[RC]

In the OP you mentioned you were a batch sparger. Are we still talking about batch sparging here, or continuous sparging? If the latter, then slowing the runoff speed and gaining extra points makes perfect sense. But if the former, it makes no sense--all the wort should be at the same density for a given batch runoff. And so channeling and paths of least resistance are not applicable (or at least, they shouldn't be). Could it be that slowing the wort simply allowed a little extra time for the enzymes to work, and that this was the cause of the point gain? Just curious if overall mash time was considered as possibly the true independent variable here.

[BrewBama]

Well, I am not batch sparging in the traditional sense where strike liquor is added the the MLT, grain is stirred in, rest for x period of time, vorlauf with a pitcher, gravity drain the first run, add the entire sparge liquor, stir, rest for x period of time, vorlauf with a pitcher, and gravity drain the second run.

I add strike liquor to cover the false bottom, add grain to  an otherwise dry MLT, continue to underlet the grain via pump from the BK into the MLT, recirculate with a pump during the mash via RIMS, pump the entire first run from the MLT, gravity drain the entire sparge liquor from the HLT into the MLT, recirculate with a pump via RIMS, and pump the entire second run from the MLT.

I call it ‘batch sparge’ because I empty the MLT of the first run and then add the entire batch of sparge liquor, then empty it again. Maybe it’s more of a hybrid method because of the recirculation via the RIMS.

I’ve been brewing this way for years.  I’ve been routinely getting low to mid 80% mash (aka lauter) efficiency doing it this way and have been very happy with the beer.

But I made a recent change to my MLT setup that negatively affected my normal mash efficiency.  So the research and learning curve ensued.

I believe the channeling around the grain bed was occurring because I was running the pump too fast with this new setup.  Once I slowed the pump down on this last batch I again hit my low 80% mash efficiency.

The only change I made was slowing the pump speed. Mash time remained the same but there could be more happening.


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[RC]

Ah...makes more sense now. This method might be called pseudo batch sparging? If you don't give the mash a good stir when you add the sparge water, and simply start recirculating, then channeling and path-of-least-resistance definitely come into play. Just curious, is there any reason why you can't/don't give the mash a good stir when you add the sparge water, wait a minute or two to reach equilibrium, and then start the recirculation? Stirring the mash would maximize extraction without the need to fiddle with runoff speed. Anyway, thanks for indulging my questions.

[BrewBama]

I could easily do that. I used to stir once the sparge volume was added but I forgot once and didn’t realize any difference so I quit. I do usually gently stir at strike just to ck for dough balls ...but there are never any dough balls with underletting that I’ve ever seen.

[majorvices]

These are commerical-level considerations. Seems unnecessarily complicated for homebrewing. It's like using a backhoe when all you need is a trowel, or even just a spoon. Just curious, what's the goal here? Is this a solution looking for a problem? If it's just playing around, totally cool, to each their own. Again, just curious. Cheers.

I don't disagree but if someone is insisting using a pump and a grant for whatever reason then that would be the way to go. At home I use a batch sparge cooler if I'm not using the BrewZilla.

[ynotbrusum]

On my larger (10 gallon batch) three vessel set up, I use the InfuSSion 20 gallon mash tun, because it has a manometer and I can easily monitor and adjust recirculation issues (differential pressure reflected by fluid height in each tube - one above the false bottom and one below it).  This is a HERMS system, so it runs through a coil in the HLT, which complicates things.  I have butterfly valves at the MLT outlet, at the pump outlet and at the HERMS outlet returning from the HLT to the MLT.  I adjust at the pump outlet and HERMS outlet to maintain a constant flow level in the manometer tubes.  The best flow rate is pretty slow - 2 clicks on the butterfly valves.  All of this is based on trial and error, so I have no idea on actual flow rate.

I do the hybrid batch sparge approach frequently.  On my 5 gallon system, I pretty much BIAB batch sparge and rarely recirc on that one anymore...

[BrewBama]

+1. The manometer would be a more direct approach to monitor differential pressure but that was an impossibility for my setup without major Frankenstein work. That is very unappealing. So, I went with what I think is the next best solution. That is: flow rate. I use a linear flow valve and now a rotameter to precisely control the flow. I can see flow change at a constant valve setting indicating a change in different pressure.

I was lifting and pouring a bazillion degree water into my mash tun for batch sparging and I started to think about how that's really unsafe and messy. So yeah, I insisted on using a pump. The only downside I have experienced since incorporating it into my system is having one more component to clean.

Since I have the pump I might as well recirculate during the mash.  Unnecessary complexity unless you like that kind of thing. I do. As far as I know, most if not all the ‘grain father-like’ all-in-one systems recirculate during the mash with a pump. So there must be a lot of those who appreciate unnecessary complexity.

I guess to eliminate controversy I could lift my grain off the wort instead of pumping the wort off the grain. Or, I could turn off the pump and gravity drain ...but then I’m right back to lifting large volumes of bazillion degree liquid.

.. If you don't give the mash a good stir when you add the sparge water, and simply start recirculating, then channeling and path-of-least-resistance definitely come into play. ...

