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General Category => All Grain Brewing => Topic started by: miguelpanderland on December 10, 2010, 03:57:53 pm

Title: Mash Out?
Post by: miguelpanderland on December 10, 2010, 03:57:53 pm
In a single step infusion mash what is the value of mashing out at a higher temp before sparging?  How do you know if you need to do this?
Title: Re: Mash Out?
Post by: denny on December 10, 2010, 04:10:45 pm
If you batch sparge, there may be little value in terms of the traditional reason you do a mashout, which is to fix wort fermentability.  If you fly sparge, that might be different.  I seldom do a real mashout step any more, but I do sparge with hot enough water that my grain bed usually gets up to mash out temps.  I've found that raising the temp ensures complete conversion and has improved my efficiency.
Title: Re: Mash Out?
Post by: mabrungard on December 10, 2010, 04:11:01 pm
The primary reason is to improve the overall mashing efficiency.  I see 8 or more points of additional gravity with a ~168F mash out step.  It further reduces the wort viscosity and extracts a little more out of the grist.  A mash out is always worth it in my opinion.
Title: Re: Mash Out?
Post by: miguelpanderland on December 10, 2010, 04:37:27 pm
How does re-circulating the wort for improved clarity tie in with this?

Should I re-circulate after I've raised to mash-out temp or between the 60 min rest and the mash-out?
Title: Re: Mash Out?
Post by: tygo on December 10, 2010, 04:39:25 pm
I've been thinking about this as well lately.  I batch sparge but by the time I runoff the wort into the kettle it's sitting there for quite awhile at around 140F (or lower).  I routinely raise the temperature at the end of the mash to around 160F to make help make sure I have complete conversion but there's likely still some beta left around even after that.

I have to imagine that whatever beta that's still around is continuing to do it's thing in the kettle until I start heating it up for the boil.

My attenuation tends to be a little on the high side of what I'm shooting for, even with higher mash temps, so with the next few batches I'm going to try a mashout rest at around 170F for about 10-15 minutes and see what that does.
Title: Re: Mash Out?
Post by: denny on December 10, 2010, 04:51:25 pm
How does re-circulating the wort for improved clarity tie in with this?

Should I re-circulate after I've raised to mash-out temp or between the 60 min rest and the mash-out?

I only recirculate when I do a runoff.
Title: Re: Mash Out?
Post by: gordonstrong on December 10, 2010, 04:55:30 pm
Beta amylase works at lower temperatures than alpha amylase.  The mnemonic I use is beta = before, alpha = after.

But I don't think that's the real issue.

Presumably, you're mashing out after conversion is complete.  The extra extract you get from mashing out has more to do with doing a better job of dissolving the sugars so they more easily run off than anything else.  You aren't converting more sugars; you're just leaving less of them in the mash tun.
Title: Re: Mash Out?
Post by: miguelpanderland on December 10, 2010, 05:07:22 pm
How does re-circulating the wort for improved clarity tie in with this?

Should I re-circulate after I've raised to mash-out temp or between the 60 min rest and the mash-out?

I only recirculate when I do a runoff.

So when your moving the wort from mash tun to boil kettle?
Title: Re: Mash Out?
Post by: Kaiser on December 10, 2010, 05:14:11 pm
The extra extract you get from mashing out has more to do with doing a better job of dissolving the sugars so they more easily run off than anything else.  You aren't converting more sugars; you're just leaving less of them in the mash tun.

I have been challenging the idea that the mash-out’s efficiency gain comes from less wort viscosity and better dissolving of sugars.

The gains that some brewers see from doing a mash-out are too big to be explained by this. I think that if you are seeing substantial efficiency gains from a mash-out (>5% or example) your mash wasn’t done converting before the mash-out. You can easily test this with a mash gravity test (http://braukaiser.com/wiki/index.php/Troubleshooting_Brewhouse_Efficiency#Determining_Conversion_Efficiency) . There have been a number of mashes in my past where the conversion efficiency was 90-95% before I did the mash-out and it was close to 100% 10-15 min into the mash-out.

FWIW, you can sparge with cold water w/o impacting your efficiency significantly.

Kai
Title: Re: Mash Out?
Post by: tygo on December 10, 2010, 05:31:14 pm
For the people that are seeing a significant increase in efficiency by doing a mash out step I wonder if they'd get the same efficiency by stirring the mash alone and adding just enough hot water to maintain their mash temp.  It might be that the stirring improves the access of the enzymes to the remaining starches.
Title: Re: Mash Out?
Post by: bluesman on December 10, 2010, 05:41:31 pm
This is an interesting discussion.

