I thought I understood efficiency...

kh54s10 · May 15, 2015

I have been hitting my numbers pretty consistently. I use a corona mill and have Beersmith set for 68% efficiency. I am usually within a point or two of target.

Today I did a wheat.

4 lbs white wheat malt
3 lbs Rahr 2 row
2 lbs Munich light
Orange peel
.75 oz coriander.

Beersmith says I got 72% mash efficiency but the estimated OG was 1.045 and I got only 1.031.

I am not worried as I was looking for a light summer ale. Just wondering why I got relatively good mash efficiency #'s and low OG?

masskrug · May 15, 2015

68% is pretty forgiving. I'm guessing the wheat threw it off. What temp did you mash? Ratio? WTH is Munich light? Light color?

kh54s10 · May 15, 2015

masskrug said:
68% is pretty forgiving. I'm guessing the wheat threw it off. What temp did you mash? Ratio? WTH is Munich light? Light color?

Mash temperature 148 degrees. Within 1 degree at start and 144 at 75 minutes.

Munich light? Weyermann Munich 1 I assume. The package/order was Light Munich. I don't remember where I bought it. 5.1 to 7.0 Lovibond on the Weyermann site.

IDK, I have used wheat in the past and the numbers were closer.

dragonfire540 · May 16, 2015

Rice hulls. You may not have enough husks in there with all that wheat try adding hulls to get good flow and make sure you keep your sparge rate slow to get best extraction
I had similar issue till I started adding hulls and making my process consistent
Also make sure you know your volumes As efficiency calculations are only as good as your volumes just slight error in pre-boil volume will throw you off

ajdelange · May 16, 2015

kh54s10 said:
I have been hitting my numbers pretty consistently. I use a corona mill and have Beersmith set for 68% efficiency. I am usually within a point or two of target.

Today I did a wheat.

4 lbs white wheat malt
3 lbs Rahr 2 row
2 lbs Munich light
Orange peel
.75 oz coriander.

Beersmith says I got 72% mash efficiency but the estimated OG was 1.045 and I got only 1.031.

I am not worried as I was looking for a light summer ale. Just wondering why I got relatively good mash efficiency #'s and low OG?

You used 9 lbs of grain. You don't say how much wort you prepared but assuming it was 5 gallons that would weigh

5*8.34*1.031 = 42.9927 lbs

1.031 SG is 7.8 Plato so you got 42.9927*7.8/100 = 3.35 lbs of extract. That, divided by the weight of the grain you used gives the efficiency.

100*(42.9927*7.8/100)/9 = 37.3%.

This is not, indeed, very good. Most home brewers attain something in the 60's. At 60%, for example, you'd have 5.4 pounds of extract in 5 gal of wort corresponding to 1.050 SG.

stpug · May 16, 2015

kh54s10 said:
I have been hitting my numbers pretty consistently. I use a corona mill and have Beersmith set for 68% efficiency. I am usually within a point or two of target.

Today I did a wheat.

4 lbs white wheat malt
3 lbs Rahr 2 row
2 lbs Munich light
Orange peel
.75 oz coriander.

Beersmith says I got 72% mash efficiency but the estimated OG was 1.045 and I got only 1.031.

I am not worried as I was looking for a light summer ale. Just wondering why I got relatively good mash efficiency #'s and low OG?

9 lbs * 36 points per pound = 324 points at 100% efficiency
324 points / 5 gallons = 64.8 points/gallon at 100% efficiency
31 points achieved / 64.8 points possible = ~48% brewhouse efficiency

Not quite the same picture that AJ illustrated but still pretty poor efficiency. You definitely need to look into why you're missing out on 1/3 of the potential sugars from your grain because that's pretty significant.

On a different note: You say beersmith is set for 68% efficiency (this is usually brewhouse efficiency people look at in beersmith), and yet you report that beersmith reports you got 72% mash efficiency. Comparing the two is not overly useful with the exception that your brewhouse efficiency should never be higher than your mash efficiency, otherwise it's useless. BTW, 72% mash efficiency is also pretty poor, generally speaking. You should be able to get higher number from both efficiencies with some adjustments to your crush/process/system.

