Thoughts on low efficiency.

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RBBrewing

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Interest to hear some opinions on why I have such low efficiency. Upgraded my set up and seem to consistently have issues with my BIAB efficiency. My batch that was attempted today was an IPA that according to beersmith i should have been at roughly 1.081 but i finished at 1.063.
- 20 gallon CH kettle 220
- 10 gallon batch
- 16.5 gallons of starting water. (well water) (2.12 quarts per lb)
- 31 pounds of various grains
- Milled twice through down to .0030
- Mash Strike 160 degrees
- Mashed at 152 degrees plus or minus 1 degree for 60 minutes
- Mash out at 168 degrees
- Mash PH was 5.4
- Pre boil gravity 1.056
- Final gravity 1.063 (measured with refract after cooling to 75 and tilt in fermenter)

Although the mash PH seems to be good could there be an issue with my well water profile that is preventing a higher efficiency? Thoughts? Photos of the milled grain. Thank you.
 

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You're missing some vital information. Volume at pre-boil?

Have you dialed in your software to reflect your actual, observed, carefully measured loss to grain absorption?
 
You're missing some vital information. Volume at pre-boil?

Have you dialed in your software to reflect your actual, observed, carefully measured loss to grain absorption?
Pre boil volume was 14 gallons. my software currently reflects that my pre boil should have been 14.21 gallons. I raise temp to mash out and then hang drain. I don't do any sort of pressing of the grains.
 
according to beersmith i should have been at roughly 1.081 but i finished at 1.063.
Beersmith doesn't know what your system efficiency is. Only you can tell it what it is and then scale the recipe to make up for it.

In general, a gravity drain of a BIAB with no squeezing on a 10 gallon batch would land around 60% brewhouse efficiency. You can usually get that up to 65% with a moderate squeezing of the bag.
 
- Milled twice through down to .0030

If that wasn't an obvious typo (witness the picture) the subject line would have regarded a cemented mash 😁

I don't BIAB but my barley mill is gapped to 0.030" (really) and my wheat and oats mill is set to 0.020". I'd expect a tighter crush than 0.030" for BIAB...

Cheers!
 
Interest to hear some opinions on why I have such low efficiency. Upgraded my set up and seem to consistently have issues with my BIAB efficiency. My batch that was attempted today was an IPA that according to beersmith i should have been at roughly 1.081 but i finished at 1.063.
- 20 gallon CH kettle 220
- 10 gallon batch
- 16.5 gallons of starting water. (well water) (2.12 quarts per lb)
- 31 pounds of various grains
- Milled twice through down to .0030
- Mash Strike 160 degrees
- Mashed at 152 degrees plus or minus 1 degree for 60 minutes
- Mash out at 168 degrees
- Mash PH was 5.4
- Pre boil gravity 1.056
- Final gravity 1.063 (measured with refract after cooling to 75 and tilt in fermenter)

Although the mash PH seems to be good could there be an issue with my well water profile that is preventing a higher efficiency? Thoughts? Photos of the milled grain. Thank you.
I get your grain absorption rate as 0.081 gal/lb which is reasonable for a thorough bag drain without squeezing.

At 100% conversion efficiency, your pre-boil SG should have been 1.060. With pre-boil at 1.056, your conversion efficiency was 92 - 93%, which isn't terrible, but could be higher (100% conversion is achievable.) Your lauter efficiency was 77%, which is lower than you might have expected due to the large grain bill. Mash efficiency was 71.3% (mash efficiency = conversion efficiency * lauter efficiency.)

You didn't list a post-boil volume, but assuming your pre-boil volume, pre-boil SG, and post-boil SG (OG) measurements are accurate, then your post-boil volume would have been:

14.0 gal * 56 / 63 = 12.44 gal​
If you had a 100% conversion efficiency, and had a pre-boil SG of 1.060, you would have needed to boil until a volume of:

14.0 gal * 60 / 81 = 10,37 gal​
To achieve an OG of 1.081.