I haven't used a mashout as I was always led to believe it's not worth the effort in terms of added benefit but I am now uncertain. There isn't any convincing data that I have seen to prove one way or the other that it can increase efficiency or fermentability? I would employ a mashout if there was a significant benefit from the use of one.

Maybe Kai can conduct some experiments to the liking.  :-\
Title: Re: Mash Out?
Post by: miguelpanderland on December 10, 2010, 05:51:58 pm
Beta amylase works at lower temperatures than alpha amylase.  The mnemonic I use is beta = before, alpha = after.

But I don't think that's the real issue.

Presumably, you're mashing out after conversion is complete.  The extra extract you get from mashing out has more to do with doing a better job of dissolving the sugars so they more easily run off than anything else.  You aren't converting more sugars; you're just leaving less of them in the mash tun.

So then we can understand the mash out as an aid to the sparging process?  So maybe it's not something you want to do all the time but moreso with mashes the adjuncts that lend themselves to getting stuck?
Title: Re: Mash Out?
Post by: denny on December 10, 2010, 07:30:59 pm
The extra extract you get from mashing out has more to do with doing a better job of dissolving the sugars so they more easily run off than anything else.  You aren't converting more sugars; you're just leaving less of them in the mash tun.

I have been challenging the idea that the mash-out’s efficiency gain comes from less wort viscosity and better dissolving of sugars.

The gains that some brewers see from doing a mash-out are too big to be explained by this. I think that if you are seeing substantial efficiency gains from a mash-out (>5% or example) your mash wasn’t done converting before the mash-out. You can easily test this with a mash gravity test (http://braukaiser.com/wiki/index.php/Troubleshooting_Brewhouse_Efficiency#Determining_Conversion_Efficiency) . There have been a number of mashes in my past where the conversion efficiency was 90-95% before I did the mash-out and it was close to 100% 10-15 min into the mash-out.

FWIW, you can sparge with cold water w/o impacting your efficiency significantly.

Kai


Kai, I agree with you.  I tried the cold sparge both with and without raising the mash temp first.  I found that raising the temp provided an efficiency boost with the cold sparge, but not raising the temp didn't.
Title: Re: Mash Out?
Post by: Kaiser on December 10, 2010, 07:47:00 pm
Kai, I agree with you.  I tried the cold sparge both with and without raising the mash temp first.  I found that raising the temp provided an efficiency boost with the cold sparge, but not raising the temp didn't.

That nice. Did you post about this experiment. It seems more comprehensive than what I did.

Kai
Title: Re: Mash Out?
Post by: MDixon on December 10, 2010, 08:24:04 pm
I'm about wiped out from travel, but let me be sure I am clear on what is being said. ?The sparge water in a fly sparge can be cool for post mashout sparging? ?What is cool? ?What were the procedures?

?Are you saying conversion efficiency would not suffer (understandable) or saying brewhouse/mashouse efficiency would not suffer (not so easy to grasp)?



FWIW - I have long wanted to sparge using hot water from a tankless hot water heater ~130F to see what would happen. I have the ability to now do just that, but haven't had the time to try it. I was thinking of mashing out and then sparging with the 130F water. The beauty is it would only take a small amount of water discard before the temp reached max temp and then no additional heat would be needed from a burner.
Title: Re: Mash Out?
Post by: denny on December 10, 2010, 08:32:34 pm
Kai, I agree with you.  I tried the cold sparge both with and without raising the mash temp first.  I found that raising the temp provided an efficiency boost with the cold sparge, but not raising the temp didn't.

That nice. Did you post about this experiment. It seems more comprehensive than what I did.

Kai

Nope, I didn't post.  It was just curiosity.  I used 2 consecutive batches of rye IPA since I make it so often and it's so consistent.
Title: Re: Mash Out?
Post by: denny on December 10, 2010, 08:34:21 pm
I'm about wiped out from travel, but let me be sure I am clear on what is being said. ?The sparge water in a fly sparge can be cool for post mashout sparging? ?What is cool? ?What were the procedures?