Now, give us some specifics about your system. The more information the better. MLT deadspace. How much wort you leave behind in your brew kettle. How much water you use during your brewing process and how much wort you get back out. Where you get your grain. How it gets crushed. A picture of the crush can sometimes be helpful. Etc. Anything else you can think of that I'm forgetting right now

Gavin C · May 16, 2015

Mash efficiency this low would point to a procedural error. Most likely a poor crush which was made even worse by the use of the smaller wheat kernels.

If you want to try to pin point where there may be room for improvement it may be worth measuring

conversion efficiency. How much sugars are in the mash tun after the mash/theoretical maximum sugars available (TMSA) You need to know the volume of water transferred into the mash tun and the gravity prior to lautering
Mash efficiency: How much sugars have been removed from the mash/TMSA. You need a preboil volume and gravity

If 1 is low (90+ percent is readily achievable with this grain bill) it points to either a poor crush or inaccurate temperature reading or non-optimal mash pH.

If 1 is good and 2 is low it points to an inadequate lautering process.

The brewhouse efficiency will of course be a bit lower as you lose some volumes to trub, hoses, plate chiller, hop absorption etc. Aside from the perceived bragging rights that many seem to equate the quest for high efficiency with, the numbers themselves can help highlight errors in the process. Crush, pH, sparging methods etc. There are lots of variables but each number will nail down the area that can be improved.

Better efficiency through refinement of the process leads to consistency as the pleasant byproduct. Consistency in brewing is something few could argue against. Many will not care one iota, but by the nature of the post I'm guessing you are not in that category.

I hope I have not confused things further. I am certainly no expert but am a bit of a fan of the number crunching game in brewing. A welcome outlet for my inner geek.

Note. For accuracy make sure the gravity is measured at the correct sample temp. I'm sure this is something you are already doing but if you are trying to nail down a system flaw it's very important to be as accurate as possible with both volume and gravity measures.

Easy Volume measures

[*]Correct Gravity Readings

kh54s10 · May 16, 2015

OK, I use a corona mill, I ran it through twice. Crush was almost flower...
I have a 3 tier gravity system. HLT is a 10 gallon pot up top, MLT is a 10 gallon Rubbermaid cooler w/braid. BK is a 10 gallon kettle.
I did a batch sparge. I usually do a little more than half needed to get to preboil, then a second sparge to preboil amount. This time I did a single sparge. There is almost nothing left in the tun when drained.
I used a couple hand fulls of rice hulls and had no problems draining.
I used a refractometer for the gravity measurements. It is the automatic temperature kind. I also waited long enough that the sample would have cooled.

I have made wheat beers before and had much closer to predicted results.

I have to look at the types of efficiency measurements more. But I am usually within a couple points OG this was one of the farthest off I have had.
Good news it that I should be able to drink a lot of it at one sitting.

I don't think I made any measurement mistakes or left anything out. I use a thermapen and think it is spot on. Mash temp started good, dropped about as usual.

Gavin C · May 16, 2015

That's a puzzler for sure.

Were the rice hulls presoaked. If not then they will soak up some of the sweet wort reducing the mash efficiency. I don't think that alone would account for your numbers.

A Thermapen for temp readings mean you can probably discount any errors there. You can always double check its calibration in a glass of crushed ice/water mix to be sure.

An overly fine crush may have led to some dough balls in a thick mash reducing the conversion and mash efficiencies.

A braid. I know many swear by them. Likewise many posters deride them as ineffective and promoting channelling. Something to look at maybe.

Just some thoughts. I'm not a three vessel brewer so I don't speak with any level of practical knowledge I'm afraid. Many of these points may be redundant or way off base.

spenghali · May 17, 2015

When did you take your sample for gravity and where was it pulled from? Your wort might not have been homogeneous...

ajdelange · May 17, 2015

kh54s10 said:
I used a refractometer for the gravity measurements. It is the automatic temperature kind. I also waited long enough that the sample would have cooled.

That may very well be your problem. Refractometers, especially ATC equipped ones if the temperature of the sample isn't carefully controlled, can't be relied on for gravity measurement. They are often quite close but on occasion can be off by a couple of Bx. I grant you, 3 Bx is quite a lot.

