Maximizing Efficiency when Batch Sparging

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FlyGuy

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The question of how to improve efficiency often comes up, and I sometimes get PMs asking advice. Rather than repeat the same information, I thought I would write my thoughts down in this thread so that it could be referenced in the future.

Efficiency issues are often difficult to diagnose -- it is just something you have to figure out through trial and error (for this reason, always take detailed notes of your recipe and process each and every brew!). Here are some ideas to think about, in approximate order of importance:

• Your crush will have a big impact on your mash efficiency (although some debate this point). Regardless, the biggest gains in efficiency that users tend to report are when they improve their crush (e.g., buy their own mill). If your LHBS is crushing your grain for you, consider that most shops will set their crush so that their customers get between 60 and 70% efficiency. They may claim it is to help brewers avoid stuck mashes, but conveniently, it also helps them to sell more grain!

• The ratio of sparge water to mash water is a critical factor determining efficiency when batch sparging. Some brewers forget that high gravity recipes will have proportionally less sparge water (because so much water was needed to mash the large volume of grain), and therefore, they will also have less water to dissolve extracted sugars resulting in lower extract efficiency. This seems to be particularly true for those who batch sparge. The two common solutions are either to add extra sparge water and lengthen the boil to compensate, or to simply plan for the reduction in efficiency in the recipe.

• It is very important to hit your mash temperature and hold it for the length of the mash to get full conversion. A common problem is that people miss their temp (e.g., didn’t pre-heat their mash tun or their thermometer is out of calibration), and their extract efficiency suffers because the enzymes in the mash were operating in less-than-optimal conditions.

• Wort losses in the system (e.g., incomplete draining of mash tun or other dead spaces in gear like counter-flow chillers, etc.) can take a big toll on your brewhouse efficiency. These are sometimes overlooked because people are too focused on their extract efficiency rather than their overall (brewhouse) efficiency.

• It is hard to accurately compute efficiency if you don't have precise measurements of your water/wort. Sometimes people think they are getting poor efficiency in their system, but it just turns out they are over-estimating the amount of water used in a brew or under-estimating the amount of wort collected.

• When mixing your grain with water at the beginning of the mash, it is CRITICAL that everything is mixed completely to avoid doughballs or dry lumps of grain. If the grain is not sufficiently wetted, it won't convert, robbing you of efficiency points.

• When batch sparging, the temperature of the mash-out and/or sparge water influence your extract efficiency. You want to make sure that either your mash-out infusion or your first batch sparge addition are hot enough to raise the grist to as close to 170 F as possible. This allows more sugar to be dissolved and reduces viscosity to facilitate easier lautering, both of which will improve your efficiency.

• Also when batch sparging, it is critical that you stir the mash fully after adding mash-out water and/or the first sparge water addition. It may help to stir before each subsequent sparge water addition, but that depends on your system.

• pH of the mash is usually not a problem for most brewers, but some water sources can be problematic. If so, the use of a pH stabilizer, like Five Star 5.2 buffer can help achieve an optimal mash pH, and may result in a 5 - 10% increase in efficiency.
 
Nice write-up. I'm currently trying to validate some more of the points about extraction efficiency. In particular mash thickness, crush, mash-out and time. But that actually applies to fly and batch sparging.

Here is some info on what factors affect the lauter efficiency part of the brewhouse efficiency when batch sparging.

Kai
 
I would be curious to know from those of you who track their grind setting on their mills...what is your prefered setting. I don't own a mill, but my brew supply store has an industrial grade mill with a caliper on it. I noticed the other day when I was grinding out a grain bill that the setting was on.032" I asked one of the emplyees who has worked there a long time and he said that was their "standard setting". Not for nutin', but I have been getting low efficiencies (60%) for over a year now (I have my brew system calibrated down to the last ounce of fluid) and have been scratching my head ever since. When I changed the settings to grind at .020", the guy freaked out and pushed me to pick up some rice hulls to prevent a stuck sparge, which I did just in case. I am starting to wonder if the .032" setting was a bit too course and may be the part of the problem.

