Pitiful Extraction from Cooler Mash Tun

I've never had a problem with extraction in my years of doing this. Suddenly now my last two mashes have been pitifully weak.

Yesterday's dunkelweizen...

5# dark wheat malt
3.5# Pilsner malt
1# dark Munich malt
0.5# Caramunich II
0.3# Caramel 120
bottled spring water at a 1.5Q/# mash ratio

Mashed for 90min at 152, stirring vigorously at the beginning and middle of the mash. Starch test was clean, batch sparged over the course of an hour to collect 6.5G.

Boiled to 5.5G and 1.039, when the 5G target was 1.053.

What am I doing wrong?

Was anything different with the last two than your previous batches. Do you mill your own grain- if not were the last two grain bills milled by your usual source?

I also batch sparge and I once forgot to drain my tun between first and second runnings and suspect it is the reason I suffered record low efficiency on that batch.

Curious, what is your reasoning behind such a long batch sparge? I typically go 5-10 minutes/ batch and I have had success.

ishkabibble said:

I've never had a problem with extraction in my years of doing this. Suddenly now my last two mashes have been pitifully weak.

Yesterday's dunkelweizen...

5# dark wheat malt
3.5# Pilsner malt
1# dark Munich malt
0.5# Caramunich II
0.3# Caramel 120
bottled spring water at a 1.5Q/# mash ratio

Mashed for 90min at 152, stirring vigorously at the beginning and middle of the mash. Starch test was clean, batch sparged over the course of an hour to collect 6.5G.

Boiled to 5.5G and 1.039, when the 5G target was 1.053.

What am I doing wrong?

Click to expand...

My guess is that it has something to do with the batch sparging. As an other has said this is usually a quick process. You mentioned that it took you 1 hr to do so I am wondering if it is a temperature change issue during the sparge. I myself have never batch sparged so I may be speaking out of turn, but I have read a lot on it.

Can you describe the process you go through when you batch sparge.

Over the years, I've batch sparged anywhere from 10-60min. I've never noticed a difference in extraction from one end of the time spectrum to the other. I let it run long yesterday because it's a high-gravity thing and I was paranoid about getting all of my grain rinsed.

Normally...
I gather my first runnings over the course of 5-15min, add 170F sparge water, stir, settle for 10min, then drain over the course of 5-35min.

Yesterday, I gathered first runnings for 20min, sparged as usual, then drained over 40min.

It's the usual grist from the usual retailer.

I have one of the long Coleman coolers...maybe I need a cylindrical one? (This still doesn't explain my previous spot-on numbers, though.)

Do hydrometers go bad, get outta whack?

The only thing that's changed:

Normally I collect by first and second runnings in a bucket before splitting it into two pots to boil.

Yesterday, I collected the first runnings in one pot, boiled, cooled, and put it into the fermenter.

I collected the second runnings into a second pot, treated it the same, and poured it into the fermenter.

I drew my sample for the gravity test straight off the top...maybe I unintentionally pulled mostly lower-grav second runnings? (But I would think that my pouring through a sieve into a fermenter would mix the two runnings sufficiently.)

I have a 54 qt rectangular Coleman cooler and get good, reproducible results.

The only times I've seen huge swings in efficiency in batch sparging have been a change in milling, or something going wrong with the manifold or hose braid in the mash tun.

If you mill your own grain, double check the gap settings. If you buy your grain pre-milled, consider getting your own mill -- it's nice to think that they don't mess with the crush, but it's unrealistically optimistic.

corax said:

The only times I've seen huge swings in efficiency in batch sparging have been a change in milling, or something going wrong with the manifold or hose braid in the mash tun.

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Can you elaborate on something going wrong with the hose braid? I am trouble shooting efficiency and suspect I need a new braid but as far as I know as long as it filters out the grain it's fine, right?

kako187 said:

Can you elaborate on something going wrong with the hose braid? I am trouble shooting efficiency and suspect I need a new braid but as far as I know as long as it filters out the grain it's fine, right?

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Hose braid version 1.0 was about 18 inches long, and serpentined around the bottom of the cooler. It worked great a few times. but then I must have stirred the mash too vigorously, and the end of the braid came up off the bottom, coming to rest somewhere in the middle of the grain bed. Efficiency went WAY down for that batch. Version 1.1 is only about 4 inches long, and it always stays nicely in place and gives me great efficiency every time.

This underscores the point that for batch sparging, you don't need to drain from more than a single point, and a long braid/screen (or a full manifold) is superfluous at best (and in my case, detrimental).

corax said:

Hose braid version 1.0 was about 18 inches long, and serpentined around the bottom of the cooler. It worked great a few times. but then I must have stirred the mash too vigorously, and the end of the braid came up off the bottom, coming to rest somewhere in the middle of the grain bed. Efficiency went WAY down for that batch. Version 1.1 is only about 4 inches long, and it always stays nicely in place and gives me great efficiency every time.

This underscores the point that for batch sparging, you don't need to drain from more than a single point, and a long braid/screen (or a full manifold) is superfluous at best (and in my case, detrimental).