Please understand that I am not saying that use of refractometer is your problem. Just that it could be. Perhaps the wort was indeed of normal gravity.

IslandLizard · May 17, 2015

Gavin C said:
[...] An overly fine crush may have led to some dough balls in a thick mash reducing the conversion and mash efficiencies. [...]

Although that's true, if you didn't change anything on the milling, chances are that your wheat wasn't crushed well at all. Wheat kernels are much smaller and harder than barley. A larger percentage may have passed through whole. If you still can, check your spent grains for large grain bits.

Although rice hulls will soak up some wort, it is quite minimal, maybe an ounce or two.

kh54s10 · May 17, 2015

Gavin C said:
That's a puzzler for sure.

Were the rice hulls presoaked. If not then they will soak up some of the sweet wort reducing the mash efficiency. I don't think that alone would account for your numbers.

I did not soak the rice hulls and never have.

A Thermapen for temp readings mean you can probably discount any errors there. You can always double check its calibration in a glass of crushed ice/water mix to be sure.

I haven't checked it recently but have in the past, it was accurate.

An overly fine crush may have led to some dough balls in a thick mash reducing the conversion and mash efficiencies.

There were no dough balls. Because of the wheat I checked this carefully.

A braid. I know many swear by them. Likewise many posters deride them as ineffective and promoting channelling. Something to look at maybe.

Channeling should not be a problem since I batch sparge.

Just some thoughts. I'm not a three vessel brewer so I don't speak with any level of practical knowledge I'm afraid. Many of these points may be redundant or way off base.

spenghali said:
When did you take your sample for gravity and where was it pulled from? Your wort might not have been homogeneous...

I took the measurement, it was low so I stirred the wort well and still got the low numbers.

ajdelange said:
That may very well be your problem. Refractometers, especially ATC equipped ones if the temperature of the sample isn't carefully controlled, can't be relied on for gravity measurement. They are often quite close but on occasion can be of by a couple of Bx. I grant you, 3 Bx is quite a lot.

Please understand that I am not saying that use of refractometer is your problem. Just that it could be. Perhaps the wort was indeed of normal gravity.

I have used the refractometer for a couple of years now and get reliable readings with it. I believe the #'s.

IslandLizard said:
Although that's true, if you didn't change anything on the milling, chances are that your wheat wasn't crushed well at all. Wheat kernels are much smaller and harder than barley. A larger percentage may have passed through whole. If you still can, check your spent grains for large grain bits.

Since there was wheat, I double milled and checked it thoroughly before the brew. That is not the source of the inefficiency.

Although rice hulls will soak up some wort, it is quite minimal, maybe an ounce or two.

IDK??? I guess I am just going to enjoy a Summer Wheat that is more session-able than originally intended.

Looking again at Beersmith
Measured Mash efficiency = 72.5
Measured efficiency = 56.5

Again, there was nothing really different from previous brews and I usually hit my gravities very closely. ????

doug293cz · May 18, 2015

I can't see anything obvious that would cause efficiency that low. Is there any possibility that you got some unmalted grain by mistake?

Brew on :mug:

FatDragon · May 18, 2015

kh54s10 said:
Looking again at Beersmith
Measured Mash efficiency = 72.5
Measured efficiency = 56.5

Again, there was nothing really different from previous brews and I usually hit my gravities very closely. ????

Not sure why you got such low efficiency - the above posters have already addressed some possible reasons - but your Beersmith numbers are the result of a data entry error. I've got my Beersmith set to metric units, but recreating the grainbill and OG of that brew within a few grams/milliliters here and there, I got an estimated OG of 1.046 (at 68% efficiency) and an actual efficiency in the low 40's. I then popped over to the "Mash" tab and looked down at the "Mash Efficiency" readout - lo and behold, 73.4%! How could that be? Because while I changed the final volume and OG numbers on the "Design" tab, I didn't adjust any of the "Volume and Gravity in Boiler" variables on the "Mash" tab. Beersmith's calculating your mash efficiency based on the default numbers in the "Meas Pre-Boil Vol" and "Meas Pre-Boil Gravity" fields, rather than whatever your actual pre-boil volume and gravity were, so the mash efficiency calculations have nothing to do with your actual brew. If you took a pre-boil gravity sample and have a good estimate of your pre-boil volume, pop those numbers in there and your efficiency reading will miraculously (and maybe a bit depressingly) plummet to reflect what actually happened with this beer.