My calculations were done using my mash & lauter simulator spreadsheet.

Brew on :mug:
 
Timely...
I too recently added a B to my Brew in a Three Vessel System (BTVS(B))?
My efficiency went through the floor.

I'm milling finer.
I have a bag in my bottom drain mash tun(with a false bottom).
I added recirc through the mash process(little to no effect).
I'm stirring at 15, 30, 45, and 60 mins(which I never had to do)
I still batch-sparge(in a bag), though I increased to ~1.75q/lb mash.
I'm hang-draining the bag, and adding to boil at ~20 mins left.

My efficiency went from ~75-8% to close to 60% by adding the bag and a bottom draining mash tun. ~13G keg to 15G keg. Added false bottom that leaves ~.5G not in the mash, but drains fully.

Still working on mine. I don't think it is a squeezing issue, but I am rinsing grains...
 
Timely...
I too recently added a B to my Brew in a Three Vessel System (BTVS(B))?
My efficiency went through the floor.

I'm milling finer.
I have a bag in my bottom drain mash tun(with a false bottom).
I added recirc through the mash process(little to no effect).
I'm stirring at 15, 30, 45, and 60 mins(which I never had to do)
I still batch-sparge(in a bag), though I increased to ~1.75q/lb mash.
I'm hang-draining the bag, and adding to boil at ~20 mins left.

My efficiency went from ~75-8% to close to 60% by adding the bag and a bottom draining mash tun. ~13G keg to 15G keg. Added false bottom that leaves ~.5G not in the mash, but drains fully.

Still working on mine. I don't think it is a squeezing issue, but I am rinsing grains...
Is your bag big enough that the bag is in contact with the walls and false bottom of the mash vessel during the mash? With a properly sized bag, you should not have a significant change in efficiency, if your sparge process is similar to what you did without the bag.

To really diagnose your issue, we need to have the following data for one or more brew sessions for the original system and the new system:
  • Grain bill weight
  • Strike water volume
  • End of mash wort SG (after homogenizing and prior to adding any sparge water)
  • Sparge water volume & sparge process
  • Pre-boil volume
  • Pre-boil SG
Brew on :mug:
 
Have you calibrated your mash thermometer in ice water and boiling water corrected for your elevation? Have you zeroed your hydrometer and refractometer in plain cool water?
 
I highly recommend that you rest your mash for 90 min. to 2 hours. It will surprise you the efficiency boost just a little time will give you. Everyone seems to be focused on mill gap but time is the more important factor.

Commercial brewers of yesteryear mashed for 2 hours as a standard practice. Learn from the past.
 
My efficiency bumped up a good bit by doing two changes to my typical single step mash at 152.5°F.

1) I mash in 3 steps.
Mash in at 135°F. Hold for 10m
Mash at 143°F - hold 15 min.
Mash at 152.5 for 40 m
Mash out at 167 for 10 m

2) in lieu of sparging hot water over the malt pipe ... I take the bag out and place it in a massive brew kettle... Pour hot water over it (170°) ... Let it deep a few minutes and dump the new wort back in the bucket back into the your brew machine.

This brought my efficiency up about 10 points. YMMV. Good luck.
 
- Final gravity 1.063 (measured with refract after cooling to 75 and tilt in fermenter)
You mean OG don't you?

Are you making certain all your malts are whetted and not forming doughballs?

I have had bags that I've made myself and bought off of Amazon that were too fine a mesh and didn't let the wort circulate enough through the malts.

Though I think your main issue is you don't have your equipment and your efficiencies set up in your software.

Your efficiency doesn't have to be any particular number. It just needs to be a number you can get consistently.

Then with any recipe you get from others, you adjust the fermentable ingredients, water and perhaps some other things to match your efficiency and get the same OG and volume as did the recipe you are trying to use.
 