Thoughts?
 
32 mil (0.8 mm) is a fairly decent setting and you should not be getting only 60% efficiency with that. 20 mil (0.5 mm) is to fine in my opinion. I crush mine between 0.6 and 0.7 mm (24-26 mil) which gives me the 100% conversion and subsequently 85+% brewhouse efficiency that I’m looking for.

Inthekeg, if you are interested in going a systematic route of troubleshooting and fixing your brewhouse efficiency, give these articles some reading:

* Troubleshooting Efficiency
* Understanding Efficiency

Kai
 
Thaks for your input Kaiser. I am doing an all grain Hefe tomorrow morning early. I record everything, everytime I brew. Maybe I'll posy here and get some comments that help narrow it down. The trouble has been the cause is somewhat elusive. My PH is always right on, I don't rush my mash-out, I iodine test for conversion, etc, etc.

Part of the problem may be that I may be short changing myself on the sparge side. I am going to explore the possibility that I might still have plenty of residual sugar left in the Mash Tun left AFTER the point I have hit my volume. This is the only aspect of my brewing that is, as of yet, unexplored as a potential source of the problem. Still, I just can't believe that I have more that 1.015 when I shut it down.
 
Hi guys,
first post on this site. As I type, my first all-grain is boiling away on my gas stove. I was a little worried, however, that my SG after two runnings through my newly created MLT (batch sparge) was 1.043. Too inefficient? Here's my grain bill for "The Pale" AKA "El Pale Alerino if you're not into the whole brevity thing":
9 pds 2-row
1 crystal 15
1/2 carapils
1/4 munich

Mashed in w/ 3gal.@ 156F. This didn't drop for the 70 minutes of mash time. Then I added 1 gal @180 to fill up my 5 gal cooler. First runnings took just over 30 minutes. 2nd runnings w/ 3 gal. water @ 180. Lasted about 20 minutes.
Is all of this within normal parameters?
Thanks in advance,
Ike

-it's a Lebowski kind of Sunday
 
That's a might slow runoff for batch sparging! It takes me 15 min. from the time I start my mash runoff until the end of my sparge runoff. Buit I doubt that had anything to do with your efficiency. Grain crush is always the first place I look to increase efficiency.
 
Grain crush is always the first place I look to increase efficiency.

And decrease of run-off rate. I have had 45 – 60 min batch sparging times. Especially when using a lot of wheat malt. But I prefer that over the addition of rice hulls.

Kai
 
So, if I get this right, it's better to have a quicker run-off than what I did?
Also, my run-off was between 6.5-7 gallons, but a LOT seemed to boil off, as I only ended up with about 4 gal in the carboy! Tasted great though. Would it be advantageous to do a third running and just boil it down in two kettles until it all fits into the main one (I have an 8 and a 4 gal)?

My grind was whatever MoreBeer had set when I cruised by last month. Not sure what it was. (as an aside, I LOVE going in there...like a candy store. The wife won't go with me again...:))

I'll read a little more up on my Charlie before brewing the next one this weekend (an all-grain Porter kit from MoreBeer).
 
Boil off is a very personal thing depending on your boil vigor. I evap out about 1.5 gallons per hour of boil time. Don't worry about your runoff speed with batch sparging. If it will run fast, let it. If not, your crush is either too fine or you have a lot of wheat in the bill. In anycase, the only problem with a really long drawn out runoff is heat loss. Did you have a hose on the output of the MLT or is it just cascading out of the ball valve?
 
No, I had a hose from the MLT to the bottom of the brew kettle/collection tank. I did, however, only open the ball valve about half way. Is it relatively standard practice to just "let er rip" or is there a gray area of finesse that I have yet to discover? As for the boil rate, I suppose I let it go more or less rigorously, though there were no inadvertent boil-overs. I've read that the boil rate can affect protein coagulation, but need to do some more research to make use of this.
Heat loss didn't really seem to be an issue.
 