kh54s10 · May 18, 2015

FatDragon said:
Not sure why you got such low efficiency - the above posters have already addressed some possible reasons - but your Beersmith numbers are the result of a data entry error. I've got my Beersmith set to metric units, but recreating the grainbill and OG of that brew within a few grams/milliliters here and there, I got an estimated OG of 1.046 (at 68% efficiency) and an actual efficiency in the low 40's. I then popped over to the "Mash" tab and looked down at the "Mash Efficiency" readout - lo and behold, 73.4%! How could that be? Because while I changed the final volume and OG numbers on the "Design" tab, I didn't adjust any of the "Volume and Gravity in Boiler" variables on the "Mash" tab. Beersmith's calculating your mash efficiency based on the default numbers in the "Meas Pre-Boil Vol" and "Meas Pre-Boil Gravity" fields, rather than whatever your actual pre-boil volume and gravity were, so the mash efficiency calculations have nothing to do with your actual brew. If you took a pre-boil gravity sample and have a good estimate of your pre-boil volume, pop those numbers in there and your efficiency reading will miraculously (and maybe a bit depressingly) plummet to reflect what actually happened with this beer.

I have never changed the numbers there and never missed by as much.

I just changed the numbers and it shows estimated mash eff 69.4
and measured mash eff 64.7 the measured efficiency on the design page still says 56.5 So that made changed it a little.

Now I wonder why, if I never changed the numbers on the mash page before, why do I usually get the proper pre-boil gravity and OG??

ajdelange · May 18, 2015

I have used the refractometer for a couple of years now and get reliable readings with it. I believe the #'s.

Perhaps you do but you shouldn't unless you have checked them against a hydrometer in which case I don't see any point in using the refractometer. Refractometers really do not belong in the brewery unless they are properly calibrated for the type of beer being brewed against a more reliable instrument.

leesmith · May 18, 2015

Any changes to your system.?
I do ebiab and just changed to using a sprayer head along with a basket to hold the bag and grains.
My efficiency went way down, but I also learned the difference between mash efficiency and brewhouse....just need to adjust my brewhouse efficiency to lower my mash one from 90 something to 75 or so. Basically a little more malt. I'll see if this works during the next brew. If not I'll switch back to my old way.

Oh and my refractometer can be all over the place...I keep distilled water on hand to calibrate during the brew day.

ajdelange · May 18, 2015

Distilled water will set the 0 point but cannot compensate for slope changes which are evidently associated with variability in the sugar spectrum.

leesmith · May 18, 2015

Yeah
I'm beginning to get annoyed with my refractometer to the point of using my hydrometer. They do match roughly which is good enough for me. I worry about the drastic swings (a whole brix point) of the refractometer and not being aware of it....that's where things can get really messed up.

Anyways...one other thing I've wondered and haven't gotten a clear answer: could the age of the grain cause the efficiency to be off?

ajdelange · May 18, 2015

If malt goes 'slack' (takes up a lot of water) then clearly it contains less potential extract per pound than low moisture content malt. This might account for a few percent decrease in efficiency but not 10's of percent.

Owly055 · May 18, 2015

There are numerous reasons your OG might be low.......... But no reason why Beersmith should say your efficiency was high when projected OG is low...... that simply does not compute at all. Your OG is what determines your mash efficiency... period.

H.W.

FatDragon · May 18, 2015

kh54s10 said:
I have never changed the numbers there and never missed by as much.

I just changed the numbers and it shows estimated mash eff 69.4
and measured mash eff 64.7 the measured efficiency on the design page still says 56.5 So that made changed it a little.

Now I wonder why, if I never changed the numbers on the mash page before, why do I usually get the proper pre-boil gravity and OG??

Beersmith calculates Mash Efficiency and Measured Efficiency from completely different user-entered variables - Mash Efficiency comes from Pre-Boil Gravity and Volume, where Measured Efficiency comes from OG and Measured Batch Size - both measured after the boil. In real life, mash efficiency has a direct impact on what Beersmith calls "Measured" efficiency. In Beersmith, the numbers don't meet one another, so you could get vastly disparate numbers there if you put in the wrong measurements (for example, entering your post-boil OG in the pre-boil OG field).