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If that wasn't an obvious typo (witness the picture) the subject line would have regarded a cemented mash 😁

I don't BIAB but my barley mill is gapped to 0.030" (really) and my wheat and oats mill is set to 0.020". I'd expect a tighter crush than 0.030" for BIAB...

Cheers!
Yes! A typo, but would likely increase the efficiency with a constant stir! lol. I'm going to mill it much finer this next brew and keep better notes. Thanks everyone for the insight.
 
Have you calibrated your mash thermometer in ice water and boiling water corrected for your elevation? Have you zeroed your hydrometer and refractometer in plain cool water?
A new hydrometer is on order as i cant find my previous. the refractometer was calibrated in distilled water at roughly 75 degrees.
 
I get your grain absorption rate as 0.081 gal/lb which is reasonable for a thorough bag drain without squeezing.

At 100% conversion efficiency, your pre-boil SG should have been 1.060. With pre-boil at 1.056, your conversion efficiency was 92 - 93%, which isn't terrible, but could be higher (100% conversion is achievable.) Your lauter efficiency was 77%, which is lower than you might have expected due to the large grain bill. Mash efficiency was 71.3% (mash efficiency = conversion efficiency * lauter efficiency.)

You didn't list a post-boil volume, but assuming your pre-boil volume, pre-boil SG, and post-boil SG (OG) measurements are accurate, then your post-boil volume would have been:

14.0 gal * 56 / 63 = 12.44 gal​
If you had a 100% conversion efficiency, and had a pre-boil SG of 1.060, you would have needed to boil until a volume of:

14.0 gal * 60 / 81 = 10,37 gal​
To achieve an OG of 1.081.

My calculations were done using my mash & lauter simulator spreadsheet.

Brew on :mug:
Yeah i seemed to have started with too much water on this batch. I did end up boiling down to roughly 10.5 gallon post boil. at 10.5 gallons i was at 1.063.
 
You mean OG don't you?

Are you making certain all your malts are whetted and not forming doughballs?

I have had bags that I've made myself and bought off of Amazon that were too fine a mesh and didn't let the wort circulate enough through the malts.

Though I think your main issue is you don't have your equipment and your efficiencies set up in your software.

Your efficiency doesn't have to be any particular number. It just needs to be a number you can get consistently.

Then with any recipe you get from others, you adjust the fermentable ingredients, water and perhaps some other things to match your efficiency and get the same OG and volume as did the recipe you are trying to use.
Yes OG, typo.

I am very slow to pour in grain and stir with a giant whisk careful to prevent all dough balls. The set up i have is like a mesh basket and not an actually bag. I try to stir it roughly every 10 minutes throughout the mash.

I do agree it is likely my software and my inputs causing my low readings. I currently am trusting a prebuilt software set up for my brewing configurations. Probably where my problem is.
 
I highly recommend that you rest your mash for 90 min. to 2 hours. It will surprise you the efficiency boost just a little time will give you. Everyone seems to be focused on mill gap but time is the more important factor.

Commercial brewers of yesteryear mashed for 2 hours as a standard practice. Learn from the past.
I beg to differ. Crush size is every bit as important as mash time. The rate limiting step in the saccharification process is the gelatinization of the starch. Starch cannot be hydrolyzed until after it has been gelatinized. Gelatinization starts at the surface of the grits and proceeds inwards towards the center. (The gelatinized outer portion of a grit can undergo hydrolysis while the inner portion is still waiting to be gelatinized.) The smaller the grit, the faster it will achieve complete gelatinization, and the faster it will complete hydrolysis. So, you can get 100% conversion of fine crushes faster than you can get 100% conversion of coarse crushes. @RM-MN , who crushes very fine has shown complete conversion in under 20 minutes. You are correct that longer mashes can give higher conversion efficiency in cases where conversion is incomplete after 60 minutes.