Mike, both Kai and I batch sparge.  The water I used was maybe 55-60F.  As I said, I didn't do a lot of documentation since I was just curious to see what would happen.
Title: Re: Mash Out?
Post by: Mikey on December 10, 2010, 09:22:26 pm
Next time you get your hands sticky from syrup or some other sugar substance, rinse one with cold water and the other with warm. The warm one will be clear of sugar faster.

I think you can cold sparge in a pinch, but there's no real advantage to doing it all the time.
Title: Re: Mash Out?
Post by: denny on December 10, 2010, 09:24:25 pm
No one said there was any advantage to it.  It's just proving there's no disadvantage and the comparison to syrup doesn't work here.
Title: Re: Mash Out?
Post by: Kaiser on December 10, 2010, 09:52:58 pm
Syrup is much thicker than wort. And while there might be efficiency benefits to using hit water I don't think that they are more than 1%. That 1% means much to commercial brewers but it's easily in the noise for home brewers.

Kai
Title: Re: Mash Out?
Post by: Mikey on December 10, 2010, 10:17:43 pm
OK then dip both hands in concentrated wort, let dry and rinse. Warm water will rinse it faster, IMO.
Title: Re: Mash Out?
Post by: narvin on December 10, 2010, 10:33:48 pm
OK then dip both hands in concentrated wort, let dry and rinse. Warm water will rinse it faster, IMO.

Maybe if you're rinsing wort sugars that have dried on your hand... which would be just as concentrated as syrup.

I haven't done the math, but I don't think sugar solubility / saturation point in 170 vs colder water makes much difference at all with the concentration at sparge time.
Title: Re: Mash Out?
Post by: Mikey on December 11, 2010, 12:16:00 am
I can probably brew beer standing on one leg, but what's the point? I'll be heating my sparge water while I mash, so the wort going into my tun is hotter, IE shorter brew day.

In the end, I'll have my feet up in the air drinking a cold beer, while you're still cleaning up.  :D
Title: Re: Mash Out?
Post by: Mark G on December 11, 2010, 12:38:26 am
OK then dip both hands in concentrated wort, let dry and rinse. Warm water will rinse it faster, IMO.
True, but who lets their mash dry before sparging? Now THAT would be a long brew day.  ;)
Title: Re: Mash Out?
Post by: Mikey on December 11, 2010, 12:51:21 am
OK then dip both hands in concentrated wort, let dry and rinse. Warm water will rinse it faster, IMO.
True, but who lets their mash dry before sparging? Now THAT would be a long brew day.  ;)

Good point.
Title: Re: Mash Out?
Post by: denny on December 11, 2010, 01:37:28 am
I can probably brew beer standing on one leg, but what's the point? I'll be heating my sparge water while I mash, so the wort going into my tun is hotter, IE shorter brew day.

In the end, I'll have my feet up in the air drinking a cold beer, while you're still cleaning up.  :D

What you seem to be missing is that's it's an experiment to gain knowledge as opposed to a technique you'd use in everyday brewing.  The purpose is to find out if a mash temp increase leads to lower viscosity and better flow of wort.  The indications are that it does not, but that doesn't mean I'll be sparging with cold water.  Unlike someone who's never tried that experiment, I now have personal data to draw on.
Title: Re: Mash Out?
Post by: bluesman on December 11, 2010, 03:39:50 am
Hopefully we will better understand this technique someday. Personally, I would be really interested in some experimentation done to prove the effects of a mashout on efficiency and fermentability. If there were only thirteen months in a year I could possibly find the time to git-r-done.  ;)  8)
Title: Re: Mash Out?
Post by: Mikey on December 11, 2010, 12:34:36 pm
I can probably brew beer standing on one leg, but what's the point? I'll be heating my sparge water while I mash, so the wort going into my tun is hotter, IE shorter brew day.

In the end, I'll have my feet up in the air drinking a cold beer, while you're still cleaning up.  :D

What you seem to be missing is that's it's an experiment to gain knowledge as opposed to a technique you'd use in everyday brewing.  The purpose is to find out if a mash temp increase leads to lower viscosity and better flow of wort.  The indications are that it does not, but that doesn't mean I'll be sparging with cold water.  Unlike someone who's never tried that experiment, I now have personal data to draw on.