If I were staring over your shoulder and knew all of your brewday numbers (including some which you may not have measured), I could probably tell you where you messed up the data entry and caused Beersmith to give you some false readouts, but all I can tell you with certainty is that any disparity between your actual efficiency and what Beersmith is saying about your efficiency is a data entry issue - maybe you put the wrong numbers in certain fields, maybe you don't have the right numbers for certain fields, maybe you didn't enter anything in certain fields and Beersmith is calculating from its default numbers. I recommend you dig deeper into how to use Beersmith to get a more accurate understanding of your brew, or just ignore all that auxillary stuff and understand that it might not reflect your real-life numbers. Either way, while it's important to understand your software if you're relying on it for understanding and tweaking your brewing process, the first thing to do is diagnose why you got such low efficiency in the first place and work on fixing that.

kh54s10 · May 18, 2015

FatDragon said:
Either way, while it's important to understand your software if you're relying on it for understanding and tweaking your brewing process, the first thing to do is diagnose why you got such low efficiency in the first place and work on fixing that.

As I have said, there was nothing that I can determine that I did differently on this batch. I may never know why I missed my OG by so much.

kh54s10 · May 18, 2015

doug293cz said:
I can't see anything obvious that would cause efficiency that low. Is there any possibility that you got some unmalted grain by mistake?

Brew on

I doubt there is any chance it was unmalted. http://www.farmhousebrewingsupply.com/white-wheat-cmc-1-lb/

ajdelange said:
I have used the refractometer for a couple of years now and get reliable readings with it. I believe the #'s.

Perhaps you do but you shouldn't unless you have checked them against a hydrometer in which case I don't see any point in using the refractometer. Refractometers really do not belong in the brewery unless they are properly calibrated for the type of beer being brewed against a more reliable instrument.

I have not checked directly against a hydrometer sample and probably will next brew day. But then again I am usually within a point or two of what I expect, this time it was way off. I don't think the refractometer is the issue.

leesmith said:
Any changes to your system.?
I do ebiab and just changed to using a sprayer head along with a basket to hold the bag and grains.
My efficiency went way down, but I also learned the difference between mash efficiency and brewhouse....just need to adjust my brewhouse efficiency to lower my mash one from 90 something to 75 or so. Basically a little more malt. I'll see if this works during the next brew. If not I'll switch back to my old way.

Oh and my refractometer can be all over the place...I keep distilled water on hand to calibrate during the brew day.

I checked the calibration several times during the day. And no other changes.

ajdelange said:
Distilled water will set the 0 point but cannot compensate for slope changes which are evidently associated with variability in the sugar spectrum.

This is true but again, I have not often been off by more than a couple points. This time it was way off.

I think I have learned a little about the efficiency numbers and calculations, but still don't have a clue why this brew went awry... I plan to brew tomorrow so I'll soon know if I will have a recurring problem. Now to decide what to brew?!!?

FatDragon · May 18, 2015

kh54s10 said:
As I have said, there was nothing that I can determine that I did differently on this batch. I may never know why I missed my OG by so much.

Sure. My last sentence there was as much an aside as anything: the question you posed in the OP seemed to be more about Beersmith than your actual efficiency, so that's what I've addressed primarily.

At the same time, barring a measurement error that could be user- or equipment-based, something was different this time around. Maybe your grains were really old and had somehow lost a great deal of their potential gravity. Maybe your scale is normally set to kg and you accidentally had it set to pounds. Maybe your mash temps were way off due to a thermometer issue. Maybe you straight-up forgot one of your grains. It's probably not one of those, but if your gravity and volume measurements are all correct, your process didn't change, and your efficiency dropped by over 20%, something was different. Extraction can fluctuate by a couple points across otherwise-identical brewdays, but nowhere close to this much.

kh54s10 · May 19, 2015

FatDragon said:
Sure. My last sentence there was as much an aside as anything: the question you posed in the OP seemed to be more about Beersmith than your actual efficiency, so that's what I've addressed primarily.