I think I was getting path of least resistance before sparge, in the main mash. (Edit: Settling of the grainbed due to loss of fluidity leading to preferential flow) I say this because I can use Sean Terril’s Batch Sparge Calculator to know what neighborhood my first runnings should be in. I found I was low ...by a lot. That was an indication that I had a problem. I wasn’t getting the extract from the grain. Slowing the flow during recirculation and lauter seems to correct that problem but admittedly I’ve only brewed one batch since making this change. (Edit: I base this on the theory that the more uniformly the water moves through the grainbed, the more sugar it can extract from the grain. This results in better extraction efficiency.) We’ll see.

...Anyway, thanks for indulging my questions.

I don’t mind the questions. It has caused me to ensure each of the steps in my processes are value-driven. 

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[denny]

+1. The manometer would be a more direct approach to monitor differential pressure but that was an impossibility for my setup without major Frankenstein work. That is very unappealing. So, I went with what I think is the next best solution. That is: flow rate. I use a linear flow valve and now a rotameter to precisely control the flow. I can see flow change at a constant valve setting indicating a change in different pressure.

I was lifting and pouring a bazillion degree water into my mash tun for batch sparging and I started to think about how that's really unsafe and messy. So yeah, I insisted on using a pump. The only downside I have experienced since incorporating it into my system is having one more component to clean.

Since I have the pump I might as well recirculate during the mash.  Unnecessary complexity unless you like that kind of thing. I do. As far as I know, most if not all the ‘grain father-like’ all-in-one systems recirculate during the mash with a pump. So there must be a lot of those who appreciate unnecessary complexity.

I guess to eliminate controversy I could lift my grain off the wort instead of pumping the wort off the grain. Or, I could turn off the pump and gravity drain ...but then I’m right back to lifting large volumes of bazillion degree liquid.

.. If you don't give the mash a good stir when you add the sparge water, and simply start recirculating, then channeling and path-of-least-resistance definitely come into play. ...

I think I was getting path of least resistance before sparge, in the main mash. I say this because I can use Sean Terril’s Batch Sparge Calculator to know what neighborhood my first runnings should be in. I found I was low ...by a lot. That was an indication that I had a problem. I wasn’t getting the extract from the grain. Slowing the flow during recirculation and lauter seems to correct that problem but admittedly I’ve only brewed one batch since making this change. We’ll see.

...Anyway, thanks for indulging my questions.

I don’t mind the questions. It has caused me to ensure each of the steps in my processes are value-driven. 

Sent from my iPad using Tapatalk

Have you checked conversion efficiency?  Your first running could be low because you aren't getting it all out or it could be low due to poor conversion.

[Thirsty_Monk]

+1. The manometer would be a more direct approach to monitor differential pressure but that was an impossibility for my setup without major Frankenstein work. That is very unappealing. So, I went with what I think is the next best solution. That is: flow rate. I use a linear flow valve and now a rotameter to precisely control the flow. I can see flow change at a constant valve setting indicating a change in different pressure.

I was lifting and pouring a bazillion degree water into my mash tun for batch sparging and I started to think about how that's really unsafe and messy. So yeah, I insisted on using a pump. The only downside I have experienced since incorporating it into my system is having one more component to clean.

Since I have the pump I might as well recirculate during the mash.  Unnecessary complexity unless you like that kind of thing. I do. As far as I know, most if not all the ‘grain father-like’ all-in-one systems recirculate during the mash with a pump. So there must be a lot of those who appreciate unnecessary complexity.

I guess to eliminate controversy I could lift my grain off the wort instead of pumping the wort off the grain. Or, I could turn off the pump and gravity drain ...but then I’m right back to lifting large volumes of bazillion degree liquid.

.. If you don't give the mash a good stir when you add the sparge water, and simply start recirculating, then channeling and path-of-least-resistance definitely come into play. ...

I think I was getting path of least resistance before sparge, in the main mash. I say this because I can use Sean Terril’s Batch Sparge Calculator to know what neighborhood my first runnings should be in. I found I was low ...by a lot. That was an indication that I had a problem. I wasn’t getting the extract from the grain. Slowing the flow during recirculation and lauter seems to correct that problem but admittedly I’ve only brewed one batch since making this change. We’ll see.

...Anyway, thanks for indulging my questions.

I don’t mind the questions. It has caused me to ensure each of the steps in my processes are value-driven. 

Sent from my iPad using Tapatalk

Have you checked conversion efficiency?  Your first running could be low because you aren't getting it all out or it could be low due to poor conversion.

If your pH is in the range and mash temperature is in the range, you should achieve full conversion.

Now we can start talking about grain crush and lauter speed

[denny]

+1. The manometer would be a more direct approach to monitor differential pressure but that was an impossibility for my setup without major Frankenstein work. That is very unappealing. So, I went with what I think is the next best solution. That is: flow rate. I use a linear flow valve and now a rotameter to precisely control the flow. I can see flow change at a constant valve setting indicating a change in different pressure.