I understand that it was just an experiment, but I don't don't see the merits of it in brewing. Someone could measure the effects of butterfly farts on the environment and they might even find that they're detrimental, but in the end, butterflies will continue to fart. :D

And for what it's worth, long before I ever read this thread, I sparged my mash with additional warm (approx. 110F) water to extract a little more wort for a starter. It got me what I wanted, but as to the level of efficiency, I couldn't say nor did I really care at the time. So, based on what is described here, if I ever do it again, I can rest assured that I'm actually getting good extraction after all.  Thanks.
Title: Re: Mash Out?
Post by: 4swan on December 11, 2010, 03:27:00 pm
In a single step infusion mash what is the value of mashing out at a higher temp before sparging?  How do you know if you need to do this?

I know this doesn't chime in on the cold sparging, but I thought I'd add something from a fly sparger.  For a while I added hot water to bring up the mash to 165F before I started sparging. I stopped doing that, and now just sparge with water at 165-170.  I did not notice any change in efficiency or fermentabilty by removing the mash out step.
Title: Re: Mash Out?
Post by: Kaiser on December 12, 2010, 03:26:47 am
I don't think that the mash -out does much with respect to locking in the fermentability of the wort. After 60 min at 150-155F, there won't be much b-amylase left anyway, And that is primarily the enzyme that the mash-out is supposed to denature.

Kai
Title: Re: Mash Out?
Post by: tygo on December 12, 2010, 03:54:20 am
How much is not much though?  After mashing at say 154F for 60 minutes how much b-amylase is left?  If it takes awhile to run off the wort into the kettle and the wort is sitting there at 140F for half an hour or so, isn't that beta going to continue to work?  It seems to me like it would.  I don't know how much impact having 10% of the original b-amylase running for 30 minutes in the wort would have, but it feels to me like it would have some impact.

Maybe I'm wrong but I'm having issues with my attenuation being a bit higher than I would like.  I'm going to try a mashout step to see if I can mitigate that.
Title: Re: Mash Out?
Post by: denny on December 12, 2010, 04:10:52 am
Seems like it would be a lot more controllable to just raise your mash temp.
Title: Re: Mash Out?
Post by: Kaiser on December 12, 2010, 01:33:20 pm
Seems like it would be a lot more controllable to just raise your mash temp.

That's what I was going to suggest as well.

If the process consistent, I.e. the wort always sits for about the same time at about the same temp, rising the mash temp can also help with lowering the wort fermentability.

But you may also try a mash-out.

Kai
Title: Re: Mash Out?
Post by: tygo on December 12, 2010, 01:53:31 pm
I'm going to do that as well but I want to try to minimize the amount of enzyme activity that's occurring in the kettle.
Title: Re: Mash Out?
Post by: Podo on December 12, 2010, 10:35:01 pm
The only time I use a mash out is when I'm brewing a wheat or rye beer to let the wort flow a little better.  I've also done one a few times when I screwed up my water calculations  >:(.  It would seem logical that a mash out would increase efficiency, because water can dissolve more sugar at higher temps, but if your sparge is higher temp than your mash, it seems like it should all even out.
Title: Re: Mash Out?
Post by: tomsawyer on December 16, 2010, 07:16:47 pm
Is the increase in efficiency seen with a mashout due to stimulation of alpha amylase, or better gelatinization of suspended starch particles that were big enough to prevent complete solubilization/gelatinization?

The solubility of sucrose in water at 65C versus 20C is 50% greater (300g in 100ml versus 200g in 100 ml).  The sugar concentration in a batch sparge is typically 1/3 of what the mash conc was, so a decreased solubility still won't cause anything to drop out.  Plus the sugar is already dissolved and so you don't need the increased entropy from hot water to break the crystals down and dissolve them.
Title: Re: Mash Out?
Post by: Kaiser on December 16, 2010, 08:24:09 pm
Is the increase in efficiency seen with a mashout due to stimulation of alpha amylase, or better gelatinization of suspended starch particles that were big enough to prevent complete

It might be a combination of both. And if you infuse water for the mash-out, the reduced mash thickness also helps.

Barley has large and small starch granules. The small ones make up about 10% of the starch but require a higher temp to gelatinize than the large granules. As you heat the mash you’ll keep releasing starch, albeit in decreasing quantities, which is why you have to make sure that you don’t heat the mash above 175 F. At that point you would denature the a-amylase and with it the mash’s ability to break down the released starch.