Even in batch sparging you may need to restrict the flow in order to prevent a stuck sparge. If the "natural" flow rate is to slow b/c of poor husk quality and/or lots of flour the grain bed can still set itself if to fast of a flow is forced. I used to be able to let it "rip", but that was when I bought the grain crushed and got only 75% efficiency. Now I mill finer but need to watch the flow rate.

You'll have to find the sweet spot yourself.

WRT to boil rate, keep it between 8 and 15% per hour. To much can actually hurt the beer as the thermal loading on the wort gets to high.

Kai
 
ich bin fuer den Rat allerdings sehr bedanklich, Herr "Kai". Ich habe Ihre Threads in den letzten Wochen schon ziemlich hilfreich gefunden!

Rock on like a Skorpion:rockin:
 
So, if I get this right, it's better to have a quicker run-off than what I did?
Also, my run-off was between 6.5-7 gallons, but a LOT seemed to boil off, as I only ended up with about 4 gal in the carboy! Tasted great though. Would it be advantageous to do a third running and just boil it down in two kettles until it all fits into the main one (I have an 8 and a 4 gal)?

My grind was whatever MoreBeer had set when I cruised by last month. Not sure what it was. (as an aside, I LOVE going in there...like a candy store. The wife won't go with me again...:))

I'll read a little more up on my Charlie before brewing the next one this weekend (an all-grain Porter kit from MoreBeer).

A faster runoff is not necessarily better, but possible. And don't read Charlie to get info on batch sparging! I start my runoff slowly until the grain bed is set (a minute or 2) then open it up and let it rip. See dennybrew for details. The MoreBeer crush is likely the source of your low efficiency.
 
Even in batch sparging you may need to restrict the flow in order to prevent a stuck sparge. If the "natural" flow rate is to slow b/c of poor husk quality and/or lots of flour the grain bed can still set itself if to fast of a flow is forced. I used to be able to let it "rip", but that was when I bought the grain crushed and got only 75% efficiency. Now I mill finer but need to watch the flow rate.

You'll have to find the sweet spot yourself.

WRT to boil rate, keep it between 8 and 15% per hour. To much can actually hurt the beer as the thermal loading on the wort gets to high.

Kai

We've likley discussed this before, but what type of lautering system do you use? I crush VERY fine, but have never had a stuck runoff using hose braid.
 
HaHa it's funny to see Denny as a "junior" when he is anything but!

I tried retarding the flow in my last batch and it seemed like my first run-off was a little more steady and somewhat shorter. I usually just set the grain-bed and let it rip as per Denny. The second run I opened it up and it actually slowed down some, which is unusual for a second run IME. Normally, it goes a little quicker and easier than the first run.

I might experiment with it a little more but I have a brand new tun to play with, and I haven't done an initial gravity read for the last several batches. Once I get it dialed in I don't worry much about working the efficiency if I get consistent results. I'll see how this new tun does on Friday.

I think getting the mash temp up to around 168F is critical for maximizing the efficiency when sparging- especially when going to a fine grist.

I've been wondering where the fine line is when trying to eke out the last percentage points. In addition to those valuable sugars I suspect that over-sparging can have a negative effect on the flavor of the wort. Maybe an unacceptable level of graininess or astringency? Or possibly a muddying up of the flavors? WAG since I don't think I've ever reached that point.
 
A faster runoff is not necessarily better, but possible. And don't read Charlie to get info on batch sparging! I start my runoff slowly until the grain bed is set (a minute or 2) then open it up and let it rip. See dennybrew for details. The MoreBeer crush is likely the source of your low efficiency.

Thanks for your link Denny. I think I'll try sparging a little quicker this weekend with my first AG porter and perhaps add a little more sparge H2O as well. Though, according to your example on your site (10pd grain, 7gal pre boil wort), I wasn't too far below my target volume.
My MLT, btw, is the Home Depot "special" described in the Brew Wiki. -5 gal circular cooler w/ steel braid.
 
Yes, definitely. In fly sparging, you are using fresh, hot water to gently 'rinse' the sugars out of the grainbed. If you drain too quickly, the water passes over the grain without having the chance to fully dissolve any remaining sugars.

