speed of draining mash tun while bath sparging

[glang]

I batch sparge...I vorlauf pretty slow then I also empty my mash tun pretty slow before I pour in my sparge water. However, I was reading Denny Conn's recently website and he recommends to drain the mash tun as fast as possible.

1) What is the advantage of draining the mash tun as fast as possible?
2) Is it safe to drain it fast? Don't I risk sucking down the grain bed?

 

[Singletrack]

IIRC Denny says to drain as fast as your system will allow. For my system, I find it better to drain slowly. Still, I frequently get a stuck sparge. Usually this occurs after batch sparging to reach 168 F. If I score the top level of grain about halfway through the draining, it seems to help. Interested to read the experiences of others. Would like to drain faster!

 

[kh54s10]

I think that if you open wide it may compact the grain and create a stuck sparge. I do not have that problem. I vorlauf slowly, then pour it back. Then I open it a little more for a few seconds, then WIDE open. I have had no issues.

 

[snowtires]

I use a 3/8" valve wide open. Never a stuck sparge

 

[Singletrack]

So what's so different about my system that I must drain slowly and still get stuck? Round 10 gallon cooler with bazooka screen. I even condition grains to keep husks in tact. My crush is not too tight, ~0.039. Rarely use a lot of wheat or rye.

(Not my thread, but maybe this helps OP?)

 

[snowtires]

I found out that grain comes in all shapes and sizes depending on where it comes from. My grain (Gambrinus) crushes perfect at like .045

 

[MikeInMKE]

I use a round 10 gallon cooler with bazooka screen. I've never used wheat nor rye and have never had a stuck sparge.

I vorlauf slowly for the first gallon and a half (I use two containers so I can keep the flow going the whole time), then wide open during the second gallon and a half. Some bits make it through the bazooka screen and are held up by the partially open ball valve.

And then wide open into the brew kettle.

I did buy a stainless steel pizza pan with the intent of drilling a bunch of small holes into it so I could pour the vorlauf back in without disturbing the grains too much but never got around to finishing that project.

 

[Auger]

When I vorlauf and pour the the liquid back in, I float a plastic tupperware lid on top of the mash and pour on to that...it disperses the flow enough that it doesn't disturb the grain bed. I also drain the sparge water from the HLT to the MLT onto that for the same reason.

 

[captjpr]

I like the pizza pan idea. I think I have one someplace.

Thanks!

 

[Rev2010]

I also use a round Rubbermaid cooler with a bazooka tube and don't have stuck sparges even using wheat and other grains many caution stick sparges. Only ever had a stuck sparge with my first pumpkin since I didn't use rice hulls. So far pumpkins are the only beer I use rice hulls with and all has been good. I also have the 3/8" wide valve nozzle. I start opening slowly and let the wort start to run. A few seconds later I open it up full. I don't like the idea of opening it up all the way full right from the get-go and also agree there's probably a higher chance of compacting the grains negatively. I mean really, how much time does it save to open it full blast from the get-go vs. opening it up slowly for a few seconds till it's flowing smoothly then gently turning it to full open? But yeah, outside of starting the flow for runoff and sparges I run it full open.

As for vorlaufing, I just gently pour the wort back in along the wall of the tun. I press the mouth of the measuring cup I use closely up against the wall so it very gently streams down along the wall.


Rev.

 

[JustLooking]

I float a plastic tupperware lid on top of the mash and pour on to that...I also drain the sparge water from the HLT to the MLT onto that for the same reason.

This is odd, because you should be stirring after adding sparge water to your MLT and then vorlauf again before the second lauter.

 

[Singletrack]

When I get a stuck sparge, it is almost always after batch sparging -- not the initial lauter after mashing. I use hot water for the sparge to raise the temperature to 168 F (mashout temp). Does this increase in temp contribute to the problem, or do you wide-openers sparge at similar temp?

Otherwise, I am puzzled by this and may start my own thread. About the only thing I have left to blame is the 7000 ft elevation, but I have not heard of that affecting lautering -- just boil temp, carbonation, etc.

 

[helibrewer]

I batch sparge...I vorlauf pretty slow then I also empty my mash tun pretty slow before I pour in my sparge water. However, I was reading Denny Conn's recently website and he recommends to drain the mash tun as fast as possible.

1) What is the advantage of draining the mash tun as fast as possible?
2) Is it safe to drain it fast? Don't I risk sucking down the grain bed?

Whether batch or fly sparging, you want to drain as fast as the grain bed will allow. The only concerns in sparging are reasonably hot water (170-180) and not compacting the grain bed. Commercial breweries use wide, shallow lauter tuns to allow for fast sparging. Some of the largest use mash filters which make it a very fast operation.

 

[helibrewer]

When I get a stuck sparge, it is almost always after batch sparging -- not the initial lauter after mashing. I use hot water for the sparge to raise the temperature to 168 F (mashout temp). Does this increase in temp contribute to the problem, or do you wide-openers sparge at similar temp?