A good way to determine how long it takes your mash to complete, with your crush level, is to monitor the SG of the wort during the mash. A good plan is to start monitoring at about 45 minutes, and then every 15 minutes thereafter. When the SG does not increase from one sample to the next, your mash is done (either you have reached 100% conversion or your enzymes have all denatured.) You need to be sure all of the wort is well homogenized before taking an SG sample to avoid the possibility of erroneous high or low readings. A refractometer is very helpful for making these SG measurements.

Brew on :mug:
 
Yeah i seemed to have started with too much water on this batch. I did end up boiling down to roughly 10.5 gallon post boil. at 10.5 gallons i was at 1.063.
If you had boiled 14 gal of 1.056 SG wort (56 pts/gal) down to 10.5 gal, you would have ended up with:

56 pts/gal * 14 gal / 10.5 gal = 74.7 pts/gal, or 1.074 - 1.075 SG​
This calculation indicates that some or all of your volume and/or SG measurements were in error.

Brew on :mug:
 
A good way to determine how long it takes your mash to complete, with your crush level, is to monitor the SG of the wort during the mash. A good plan is to start monitoring at about 45 minutes, and then every 15 minutes thereafter. When the SG does not increase from one sample to the next, your mash is done (either you have reached 100% conversion or your enzymes have all denatured.)
This is a good plan but change the timing if you have a really fine crush. Start monitoring at 1 minute and then every 1 minute thereafter. It will be a real eye opener to those who think a 60 to 90 minute mash is needed.
 
This is a good plan but change the timing if you have a really fine crush. Start monitoring at 1 minute and then every 1 minute thereafter. It will be a real eye opener to those who think a 60 to 90 minute mash is needed.
If someone crushes very fine, then yes, earlier initial sampling and shorter sampling intervals are appropriate. For more mainstream crushes (e.g. store crushed grain), experience (many HBT reports) has shown that a large number of homebrewers do not get 100% conversion after the typical 60 minute mash. And, this is what my suggested sampling protocol is targeted at.

Brew on :mug:
 
@doug293cz So 100% conversion means all the available starches are converted into sugar, right? But we know not all sugar is fermentable. How might an extended mash time affect the kind of sugar that results?
 
@doug293cz So 100% conversion means all the available starches are converted into sugar, right? But we know not all sugar is fermentable. How might an extended mash time affect the kind of sugar that results?
Unless you do an extended mash at 145°F (63°C), or so, it shouldn't make much difference in the fermentability. Alpha amylase by itself can reduce starch to fermentable sugars and limit dextrins (residual branched fragments of amylopectin, with ~4 glucose units on all three branches of the molecule, which are unfermentable.) Fermentability of the wort is primarily determined by how much activity you get from the limit dextrinase enzyme (which hydrolyzes the branch bonds in dextrins, allowing more fermentable sugars to be created and less dextrins left in the wort.) Limit dextrinase denatures fairly rapidly above about 150°F (66°C) so, won't be around to turn any remaining dextrins into fermentable sugar during an extended mash at higher temps.

Very fine crushes, which gelatinize quickly, can result in higher fermentability wort than coarse crushes, because more starch is available for hydrolysis before the limit dextrinase has all been denatured,

Brew on :mug:
 

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In addition to (or in lieu of) sampling SG every 15 minutes, you can use a drop of iodine to test for remaining starch in your wort. A little wort on a white plate with a drop of iodine in it will stay reddish if the starch has all been converted. Any starch remaining will turn the sample purple.

I do it every 15 minutes and usually have clear results by the 45-50 minute mark.
 
In addition to (or in lieu of) sampling SG every 15 minutes, you can use a drop of iodine to test for remaining starch in your wort. A little wort on a white plate with a drop of iodine in it will stay reddish if the starch has all been converted. Any starch remaining will turn the sample purple.

I do it every 15 minutes and usually have clear results by the 45-50 minute mark.
You really need to sample some of the grain as well, as that is where the non-soluble residual starch hides. The SG sampling method does not have this limitation, which is why I recommend it over the iodine test.