In batch sparging, we aren't rinsing. You just add your batch of sparge water, stir it up to get the sugars in solution, then drain it off. Assuming you don't get a stuck sparge, draining it slow removes just as much sugar as draining it fast.
 
We've likley discussed this before, but what type of lautering system do you use? I crush VERY fine, but have never had a stuck runoff using hose braid.

I ‘m using a cooler with a copper manifold that has slots and holes:

2249-manifold.jpg


I’m generally crushing with a mill set to 0.65 mm (26 mil) and I have gone as low as 0.55 mm (22 mil). But I backed off as 26 mil already allows me to convert all starches in the mash. But I can’t open the valve fully w/o getting a serious reduction in flow rate even with the malt conditioning that I do to preserve more of the husks.

My last 2 beers have been wheat beers, so they were naturally slow running anyway. I’d have to check my notes on the lauter times I get with all barley beers.

b/c I’m usually doing other tasks/chores in parallel, I’m not to worried about a slow lauter but I have been wondering myself why you seem to be getting much faster run-off. Maybe it’s the braid, which has much more small holes, than my manifold, which has less but larger holes. Holes, that might be big enough for grain bits to get stuck in them.

radtek,

I caution you to increase your efficiency by more sparging. In my believe the most common cause for low efficiency is low conversion efficiency. I.e. only a part of the starch in the mash is actually converted. The rest is still tucked away in the grits. This is the part of the efficiency that changes when you change your crush. And you should not compensate for that by trying to rinse out more sugars by using more water as the retrieved wort quality declines with lower gravity run-offs. Instead you should fix your conversion efficiency (finer crush, more optimal pH, thinner mash, longer mash time). This will allow you to start lautering with a higher gravity wort as more sugars are now dissolved in your mash and the gravity of the runnings will not drop as low as they would for a low conversion efficiency for the same amount of sugars collected in the kettle.

Here is an example. You can get 70% efficiency by allowing all starch to be converted and lauter with 70% efficiency. For batch sparging this is no-sparge efficiency for average beers. And no-sparge is known to produce a high quality wort. Or you may convert only ¾ of the starches in the mash (75% conversion efficiency). But now you need to lauter much more efficiently to get 93% of the converted sugars out of the MLT into the kettle. To get this good of a lauter efficiency you need to fly sparge or use multiple batch sparges and in both cases you may need more water. This could lead to oversparging and lower quality wort.

I have written this before, but I wanted to bring this up again as 70% for one brewer may not result in the same quality wort as it does for another brewer. Especially since Jamil has been saying that 70% is about perfect for him.

Kai
 
Here is an example. You can get 70% efficiency by allowing all starch to be converted and lauter with 70% efficiency. For batch sparging this is no-sparge efficiency for average beers. And no-sparge is known to produce a high quality wort. Or you may convert only ¾ of the starches in the mash (75% conversion efficiency). But now you need to lauter much more efficiently to get 93% of the converted sugars out of the MLT into the kettle. To get this good of a lauter efficiency you need to fly sparge or use multiple batch sparges and in both cases you may need more water. This could lead to oversparging and lower quality wort.

I have written this before, but I wanted to bring this up again as 70% for one brewer may not result in the same quality wort as it does for another brewer. Especially since Jamil has been saying that 70% is about perfect for him.
Kaiser, I think this is an exceptionally well-made point, and one that is often overlooked by many homebrewers.
 
What type of malt mill do you have? Also I have a barely crusher and it is on the factory setting of .039 inches. Your mill is set much closer then mine, so I am wondering if i change my mill setting to i need to be exact in my measurement or just make the mills closer.
 
There probably is no 'correct' setting for gap on a mill. You need to experiment with your crush to find what works best on your system. If you are trying to improve your efficiency by milling finer, just keep incrementally crushing finer and finer with each successive batch until you reach the point where you are getting a stuck sparge or you think the fine crush might be hurting the quality of your wort (e.g., shredding husks if using a Corona mill, which is manifesting itself in astringencies in the finished beer). At that point, just back off and make note of the setting (in case you have to re-adjust it down the road).
 