At the same time, barring a measurement error that could be user- or equipment-based, something was different this time around. Maybe your grains were really old and had somehow lost a great deal of their potential gravity. Maybe your scale is normally set to kg and you accidentally had it set to pounds. Maybe your mash temps were way off due to a thermometer issue. Maybe you straight-up forgot one of your grains. It's probably not one of those, but if your gravity and volume measurements are all correct, your process didn't change, and your efficiency dropped by over 20%, something was different. Extraction can fluctuate by a couple points across otherwise-identical brewdays, but nowhere close to this much.

I agree.

My first thought was that I didn't understand the efficiencies in Beersmith. I wasn't totally off base and I have learned a little more.

I don't believe I made any measurement errors but must have, somewhere.

I guess I will never figure this one out?!?!?

stpug · May 19, 2015

Recipe:
......4 lbs white wheat malt
......3 lbs Rahr 2 row
......2 lbs Weyermann Munich I
......rice hulls

......Mash temperature 148 degrees
......batch sparge: single sparge this time (sounds like no sparge though)

Equipment Setup:
......HLT is a 10 gallon pot
......MLT is a 10 gallon Rubbermaid cooler w/braid (minimal loss)
......BK is a 10 gallon kettle

Beersmith Data:
......estimated OG was 1.045
......measured OG was 1.031

......Beersmith says:
......Measured Mash efficiency = 72.5
......Measured BH efficiency = 56.5

......Changed the numbers and Beersmith shows:
......Estimated Mash efficiency = 69.4
......Measured Mash efficiency = 64.7
......Measured BH efficiency = 56.5

Questions:
......Just wondering why I got relatively good mash efficiency #'s and low OG? I may never know why I missed my OG by so much

To answer your question above:
You did not get good mash efficiency. Mash efficiency should almost always be approaching 90% as this means that you're getting most of the potential sugars out of the grain into your brewpot - how you lose them afterwards is up to you. Your low OG (i.e. brewhouse efficiency) is another indicator that your mash efficiency was very poor, as it directly depends on mash efficiency. Brewhouse efficiency is always <= your mash efficiency.

You are correct that you may never know why you missed the OG (i.e. missed getting the potential sugars from the grain) by so much. It's pretty much a guessing game at this point.

My two guesses are:
1) Some pounds of grain were missing from your grist
2) Some pounds of grain were never milled
3) The milling of the entire grist was very poor
4) The devil came up and slurped them out of your pot while you were not looking

Below is an example beersmith file of the beer your brewed based on my understanding from this thread. I wonder how much yours differs from this one.
View attachment WheatExample.bsmx

ajdelange · May 19, 2015

The possibilities are:

1)The amounts of grain that actually made it into the mash tun were substantially less than reported (weighing error - check scale)
2)The grind was terrible - check mill (presumably it's still set the same)
3)The gravity of the mash was measured in error (use hydrometer)

Even if he'd had only 60% overall efficiency he should have gotten about 1.050 which, with 75% attenuation, would give a final AE of about 1.012. If indeed the realized OE was only 1.031 the final AE would, assuming equal apparent attenuation, be about 1.008. Some time has passed. What's the gravity now and/or what does a force test show? If 1) or 2) above pertains the beer will be a small beer indeed. If it's 3), the beer may be fine.

Owly055 · May 20, 2015

I use Brewer's Friend.... a simpler program that doesn't confuse the issue of efficiency. It has only one efficiency, and that's brewhouse efficiency which is everything rolled into one as far as I can tell.

My take on efficiency is that the only reason for having two efficiency ratings is the addition of fermentables to the boil. I'm talking about things like corn sugar, honey, etc, which do not have to be converted to ferment.

The ONLY efficiency rating that matters is conversion efficiency (mash efficiency), it's the only one you have control over. Nothing after the mash changes that, but if you take a gravity post boil, it will include the sugars you mashed and the ones you added to the boil. So if you add a lot of sugars to the boil, those sugars are 100% efficient.... they are already converted to sugar. That masks your mash efficiency unless you account for it mathematically. Your measured efficiency should NEVER be less than your mash efficiency if your liquid volumes are correct and your readings right.

H.W.

I thought I understood efficiency...

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