Some brewers complain that if they include grain in their iodine test sample, they don't get a negative (no starch remaining) result. Well, that is because your mash isn't done.

Brew on :mug:
 
I think I am right on this, please correct me if I am wrong. Conversation isn’t the whole picture. What kind of sugar it’s converted to can change over more time even after the iodine test shows complete conversion. Longer mash time can lead to a more fermentable wort after conversion is complete.
 
Longer mash time can lead to a more fermentable wort after conversion is complete.
But only if you're mashing fairly low. Your wort won't get much more fermentable once the limit dextrinase is denatured. See post #22:
Fermentability of the wort is primarily determined by how much activity you get from the limit dextrinase enzyme (which hydrolyzes the branch bonds in dextrins, allowing more fermentable sugars to be created and less dextrins left in the wort.) Limit dextrinase denatures fairly rapidly above about 150°F (66°C) so, won't be around to turn any remaining dextrins into fermentable sugar during an extended mash at higher temps.
 
In Beersmith before an actual making a batch, you must do a boil off to find the boil off rate and then input this boil off rate in the mash parameters. I just did it with plain water. This is the most reason for low gravity readings and low efficiency.
Other factors such as grain that cause lower eff such as wheat, flaked grains, cereal mash, are also a factor.
Brew in a bag has lower eff also.
 
Brew in a bag has lower eff also.

Nope. A single infusion with no sparge will reduce efficiency whether with BIAB or a traditional lauter. Adding a simple dunk sparge to your BIAB process will meet or beat the efficiency of your typical batch sparged traditional lauter.
 
So brewing another batch tomorrow morning. Was going to take additional notes outside of standard brew smith as listed below. Side question and maybe the term is wrong but would doing a full volume BIAB and then doing like a "recirculation sparge" at 170 degree help?

Version 2
Starter:
Water Start: # Gallons
Water Post Mash:
Water Pre Boil:
Water Post Boil:
Grind: Mill .033 / .025
Mash: LTR / Saccharification / Mash out / Sparge
Water PH: 5.4
Mash PH: #
10: #
20: #
30: #
40: #
50: #
Mash Out: #
Squeeze: #
Pre Boil: #
Post Boil Gravity: #
ABV: #
 
Side question and maybe the term is wrong but would doing a full volume BIAB and then doing like a "recirculation sparge" at 170 degree help?

If you're looking to complete conversion, yes/maybe. If the goal is to increase lauter efficiency (and thereby increase mash efficiency), no.

Lauter efficiency is all about rinsing the sugars from the grain bed. Clean, fresh water rinses more thoroughly than sugary water.
 
I used to be disappointed with my efficiency with BIAB, but now I:

a) crush very fine
b) squeeze the hell out of the bag
c) dunk sparge and
d) squeeze the hell out of the bag again.

Used to get 70% brewhouse efficiency or less (and inconsistent too) but last brew was 83%, which turned my DIPA into an Imperial.
 
I get ~76.70% consistent with an old cooler/manifold, but I now see that BIAB can better that, so I stand corrected.
 
I think I am right on this, please correct me if I am wrong. Conversation isn’t the whole picture. What kind of sugar it’s converted to can change over more time even after the iodine test shows complete conversion. Longer mash time can lead to a more fermentable wort after conversion is complete.

This is correct. The iodine test will show negative for starch when the maximum molecular weight of the polysaccharides is below a certain limit. But these higher molecular weight complex sugars/dextrins are not fermentable. Given enough time, amylase enzyme will reduce these higher molecular weight carbohydrates into fermentable sugars and limit dextrins (which are not fermentable.) So, more time after all of the starch is gone can allow the completion of hydrolysis (polysaccharide breakdown), and increase fermentability. '

This leads to another advantage of the SG monitoring method of determining conversion completion. To determine that the SG has stopped increasing, you have to have two consecutive samples that have the same SG. During the time between the last two samples (10 - 15 minutes), enzyme action can continue breaking down the larger polysaccharides into additional fermentable sugar.