Maybe it’s the braid, which has much more small holes, than my manifold, which has less but larger holes. Holes, that might be big enough for grain bits to get stuck in them.

That has been my observation when comparing manifolds to braids.
 
Kaiser, I think this is an exceptionally well-made point, and one that is often overlooked by many homebrewers.

That was the driving point behind the two articles that I wrote about efficiency: to raise awareness that there are 2 major processes at work. Which are both mostly independent and which can even be measured as that.

One of the problems is that many use an old style mashing technique and expect modern day brewhouse efficiencies. Don’t get me wrong there is nothing bad about using old techniques. But single infusion mashing with about 1.25 qt/lb and a coarsely milled grist w/ batch sparging was never expected to produce efficiencies in the 90s. It’s what old Britsh ale breweries have used and some of them probably still use. To get into the 90s you need to use more modern techniques, which may not be the right choice for a traditional English ale but work for most modern beers. And that is a more tightly milled girst and/or more intense mashing (e.g. agitated mash) to allow better access to the stach. I’m also convinced that a thinner mash (1.5-2 qts/lb) does better. Recently I read that high sugar concentrations can raise the gelatinization temp of starch, i.e. make it harder for the mash to convert the last bit of starch.

Kai
 
I have my Barley Crusher closed as far as it can go- about 0.015". Beer and efficiency are fine.

I boil off about 2.5-3 gallons in a typical 90 minute boil. So I'm getting about 8 gallons total out of the tun for a 5 gallon batch by compensation.

Would I be better off using less sparge water and just topping up the kettle pre-boil? If it would improve my brew I'll certainly try this.
 
Would I be better off using less sparge water and just topping up the kettle pre-boil? If it would improve my brew I'll certainly try this.


Why not boil less intensely. 3 gal lost on a 8 gal preboil is about 25%/hr and a little high IMO. You can save yourself some propane in the process.

As for shredding the husks and astringency, I’m not convinced that there is such a strong correlation as one might think. Some breweries use a mash filter to separate wort and grain. For such a set-up the grist is completely milled to flour (husks and endosperm) and the wort is then pressed from the mash though a filter cloth. I doubt that the beers will show strong astringency.

Kai
 
The situation: 2nd AG brew yesterday. Lower OG than expected. Same problem as 1st AG brew from last weekend (discussed in this thread).
The question: Is my technique simply off or, as suggested with regards to the last brew, is the MoreBeer grind just too coarse? ...or both?
Porter
Grain bill:
8* 2-row
1* Munich
1*Crystal 40L
8oz Carapils
8oz Black Patent
4oz Chocolate
(MLT: 5 gal batch sparger w/ ss braid as per FlyGuy's instructions)
Strike water 3.25 gal. @170
Mash temp dropped from 158 to 156 in 60 min. Stirred twice.
Mash out with 2 qts Vorlauf - took 15 min.
1st sparge 2.75 gal w/Vorlauf, let set 5 min -took under 10 min
2nd sparge 2.25 gal w/Vorlauf, let set 5 min - under 10 min

OG 1.043 (measured after the boil and cooling wort to 85F)

I gathered a good 7 gal of wort that eventually translated to good 5.5 gal in the carboy (much better than the last brew). HOWEVER, the same low-OG problem still came up. This recipe is actually the porter kit from MoreBeer, with an estimated OG of 1.056 (based on 75% efficiency). Clearly I'm not achieving this... but why? hmm
 
1st sparge 2.75 gal w/Vorlauf, let set 5 min -took under 10 min
2nd sparge 2.25 gal w/Vorlauf, let set 5 min - under 10 min

what's your sparge temp? What temp did your grain bed get up to during the sparge?

Did you temp correct your OG? at 85*, you calibrated OG (60*) is ~ pts higher
 
sparge temps were 180 and 181. I tried to get the grain bed up to around 170. This is the hot break(stopping enzyme conversion), correct?

I corrected the hydrometer reading. It was 1.040@85F= OG 1.043

The wort tasted great. It'll just have to be a sessions porter, I guess.
 
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