I was lifting and pouring a bazillion degree water into my mash tun for batch sparging and I started to think about how that's really unsafe and messy. So yeah, I insisted on using a pump. The only downside I have experienced since incorporating it into my system is having one more component to clean.

Since I have the pump I might as well recirculate during the mash.  Unnecessary complexity unless you like that kind of thing. I do. As far as I know, most if not all the ‘grain father-like’ all-in-one systems recirculate during the mash with a pump. So there must be a lot of those who appreciate unnecessary complexity.

I guess to eliminate controversy I could lift my grain off the wort instead of pumping the wort off the grain. Or, I could turn off the pump and gravity drain ...but then I’m right back to lifting large volumes of bazillion degree liquid.

.. If you don't give the mash a good stir when you add the sparge water, and simply start recirculating, then channeling and path-of-least-resistance definitely come into play. ...

I think I was getting path of least resistance before sparge, in the main mash. I say this because I can use Sean Terril’s Batch Sparge Calculator to know what neighborhood my first runnings should be in. I found I was low ...by a lot. That was an indication that I had a problem. I wasn’t getting the extract from the grain. Slowing the flow during recirculation and lauter seems to correct that problem but admittedly I’ve only brewed one batch since making this change. We’ll see.

...Anyway, thanks for indulging my questions.

I don’t mind the questions. It has caused me to ensure each of the steps in my processes are value-driven. 

Sent from my iPad using Tapatalk

Have you checked conversion efficiency?  Your first running could be low because you aren't getting it all out or it could be low due to poor conversion.

If your pH is in the range and mash temperature is in the range, you should achieve full conversion.

Now we can start talking about grain crush and lauter speed

It would be nice to assume full conversi0n, but it isn't always the reality.  http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency#Determining_Conversion_Efficiency

[RC]

I was lifting and pouring a bazillion degree water into my mash tun for batch sparging and I started to think about how that's really unsafe and messy. So yeah, I insisted on using a pump. The only downside I have experienced since incorporating it into my system is having one more component to clean.

Since I have the pump I might as well recirculate during the mash.  Unnecessary complexity unless you like that kind of thing. I do. As far as I know, most if not all the ‘grain father-like’ all-in-one systems recirculate during the mash with a pump. So there must be a lot of those who appreciate unnecessary complexity.

The lifting and pouring of large volumes of scalding hot sparge water can be eliminated by using a pitcher. I use a one-gal heat-safe plastic pitcher to scoop sparge water into the MT one gallon at a time. Easy peasy.

One of the points of recirculating the mash is to keep the enzymes in continuous contact with new substrate. Stirring periodically achieves the same thing. The point of the all-in-ones is simplicity, and recirculating with the built-in pump is more consistent with this than is stirring. So for the all-in-ones, it's necessary complexity. And actually, "complexity" isn't really the case, either.

You may indeed have gotten channeling/path-of-least-resistance in the main mash, but it wouldn't matter since all the liquid is at the same density. It would only matter during the sparge, if you add the sparge water without stirring it in. Point is, with batch sparging you want to have the liquid all be at the same density. That's when extraction stops and you've pulled out all the sugars you can, because equilibrium has been reached. So I return to my main point, which is you should stir the mash after adding sparge water.

[BrewBama]

If your pH is in the range and mash temperature is in the range, you should achieve full conversion.

Now we can start talking about grain crush and lauter speed

That’s the same conclusion I arrived at.

[denny]

If your pH is in the range and mash temperature is in the range, you should achieve full conversion.

Now we can start talking about grain crush and lauter speed

That’s the same conclusion I arrived at.

Me, too.  But I discovered you don't know until you check.  Until then, it's speculation.

[BrewBama]

The lifting and pouring of large volumes of scalding hot sparge water can be eliminated by using a pitcher.

No thx. The point is to underlet and recirculate during the entire mash. I am not doing that with a pitcher.

One of the points of recirculating the mash is to keep the enzymes in continuous contact with new substrate.  ... recirculating with [a] pump is more consistent with this than is stirring.

We agree. Which is one reason I use RIMS.

...but you have given me an idea. I could use a one gal stainless steel milk can to gravity drain the MLT after the mash is complete thereby eliminating the problems Keith pointed out in reply #8 above (edit: correct post was #9). I can use a hose from the MLT valve to fill from the bottom of the milk can. Then manually transfer the sweet wort (gently — without splashing) to the BK ~one gal at a time.

[ynotbrusum]

...but you have given me an idea. I could use a one gal stainless steel milk can to gravity drain the MLT after the mash is complete thereby eliminating the problems Keith pointed out in reply #8 above. I can use a hose from the MLT valve to fill from the bottom of the milk can. Then manually transfer the sweet wort (gently — without splashing) to the BK ~one gal at a time.

By happenstance that is precisely what I do (draining a gallon of wort gently into a 6.5 gallon bucket with a hose running to the bottom of the bucket then swapping in a second bucket and repeating over and over until the full transfer is complete and the batch sparge water is added, stirred, and the same process is repeated).

Cheers!