Otherwise, I am puzzled by this and may start my own thread. About the only thing I have left to blame is the 7000 ft elevation, but I have not heard of that affecting lautering -- just boil temp, carbonation, etc.

When you batch sparge you stir in fresh sparge water and destroy the filter bed. You need to begin by vorlaufing very slowly, repeatedly, until the grain bed re-settles, then you can increase the speed of the lautering.

 

[Singletrack]

Yes, that's what I do.

 

[Auger]

This is odd, because you should be stirring after adding sparge water to your MLT and then vorlauf again before the second lauter.

Sorry I should have specified....I fly sparge, not batch sparge.

 

[JustLooking]

Yes, that's what I do.

Right after stirring (and before vorlauf), try blowing into the tube connected to your MLT so that bubbles come up through the mash. Fine particles of grain can sometimes clog the screen. This reverse pressure can help to free it up and allows proper flow to start easier.

 

[mlafnitzegger]

I vorlauf 3/4 open on my 1/2 valve. I then open fully draining the mash tun. Stuck sparge can be caused by many factors; grain grind as well as type, manifold for filtering of your mash tun, how well you dough in to name a few. When I first started brewing I found that most of my stuck sparge issues were caused by using a bazooka due to the way it allows for channeling in the grain bed. I made my first manifold and only had sparging issues when I used wheat\oat. Then I just make sure to use rice hulls. I did finally go with a false bottom and have never had an issue since. Brewhardware.com has an excellent false bottom.

 

[Bobby_M]

When I get a stuck sparge, it is almost always after batch sparging -- not the initial lauter after mashing. I use hot water for the sparge to raise the temperature to 168 F (mashout temp). Does this increase in temp contribute to the problem, or do you wide-openers sparge at similar temp?

Otherwise, I am puzzled by this and may start my own thread. About the only thing I have left to blame is the 7000 ft elevation, but I have not heard of that affecting lautering -- just boil temp, carbonation, etc.

Do you have a piece of tubing hanging off the valve on the outside to keep the suction nice and strong?

 

[Singletrack]

Do you have a piece of tubing hanging off the valve on the outside to keep the suction nice and strong?

Yes, I have a length of BrewHardware silicone tubing from the MLT to the BK. Thanks.

 

[Singletrack]

Right after stirring (and before vorlauf), try blowing into the tube connected to your MLT so that bubbles come up through the mash. Fine particles of grain can sometimes clog the screen. This reverse pressure can help to free it up and allows proper flow to start easier.

I will give that a try! And of course I will hold the end of the tubing up above the level of the wort before I put my mouth on it and open the valve. Thank you for the suggestion!

 

[Singletrack]

I found out that grain comes in all shapes and sizes depending on where it comes from. My grain (Gambrinus) crushes perfect at like .045

I did try going to a coarser crush, and that helped. However, I saw that some whole grains were coming through the mill, and I just couldn't accept that. I started conditioning my grains -- lightly misting them with water before the crush -- and tightened up the crush. I get about 80% post-boil efficiency, which is great. Someone may want to suggest that I am greedy with efficiency and that's why I get stuck sparges. First of all, I like to think I am frugal, not greedy. Second, I have a hard time believing that the non-stuck crowd is using a crush that leaves whole grains uncracked. I seem to go from that to 80%.

Also, my grains are all types and sizes. My Barley Crusher isn't really that easy to adjust (it racks), so I want a roller spacing that is tight enough to crack a little rye and a big barley without changing spacing. If that's unreasonable, let me know, but my current setting seems to be okay for that. Sometimes I double crush the small grains.

I realize a double crush of wheat or rye exacerbates the stuck sparge problem, but I'm only using a small percentage of these grains, typically less than 10%.

Thank you.

 

[Auger]

Whether batch or fly sparging, you want to drain as fast as the grain bed will allow.

This confuses me, because everything I've read indicates that the drain rate of sparge water should be regulated to some degree. Palmer writes

Watch the outflow of wort, you do not want to lauter too fast, as this could compact the grainbed and you would get a stuck sparge. A rate of 1 quart/minute is the most common.

Followed by

If you have lautered too fast, you will not rinse the grains effectively and you will get poor extraction.

But it sounds like as long as you are getting good flow through the grainbed, you are just letting it rip? For some reason when I read about controlling the flow rate, I made the assumption that it was because the hot liquor coming into the MLT needed some sort of dwell time to further dissolve sugars, etc. It sounds like this is not the case, the only concern is keeping the grain bed fluid, so if you can do that while running wide open, that's not a problem?

 

[jfk69]

I'm with Auger on this one. I actually drain my sparge water very slowly (batch sparging), as I get much better extraction from the slower draining. Since I went to a pint (or less) a minute, I have seen my efficiency improve tremendously. To each their own. FWIW, I use a false bottom in a 10 gallong Igloo cooler. Unless I start getting stuck sparges I plan to continue my current practice.

