negligible...
I think as long as you have good surface area on your filter (braid or false bottom) for the water to get to the valve, all the force will be on the valve and not the grain or the filter.
My biggest issue with dumping all you sparge water at once is temps. Are you closing the cooler once you dump the water in?
I live in chicagoland, very cold here(this time of year). I brew in my garage with the door slightly ajar for fresh air. It gets very chilly and I have to monitor the temp of the grains during the sparge. I notice I have to use a little hotter water at first to get my temp up, then I turn the flame way down during my sparge. I notice that if I start messing around alot with water flows my temp start varying a bit...
If you can get all your sparge water in your MLT, this might help me with this problem!!

 

[beretta]

The reason why they tell you to keep the grainbed covered with 1 or 2 inches above, for one is, with a sparge arm you can break up the silt on the top of the bed without creating channels,

Ok... I could see that being a disadvantage to my proposed mashing method. I remember from my days while taking care of a small pond: silt is amazingly floculant and will be a water proof barrier if you let it.

 

[OLDBREW]

Ok... I could see that being a disadvantage to my proposed mashing method. I remember from my days while taking care of a small pond: silt is amazingly floculant and will be a water proof barrier if you let it.

I wouldn't worry about it. I haven't used sparge arms(whirlygiggy) in more then a decade. If you start having problems with the silt part, just make cris cross slits in the bed with a knife about 2 " deep .

Running a herms system I played with bowls and perforated pie plate to diffuse the hose flow, I've been using a no splashy thingy that Zymie used and it works fine just sitting on top of the level grainbed.

As far as doing what you are doing... If it doesn't break, and you get good results, don't fix it!

 

[beretta]

Is this pressure on the grain or the outer walls of your mash tun? Im thinking that the force(weight) of the water is all(or like 95-99%) going to the mash tun walls versus the grain. There is pressure on the individual grains, but this would be trying to collapse the pieces of grain (trying to implode them) not direct downward force because the water can move through the grains.

Agreed. I'm saying that the downward force isn't due the the pressure, its the cause by *water flowing* in a downward direction and dragging the grains down with it.

My biggest issue with dumping all you sparge water at once is temps. Are you closing the cooler once you dump the water in?

I've never worried about temperature during sparging. Should I? I mash-out at what ever rest temp I ended up with (152F) and dump 170F water on top.

 

[DeafSmith]

I'm saying that the downward force isn't due the the pressure, its the cause by *water flowing* in a downward direction and dragging the grains down with it.

This seems right to me that the downward force isn't due to the pressure of the water column above it. If there were no flow, then the downward force on each individual particle would be its net weight, that is, its weight minus its bouyancy (weight of water which it displaces) plus the net weight of the grain above it. This would not depend at all on the depth of the water in which it was submerged. With flow through the grainbed, then you have the water drag added in.

 

[OLDBREW]

This seems right to me that the downward force isn't due to the pressure of the water column above it. If there were no flow, then the downward force on each individual particle would be its net weight, that is, its weight minus its bouyancy (weight of water which it displaces) plus the net weight of the grain above it. This would not depend at all on the depth of the water in which it was submerged. With flow through the grainbed, then you have the water drag added in.

the fun part is when you open the valve.

guys that were automating the systems using a pump, would have all their valves open. The pump cycled on and off during the brewin session. Problem was that every time the pump would come on, although the pump was gravity fed, with the very small amount of suction power, they would compact the grainbed from flow rate and have stuck sparge symptoms .

one of the work arounds for the problem was to add a lauter grant with float switches. The pumps intake hose was moved down to that. Then you could adjust the flow rate of the mashtun gravity filling the lauter grant and cycle the pump however without compaction of the bed.

downside was.. one more vessel the wort had to run through that equals more heat loss.
Zymies Automated Lauter Grant

 

[BigJoeBrews]

hey oldbrew, What you got in that lower picture there?
Zymies Automated Lauter Grant
Sorry for getting a little off topic, but I'm interested in whatcha got there.. I am looking for a good way to throttle my sparge water coming in.

 

[OLDBREW]

hey oldbrew, What you got in that lower picture there?
Zymies Automated Lauter Grant
Sorry for getting a little off topic, but I'm interested in whatcha got there.. I am looking for a good way to throttle my sparge water coming in.

Well I don't know if Zymie aka Wayne Holder from Zymico Inc. has put a patient on this or not, but by just looking at it, and from him personally telling me, the top fitting comes from the mashtun and fills the grant. the one to the right of that is a float switch. the one running across the bottom right to left is the pickup tube for the pumps intake.

Everthing is made up of 1/2" hard copper, 1/2" fittings/threaded and sweat, and 1/2" weld-b-gone or skotrats po mans keg conversion bulkhead fittings? The switch has mpt threads with wire leads coming out the threaded end, then gets routed out of the pot through copper to be hooked up to the pumps controller.
SS pot is the grant.

Zymie is/was a comm/industrial electrician at the time, so he knew his way around control work

here is Skotrats site link, with the Brewrats how we brew page for Zymie.
http://www.skotrat.com/go/default/brewrats/how-we-brew/zymie/

while your there take a peek at ElderRats page ER's perfesser

 

[beretta]

Here's today's results using my new sparge method:

7 lb 2row pale malt
.5 lb caramel malt
.5 lb roasted malt
.3 lb roasted barley
8.3 lbs total

Post-boil, I ended up with 5.1 gals of 1.050 point wort... so... 255 pt*gals. 255 / 8.3 gives 30.7 pts/gals*lbs. I'm figuring my theoretical max yield would be about 36 pts with this grain bill. Looks like I got 85% efficiency - what I always get.

I really opened up the laudder valve today, I had my BK full in 15 mintues. I was a little dismayed at how fast the wort turned watery, but then I noticed my BK was nearly full. It usually take 30-40 minutes for me to fill my BK.