Kai
Title: Re: Mash Out?
Post by: CASK1 on December 17, 2010, 02:38:41 am
What are everyones procedures for a mashout? I used to use a SS kettle as my mash tun, and could add direct heat to raise mash temp or do a mash out. I've since gone to an Igloo cooler mash tun, and only raise temp by addition of hot water. It seems a true mashout would require a large addition of boiling water, or does anyone do decoction-style mashouts? Any ideas are welcome!
Title: Re: Mash Out?
Post by: Kaiser on December 17, 2010, 03:16:06 am
I have gone from mashing in a cooler to direct heat mashing on the stove. Wrapping the pot in blankets or a sleeping bag holds the temp during rests.

Kai
Title: Re: Mash Out?
Post by: gordonstrong on December 17, 2010, 02:39:47 pm
It's going to depend on your equipment.  I can direct fire my mash tun, so that's what I do (while recirculating, so as to keep the temperature gradient low).

When I used to use a cooler, I'd infuse boiling water.

I've done decoction style mashouts, taking the thin portion of the mash and boiling it, then infusing it back in.  That will definitely stop enzymatic activity since the enzymes will be in the thin portion and boiling will denature all of them.

All of them work.  What you pick is up to you; what works best on your system and what your goals are.

If you have room for the boiling water, I'd think that would be the easiest.  Don't worry about mash thickness.  You're done mashing.  Now your concern is whether the additional weight will have impact on your lautering.
Title: Re: Mash Out?
Post by: Kaiser on December 17, 2010, 03:46:18 pm
Now your concern is whether the additional weight will have impact on your lautering.

Gordon, how would the additional water weight impact lautering? Is it because the increased water column causes a faster flow rate?

Kai
Title: Re: Mash Out?
Post by: gordonstrong on December 17, 2010, 03:59:20 pm
Just a general concern that a lot of water sitting on top of your grain bed can compact it.  I wish it would cause a faster flow rate  ;)  I'm concerned about the flow rate going to zero.

It's not a problem for most beers, and it's something batch spargers deal with all the time.  But I'm thinking about my weizens and other beers where I don't have as much filter material as usual.

Just something to watch.  There are obviously ways to mitigate the problem.
Title: Re: Mash Out?
Post by: Kaiser on December 17, 2010, 04:47:05 pm
Once all the grain is submerged and nothing is flowing yet, the column of water on top of it does not affect how much it is compressed. It could only have an effect if there are air pockets in the grain which would get compressed.

As the wort starts flowing there will be a pressure difference between the bottom and top of the grain bed and that pressure difference compacts the grain bed. This pressure difference depends on the porosity and depth of the grain bed and the flow rate. The latter is what you’ll have to adjust to prevent the mash from getting stuck.

Kai

Title: Re: Mash Out?
Post by: bonjour on December 17, 2010, 06:02:03 pm
I fly sparge most of my beers.  I will go up to about 4 gallons above my grain bed on occasions with no ill effects

Sometimes  see that the grain bed is floating so I let it settle on to the false bottom  and initially I'll drain until the wort level goes just below/at the surface of the grain bed.  After that I add my sparge water usually at least 12 inches above the grain bed.  Never had a problem.
Title: Re: Mash Out?
Post by: mabrungard on December 17, 2010, 06:08:29 pm
Um guys, it doesn't matter if there was a million feet of water column over the grain bed as long as there is no flow through the bed.  The net downward force on the grain bed is the same as if there was 1 inch of water of the grain bed.  Its when there is flow that the stress on the grain bed can go up some.

In this case, there is a concept called Effective Stress that applies here.  This is a primary concept to geotechnical engineering, which is what my first Masters degree is in.

As was alluded to by the comments, we know that the pressure applied by the water increases as we go deeper under the water surface.  But that water pressure doesn't just act on the top of the grain bed, it acts on each grain within the grain bed too.  So to simplify, consider a single grain that is small so that the water pressure at the top of the grain is roughly the same as at the bottom of the grain. 

Since water pressure always acts perpendicular to the surface to which it is applied and since there is equal upward facing surface area as downward facing surface area, the net effect is that the water force acting downward on a particle is the same as the water force acting upward on that particle when there is no flow. 

The force imposed by flow is another matter and the depth of the water column over the bed can have an effect.  As I mention above, the pressure on the top of the bed is roughly the same as on the bottom of the bed when there is no flow.  To cause flow, you have to have a pressure gradient across the bed.  For our tuns, we open a valve that is connected to the outside world where the water pressure is essentially zero.  If we open the valve a crack, we can keep the pressure at the bottom of the bed only a little lower than the pressure at the top.  But, if we open the valve all the way, we could get close to zero water pressure at the bottom of the bed.  This is where the depth of the water column over the bed plays a part. 