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ok, that's pretty interesting!

i, too, found my lengthly hose braid up around the mid-mash level rather than on the floor of the cooler.

i can't, however, figure out how a wandering hose would affect efficiency. it's not like there's any liquid left at the end of the lautering.

maybe i'll cut my hose down to 6" or so and hook it up that way. that whopping hose full of holes on all sides never made sense to me as a conduit.

although, i would think a mesh cage over the inlet to the spigot would work best.

Make sure you calibrate your thermometer(s). That was my issue when I experienced a couple bad efficiencies after never having an issue.

The first thing that jumps out at me is that the mash is about 50% wheat. Wheat doesn't have a husk, and it's much smaller to crush than barley malt so if you didn't crush it finer than the usual grains, you may not have crushed the wheat enough. If you didn't get a stuck sparge, and didn't use rice hulls, I would bet that the wheat wasn't crushed enough.

I also think the ultra slow drain in the batch sparge worked against you, as that would give the sugars time to resettle onto the grain. The idea behind batch sparging is to "knock" the sugars into solution and drain while they are still insolution. Letting it go slow gave it plenty of time to channel and with a braid, that would be a huge issue.

^ I felt the wheat + time might be the culprit as well.

ishkabibble- for high gravity beers I have taken the advice to sparge more volume and boil longer- this seems to work for me. Although I haven't had to adjust too much until I start pushing 1.080.

Yeah hydrometers need to be calibrated from time to time using distilled water.

I have successfully maneuvered my braid back to the bottom of the tun by stir-scooping the grain away from where I want the hose to be until it settles there instead of trying to play with the hose directly.

EDIT: I have a square tun- I imagine it's much harder to do this in a round one.

ishkabibble said:

I have one of the long Coleman coolers...maybe I need a cylindrical one? (This still doesn't explain my previous spot-on numbers, though.)

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I theorize that stuck sparges through a braid are less of an issue in a chest cooler as opposed to an upright since the weight of the grain bed is more spread out. I use the 52 qt. coleman extreme and I love it. I am consistently getting good numbers from it. Now that I have my own mill I have hit the 80's.

The more wheat I use, the worse my efficiency is. The wheat malt is smaller and, I find, is much more difficult to crush as well as barley malt. Have you had efficiency issues using this much wheat before?

Yooper said:

The first thing that jumps out at me is that the mash is about 50% wheat. Wheat doesn't have a husk, and it's much smaller to crush than barley malt so if you didn't crush it finer than the usual grains, you may not have crushed the wheat enough. If you didn't get a stuck sparge, and didn't use rice hulls, I would bet that the wheat wasn't crushed enough.

I also think the ultra slow drain in the batch sparge worked against you, as that would give the sugars time to resettle onto the grain. The idea behind batch sparging is to "knock" the sugars into solution and drain while they are still insolution. Letting it go slow gave it plenty of time to channel and with a braid, that would be a huge issue.

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as much as i want to blame my probs on devices and ingredients, i know that most of my issues in life have been operator-errors. i lautered too long, and let the temp drop. that has to be it.

so you really just open up that cooler spigot and let it run full-bore?

FWIW, here's a post I started a while ago on my efficiency issues when using wheat malt. The post includes some real data that show, for me anyway, the correlation between increased wheat in the grist and decreased efficiency.

https://www.homebrewtalk.com/f128/wheat-malt-mash-efficiency-390214/

def agree with Yooper on the long lautering on the batch sparge. I still will vorlauf off the first 1qt at slow speed watching the clarity, kick it up, slowly pour back in the 2 qts, drain 2 more qts mostly wide open as long as it keeps draining clear. Takes me about 18 min to drain my first runnings and about 12-15 min for my second runnings. That grain bed should still be around 150-160* after you've drained. Atleast I've found that consistancy has helped retain my avg 74-76% effeciency.

Shorter braids or circular braids def help, but it's mostly because that braid will stay down, if it's too long the braid just kinks, and I've learned just dial in whatcha got within controllable variables and don't change a method if it works. I've personally had the best batch sparges at 25 minutes, while stirring every 5 minutes and one last time a minute or 2 before starting my draining. Like Yooper and others have said, you don't want those sugars that are suspended to restick back to the grain. I've shot myself in the foot plenty of times, until I stopped trying to do different things.

"I've personally had the best batch sparges at 25 minutes, while stirring every 5 minutes and one last time a minute or 2 before starting my draining."

wowzers. i've rarely ever let my sparge water hang out longer than a few minutes before draining, nor have i ever stirred it. i thought establishing a grain bed was paramount. i'll try it yer way on my next batch.

but i can't imagine a wide-open drain still taking a combined half-hour to complete. you have it open all the way? this is 5G?

ishkabibble said:

Yesterday, I collected the first runnings in one pot, boiled, cooled, and put it into the fermenter.

I collected the second runnings into a second pot, treated it the same, and poured it into the fermenter.

I drew my sample for the gravity test straight off the top...maybe I unintentionally pulled mostly lower-grav second runnings? (But I would think that my pouring through a sieve into a fermenter would mix the two runnings sufficiently.)