 

[Bobby_M]

I have attempted to push the sparge/drain rate while fly sparging to run off around 7 gallons in 30 minutes but that's pretty much the limit if I don't want to compact the grain bed. When you say "as fast as the grain bed will allow" is not something you can really determine on the fly and still get away with it without stirring everything up and getting it running again. In terms of fly sparging, that's a failure. That's why it's just best to limit the rate to about 1qt / minute.

Now, batch sparging is a different beast in that you're not trying to flow the entire sparge volume through the grain and contact time as lower gravity wort encounters higher gravity grain is not even a working principal. Batch sparging is a diffuse to dilute process and once that sparge water has been stirred in real well, the only thing left is the separation. Drain it as fast as you can. I see people claim increased extraction when draining a batch sparge slower and the only explanation is that the increased heat is either finishing up some lagging conversion or reaching just a little deeper into the most coarse of grain bits. Of course, the proof is in the results really and whatever the explanation is, I can see sticking with what works for the individual.

Note: Palmer regularly makes blanket statements about sparging that are only specific to fly sparging yet he doesn't say that. It's especially confusing when it's intermixed with short mentions of batch sparging.

 

[Auger]

Now, batch sparging is a different beast in that you're not trying to flow the entire sparge volume through the grain and contact time as lower gravity wort encounters higher gravity grain is not even a working principal. Batch sparging is a diffuse to dilute process and once that sparge water has been stirred in real well, the only thing left is the separation. Drain it as fast as you can. [snip]
Note: Palmer regularly makes blanket statements about sparging that are only specific to fly sparging yet he doesn't say that. It's especially confusing when it's intermixed with short mentions of batch sparging.

Ok. This makes sense. Thanks for the clarification.

 

[Auger]

double post.

 

[Hamaki]

The main problem I've had is a clogged dip tube under the false bottom. I recirc through a HERMS but after doughing in & a vigorous stir, getting the flow started can be a PITA. Rather than blowing, because sometimes I can't generate enough pressure, I pinch off the silicone tube and then fold back & forth toward the MLT, building back pressure that way. It works but is time consuming. I've had the same problem after batch sparging. Too much grain making it through or around the false bottom, I guess. Thinking of trying a bag.

 

[helibrewer]

Breweries are concerned with one thing when lautering...rate of flow. This is because they have another batch to process and if you lautered a 10bbl system at 1qt/min you would be brewing once a week.

You can rinse grain effectively at any speed so the concern is grain bed compaction.

rate of flow = pressure X bed permeability X filtration area

bed depth X wort viscosity​

 

[Homercidal]

I tend to drain as quickly as I can. With batch sparging there is no need to waiting around. I've had some wort remain on top of the grian bed from running off too fast. The problem is that after adding sparge water and stirring, all of the heavy grains sink quickly, with the really fine stuff settling after. This leaves a layer of fine dust on top, which doesn't allow the wort to run through quickly. I simply poke a few holes on the surface to let it drain through.

The faster you get the wort out when batch sparging, the faster you can get it in the BL and start heating it for the boil.

 

[Bobby_M]

Breweries are concerned with one thing when lautering...rate of flow. This is because they have another batch to process and if you lautered a 10bbl system at 1qt/min you would be brewing once a week.

You can rinse grain effectively at any speed so the concern is grain bed compaction.

rate of flow = pressure X bed permeability X filtration area

bed depth X wort viscosity​

I agree, but we're homebrewers doing typical 5-10 gallon batches. A slightly slower lauter is the difference of 10 minutes. When we brew on our club's 100 gallon mash tun for a 60 gallon batch, we fly sparge at about 1 gallon per minute and it makes sense because the open area of the false bottom is about 4x that of a 15" diameter "homebrew" sized tun/false bottom.

 

[Gus_13]

In my experiences, my efficiency has gone up with a slow sparge. I batch sparge most of the time but I'm in no rush so I let it drain out slowly. Maybe just me or may not even be true but I know my efficiency went up when I went to going slow. I have a 10 gallon round cooler with a false bottom that has 3/8" tubing. This goes into a 1/2" ball valve and a 1/2" cam-lock connector.

I use tin foil laying on the top of the grain bed to vorlauf. Keeps the grain bed from being disturbed and lets me pseudo fly sparge in the beginning so I don't have to dump so much in there.

 

[Bobby_M]

What's a psuedo fly sparge? If you are mixing techniques, then observed facts about batch sparging would not necessarily apply.

 

[Gus_13]

What's a psuedo fly sparge? If you are mixing techniques, then observed facts about batch sparging would not necessarily apply.

I mean it as I'm running the first little big of sparge water onto the grain bed as the first runnings are finishing. Then I dump the rest and let it settle for 10-15 minutes before second runnings. It just makes the HLT kettle easier to dump in the mash tun. Not actually fly sparging as it's still really batch sparging.