If I've got a million feet of water head over the grain bed and I make a mistake and open the valve too much, then I could be placing a 1,000,000' - 0' = 1,000,000 feet of head on the grain bed.  But if I only have a foot of water over the grain bed, then the worst I could do is apply 1' - 0' = 1 foot of head on the grain bed.   

So, its not really that putting a lot of water over your grain bed is bad.  Its that you could place a lot of stress on the grain bed if you open the outlet valve too much and draw off wort too fast.

So its not the water's fault, its the operator's fault. 

And regarding the issue with Batch spargers, they are draining all the wort from the bed.  Recall that I mentioned that the water pressure acts on all surfaces.  As we drain the bed, then a portion of the bed is above the liquid surface and instead being partially supported by the water pressure, that grain is applying all its soggy weight to the rest of the bed.  That can certainly compress the bed and is a good reason why you should not perform batch sparging.  Don't drain the bed until the final runoff.
Title: Re: Mash Out?
Post by: gordonstrong on December 17, 2010, 06:10:12 pm
Yeah, I usually fly sparge too, but I've had occasional problems with output when the water builds up on top.  Glad to hear it isn't widespread.
Title: Re: Mash Out?
Post by: dak0415 on December 17, 2010, 06:54:41 pm
I fly sparge most of my beers.  I will go up to about 4 gallons above my grain bed on occasions with no ill effects

Sometimes  see that the grain bed is floating so I let it settle on to the false bottom  and initially I'll drain until the wort level goes just below/at the surface of the grain bed.  After that I add my sparge water usually at least 12 inches above the grain bed.  Never had a problem.
Fred,
Do you acidify your sparge water, or is your water very soft?
Title: Re: Mash Out?
Post by: bonjour on December 17, 2010, 07:44:48 pm
Very soft Great Lakes water, approaching Pilzen
Title: Re: Mash Out?
Post by: denny on December 17, 2010, 09:57:33 pm
And regarding the issue with Batch spargers, they are draining all the wort from the bed.  Recall that I mentioned that the water pressure acts on all surfaces.  As we drain the bed, then a portion of the bed is above the liquid surface and instead being partially supported by the water pressure, that grain is applying all its soggy weight to the rest of the bed.  That can certainly compress the bed and is a good reason why you should not perform batch sparging.  Don't drain the bed until the final runoff.

Maybe from a theoretical standpoint, but in 389 batch sparges, it's never happened to me.  The odds are in my favor, Marin.
Title: Re: Mash Out?
Post by: Mikey on December 17, 2010, 10:09:27 pm
And regarding the issue with Batch spargers, they are draining all the wort from the bed.  Recall that I mentioned that the water pressure acts on all surfaces.  As we drain the bed, then a portion of the bed is above the liquid surface and instead being partially supported by the water pressure, that grain is applying all its soggy weight to the rest of the bed.  That can certainly compress the bed and is a good reason why you should not perform batch sparging.  Don't drain the bed until the final runoff.

Maybe from a theoretical standpoint, but in 389 batch sparges, it's never happened to me.  The odds are in my favor, Marin.

Science isn't always the final word, is it?  :D
Title: Re: Mash Out?
Post by: tubercle on December 17, 2010, 10:15:32 pm
And regarding the issue with Batch spargers, they are draining all the wort from the bed.  Recall that I mentioned that the water pressure acts on all surfaces.  As we drain the bed, then a portion of the bed is above the liquid surface and instead being partially supported by the water pressure, that grain is applying all its soggy weight to the rest of the bed.  That can certainly compress the bed and is a good reason why you should not perform batch sparging.  Don't drain the bed until the final runoff.

Maybe from a theoretical standpoint, but in 389 batch sparges, it's never happened to me.  The odds are in my favor, Marin.

Science isn't always the final word, is it?  :D

  It actually does compress...and squeezes all the sugary goodness out of the grain. ;D
Title: Re: Mash Out?
Post by: denny on December 17, 2010, 10:28:14 pm
Science isn't always the final word, is it?  :D

When experience disagrees, experience wins. 
Title: Re: Mash Out?
Post by: narvin on December 17, 2010, 10:57:02 pm

And regarding the issue with Batch spargers, they are draining all the wort from the bed.  Recall that I mentioned that the water pressure acts on all surfaces.  As we drain the bed, then a portion of the bed is above the liquid surface and instead being partially supported by the water pressure, that grain is applying all its soggy weight to the rest of the bed.  That can certainly compress the bed and is a good reason why you should not perform batch sparging.  Don't drain the bed until the final runoff.