Click to expand...

I'm not discounting the explanations given by others, but this jumped out at me as the most obvious culprit.

This would be the same problem that causes so many newbie extract brewers to think their OG was off the mark. It takes time for the two different liquids to combine thoroughly. Unless you mixed them really well and waited a while, you probably just didn't get an accurate reading.

signpost said:

I'm not discounting the explanations given by others, but this jumped out at me as the most obvious culprit.

This would be the same problem that causes so many newbie extract brewers to think their OG was off the mark. It takes time for the two different liquids to combine thoroughly. Unless you mixed them really well and waited a while, you probably just didn't get an accurate reading.

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I somehow missed this quirk of procedure in my initial read-through and, indeed, this may explain a lower-than-expected OG reading. I do the exact same process - collect and boil 1st and 2nd runnings separately and combine them in the fermenter. I always take pre- and post- gravity readings of both runnings separately because of this issue. Since I know my volumes, calculating an OG for the combined runnings is easy and I don't have to worry with dealing with a stratified wort in the fermenter.

Do you have any pre-boil readings? Unfortunately, without those it will be difficult/impossible to know if your gravity measurement was true or not...since it COULD be low because of all the aforementioned reasons (high percent o wheat malt, channeling, too long a lauter).

i don't have a pre-boil grav, no. was too anxious to get the first pot boiling.

as my original post said, yeah, i was suspicious of stratification, but i poured in the second runnings from such a great height i can't see how they weren't mixed. i was going to drop my hydrometer directly into the cooled/combined wort, but there was such a mountain of starsan foam on top i couldn't see anything so i just grabbed a sample from the top with a baster.

this is my usual method anyhow, and i can't say my results have ever been so low.

your data shows clearly how wheat impacts efficiency, but considering my previous brew--an all-barley malt ipa--was also low efficiency, i suspect my technique is to blame.

after all these years i've lost my efficiency mojo.

and as for lauter-rate, there's no shortage of contradictory information on the interwebs. so to separate out the rest of the chaff online, my takeaway message here is: a single-rest infusion in a long cooler with a wire-mesh hose screen needs to be drained as fast as possible?

I originally missed the split batch trick as well, and agree that is a likely culprit.

Regarding lautering time, while I always drain ASAP, I really doubt that is going to hugely affect efficiency. Sugars are highly soluble -- there is no way they are going to come out of solution, or be preferentially reabsorbed by the grain once they are in equilibrium with the mash or sparge water.

ishkabibble said:

and as for lauter-rate, there's no shortage of contradictory information on the interwebs. so to separate out the rest of the chaff online, my takeaway message here is: a single-rest infusion in a long cooler with a wire-mesh hose screen needs to be drained as fast as possible?

Click to expand...

No, not really. But to drain so slowly is probably a problem as the sugars would settle back into the grain.

One thing that struck me is the lack of stirring in the sparge water. I'm not exactly sure if that's what you said, but it sounded like that.

When you batch sparge, you simply vorlauf the mash and drain the runnings. Then, add your sparge water and stir it in like it owes you money. Stir it like it's your job. Then, vorlauf and drain. There is no reason to slowly drain, and draining quickly is the norm. But the thorough stirring is crucial before vorlaufing and draining. That's the way batch sparging works. With a braid, draining slowly may mean channelling in the grainbed. You don't want that- you want to knock the sugars into the liquid and drain it out before too long.

Yooper said:

No, not really. But to drain so slowly is probably a problem as the sugars would settle back into the grain.

One thing that struck me is the lack of stirring in the sparge water. I'm not exactly sure if that's what you said, but it sounded like that.

When you batch sparge, you simply vorlauf the mash and drain the runnings. Then, add your sparge water and stir it in like it owes you money. Stir it like it's your job. Then, vorlauf and drain. There is no reason to slowly drain, and draining quickly is the norm. But the thorough stirring is crucial before vorlaufing and draining. That's the way batch sparging works. With a braid, draining slowly may mean channelling in the grainbed. You don't want that- you want to knock the sugars into the liquid and drain it out before too long.

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my fellow michigander strikes again with solid methodology! i followed that very technique this saturday and banged out a 1060 porter that was only slated to net 1052. and yes, i've always been a stirrer, but i've never stirred it as though it were indebted to me.

i would consider this thread solved.

many, many thanks!

I don't want to threadjack, but it seems like the OPs issue is resolved...so, I have a related question.

I batch sparge and so do not lauter particularly slowly (having listened to Denny Cohn on the subject several times), but I've always been hesitant to lauter as quickly as possible. Is it recommended that I just open the valve up completely and not worry AT ALL about how quickly it drains?

ishkabibble said:

my fellow michigander strikes again with solid methodology! i followed that very technique this saturday and banged out a 1060 porter that was only slated to net 1052. and yes, i've always been a stirrer, but i've never stirred it as though it were indebted to me.

i would consider this thread solved.

many, many thanks!

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Worked for me as well. I have gotten solid advice from Yooper at least once or twice on my own threads and probably about a dozen plus on other peoples' threads.... sort of like this situation.

May your porter be hearty!