But only if you're mashing fairly low. Your wort won't get much more fermentable once the limit dextrinase is denatured. See post #22:
This is partially correct. If hydrolysis is not complete (i.e. there are still more polysaccharides that can be broken down by amylase) then more time at any temperature (where the amylase has not been denatured) will increase the fermentability. But given two worts that have been hydrolyzed to the max that alpha amylase can achieve, the one that has seen more limit dextrinase action will have more fermentable sugars.

Limit dextrinase hydrolyzes the alpha 1-6 bonds that create the branch points in amylopectin. Each alpha 1-6 bond hydrolyzed reduces the number of ultimate limit dextrin molecules in the wort by 1. The more branch bonds are hydrolyzed, the fewer limit dextrins will be left in the resulting wort. Limit dextrinase denatures rapidly above about 150°F, so lower temperature mashes will have less dextrins than higher temp mashes.

Brew on :mug:
 
Nope. A single infusion with no sparge will reduce efficiency whether with BIAB or a traditional lauter. Adding a simple dunk sparge to your BIAB process will meet or beat the efficiency of your typical batch sparged traditional lauter.
This is correct. Mash efficiency has two factors: conversion efficiency (how much of the starch is converted to sugar) and lauter efficiency (how much of the sugar created makes it into the BK.) Mash efficiency = conversion efficiency * lauter efficiency. The use of a bag in the mash vessel does nothing to affect the conversion efficiency. Lauter efficiency is highly dependent on whether or not, and how, you sparge. Lauter efficiency is also affected by the grain absorption rate - gal/lb or L/kg, where the volume is the amount of wort retained in the spent grain, and weight/mass is the amount of grain used. Just hanging the BIAB bag provides a squeezing effect that will allow a grain absorption rate as low as 0.08 gal/lb, whereas a typical MLT gives a grain absorption rate of about 0.12 gal/lb. Thus a no sparge BIAB will have a slightly better lauter efficiency than a no sparge in a traditional MLT. If you add a dunk/batch sparge, you will get about a 8 - 8.5 percentage point increase in lauter efficiency, but the lower grain absorption with BIAB still results in higher lauter efficiency than a traditional MLT. This is summarized in the chart below:

Efficiency vs Grain to Pre-Boil Ratio for Various Sparge Counts.png


Brew on :mug:
 
If you're looking to complete conversion, yes/maybe. If the goal is to increase lauter efficiency (and thereby increase mash efficiency), no.

Lauter efficiency is all about rinsing the sugars from the grain bed. Clean, fresh water rinses more thoroughly than sugary water.
Yup. You can't reduce the amount of residual soap on a dish by swishing the dish around in the soapy water. Swishing the dish around in clean water removes most of the residual soap. Same principle with recirculation vs. sparging.

Brew on :mug:
 
In Beersmith before an actual making a batch, you must do a boil off to find the boil off rate and then input this boil off rate in the mash parameters. I just did it with plain water. This is the most reason for low gravity readings and low efficiency.
Other factors such as grain that cause lower eff such as wheat, flaked grains, cereal mash, are also a factor.
Brew in a bag has lower eff also.
Boil-off has very little effect on efficiency, but does affect OG significantly. If you start with more water, you will have slightly higher lauter efficiency, but the effect is rather small if you are only talking about a fraction of a gallon difference in total water used. Once the mash is lautered, the mash efficiency is fixed, and how much you boil off has no effect after that.

Wheat generally has the same, or even slightly higher, potential than barley. The problem with wheat is that the kernels are smaller, and with coarser crushes, you may have a significant fraction of the wheat kernels uncrushed. This will prevent you from getting 100% conversion of the wheat, and lower your conversion efficiency.

Brew in a bag has been discussed in my, and others', previous posts.

Brew on :mug:
 
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