This is a good reason why you should not perform batch sparging?  Really?  Even if people who batch sparge all the time generally have no trouble with grain compression during lautering?  And even if they did, would it not be prudent to investigate ways to mitigate this problem (wider, shallower mash tun, or rice hulls) before coming to this conclusion? 

It really amazes me how many scientists let their preconceptions color their results.
Title: Re: Mash Out?
Post by: Mikey on December 17, 2010, 11:00:04 pm
Science isn't always the final word, is it?  :D

When experience disagrees, experience wins. 

And the very reason we should be open to ALL suggestions and comments made by brewers, regardless of their backgrounds or experimental procedures.
Title: Re: Mash Out?
Post by: kerneldustjacket on December 17, 2010, 11:19:46 pm
Science isn't always the final word, is it?  :D

When experience disagrees, experience wins. 

And the very reason we should be open to ALL suggestions and comments made by brewers, regardless of their backgrounds or experimental procedures.

Yep. I'll bet the first guy to suggest that the world is round was soundly thumped by his friends...but we know now he was a visionary! (Though maybe an ex-communicated visionary) ::)
Title: Re: Mash Out?
Post by: tschmidlin on December 18, 2010, 05:10:58 am
Science isn't always the final word, is it?  :D
When experience disagrees, experience wins. 
Science is never wrong, just scientists :)

Martin makes a valid point, it just might not apply on a homebrew scale because the bed depth is probably 2 feet at most for the large majority of us.  Batch sparging on a 30 bbl system might not be so smooth and easy as homebrewers find it to be.  In all of these discussions people need to keep in mind that the equipment itself makes a difference, not just the procedures.

Yep. I'll bet the first guy to suggest that the world is round was soundly thumped by his friends...but we know now he was a visionary! (Though maybe an ex-communicated visionary) ::)
That the Earth is round and orbits the sun was known by the Greeks long before anyone was being excommunicated. :)
Title: Re: Mash Out?
Post by: Mikey on December 18, 2010, 05:12:49 am
The world is flat where I live.
Title: Re: Mash Out?
Post by: tschmidlin on December 18, 2010, 05:14:02 am
And I, for one, welcome our intergalactic overlords. ;D
Title: Re: Mash Out?
Post by: kerneldustjacket on December 18, 2010, 02:21:21 pm
That the Earth is round and orbits the sun was known by the Greeks long before anyone was being excommunicated. :)

And the Greeks gave us the starting point for Western philosophy, and so improved our ability to debate homebrewing philosophy.  :D

The world is flat where I live.

Love it! Deadpan humor deserves a rim shot: http://instantrimshot.com/classic/?sound=rimshot
Title: Re: Mash Out?
Post by: bluesman on December 18, 2010, 02:58:43 pm
And regarding the issue with Batch spargers, they are draining all the wort from the bed.  Recall that I mentioned that the water pressure acts on all surfaces.  As we drain the bed, then a portion of the bed is above the liquid surface and instead being partially supported by the water pressure, that grain is applying all its soggy weight to the rest of the bed.  That can certainly compress the bed and is a good reason why you should not perform batch sparging.  Don't drain the bed until the final runoff.

So if I hear you correctly Martin, what you are saying is that as the grain bed becomes exposed to the atmosphere during lautering, the wort logged grain portion exposed to the atmosphere applies a downward force onto the grain bed beneath the wort level and can potentially disrupt the grain bed allowing particles to flow out of the bed into the kettle...right?

I'll buy that... but how significant can this be if it's actually occurring...that's the real question.
Title: Re: Mash Out?
Post by: bluesman on December 18, 2010, 03:00:50 pm
The world is flat where I live.

A real man of genius!   
Title: Re: Mash Out?
Post by: Mikey on December 18, 2010, 04:20:35 pm
The world is flat where I live.

A real man of genius!  

Thank you and I'll try to explain it to you some day.
Title: Re: Mash Out?
Post by: bluesman on December 18, 2010, 04:47:57 pm
The world is flat where I live.

A real man of genius!  

Thank you and I'll try to explain it to you some day.

Your welcome.

No explanation is necessary.