Please help me improve my BIAB efficiency

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Calypso

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Since switching to partial mash from extract, I've been struggling with really lousy mash efficiency. I would love some ideas on how to fix it. The last three beers I've made have had efficiencies ranging from 58-62%.

Some notes:

1) I double crush my grain at the homebrew store, so unless I buy my own mill, I can't crush it any finer. (If you say I need to crush my own grain, so be it.)
2) I do full volume boils. My general approach is 7.5 gallons of water in, with no more than 9 pounds of grain. If I need more sugars than that, the rest is added during the boil as extract.
3) I do squeeze the bag, hard.
4) I don't do a sparge.
5) I don't do a mash out.

Basically, once conversion is done, I pull out the bag and let it drain in a bucket over an inverted colander. At the same time, I apply the heat to begin bringing the wort to a boil. Once the bag is done draining, I give it a good squeeze, toss the grains, and pour the liquid from that bucket back into the brew kettle.

What am I doing wrong?
 
Well, I'll tell ya, I got my biggest efficiency boost when I got a corona-style mill and made an ugly-junk mill in a bucket. I grind so that there is significant flour since there's no stuck sparge worry for BIAB. I'm generally hitting 80-85%

in order of easiest to hardest suggestions:

1) add a mash out... I don't expect much from this, but who knows. I generally do a dunk sparge at mash out temps.

2) add a sparge step. Either dunk or pour-over-the-bag. Seems like I recall some folks here mentioning picking up a few points from this. Withhold a gallon or so of your mash volume to use as sparge. I pull the bag, squeeze like hell, dunk sparge with about 1.5 gal at mash out temps in a separate pot for 10-15 minutes, pull the bag and squeeze like hell. Then add any further drippings to the boil about halfway through.

3) triple crush at LHBS

4) get a mill
 
I partial boil BIAB. Definitely add a dunk sparge in 1.5G or so at 160° or so. Also found that stirring the mash prior to lifting/draining really helps. But adding dunk made biggest diff.
 
OP what temp and how long are you mashing?
Also how busy is your LHBS on average? Stale/old or improperly stored grains can cause mash efficiency issues.
 
I bought a Barley Crusher grain mill to crush my own to get a more uniform crush at the factory-notches for .039 inch. I mash up to 8.6lbs of grains in about 2 1/4 gallons of spring water @ 153-155F. I dunk (read batch) sparge in a separate kettle of 2 1/4 to 2 1/2 gallons of spring water @ 168F. I stir the bag of grains in the sparge kettle to get more out of them. Drain again & add sparge wort to main wort, shooting for no more than 4 gallons boil volume in my 5 gallon SS kettle. My Efficiency went up significantly doing this.
 
I think too much water may be contributing to your problem. There are only so many enzymes in a mash, and if you have a lot of water, they can become really dispersed and the whole mash process is much slower.

Try mashing in about 3 gallons of water, remove, drain, and then sparge in a second pot with about 3 gallons more water at about 170 F for 10 minutes, then drain/squeeze.

Crush could be another significant item. Get a grain crusher, a corona mill works great if you don't want to spend much. You should be able to find a new one for about $35 on-line. Going from 60 to 80% efficiency (a 33% improvement), will pay for the mill really quickly.
 
I don't believe in sparging. I mash in the full strike volume of water. As long as you've calculated to use the correct amount of water for the OG you want, then mashing in that amount of water will work great. Remember, all that water in the pot means the solutes in the bag will tend to move into the solution outside the bag. Some of us think that in the world of BIAB, sparging is what you do when you don't have a big enough brew pot to handle the full vol of water when mashing. Yes, some folks will argue this, but if you want to learn a lot about the process of BIAB, try going over to BIABrewer.info and do some reading. Those guys are all BIAB all the time and they helped me out a lot. Get a free copy of the BIABacus spreadsheet, which has replaced Beersmith for me.

+1 on getting a mill. I have a BC set to the factory setting (.039). I grind twice. Works great. Don't let people tell you that you need to grind finer than in the traditional method. That's a bunch of hooey.

Make sure your thermometer is accurate. This is huge.

I do squeeze the bag to get the excess out. I don't go crazy with it. I like my bag.
 
How long to you stir at dough-in? In addition to the useful things already mentioned, that can have an impact on your efficiency.

I shoot for and get a pretty steady 76% with my E-BIAB at full volume and recirculating.
 
This may sound really dumb... I don't BIAB, but I had lousy efficiency until I stirred the grain every 15 minutes. Even though you have a bag and squeeze, I imagine stirring is still important. Do you do that?
 
Don't let people tell you that you can't get a stuck sparge with BIAB either. Try a 50% rye recipe.
 
I don't believe in sparging. I mash in the full strike volume of water. As long as you've calculated to use the correct amount of water for the OG you want, then mashing in that amount of water will work great. Remember, all that water in the pot means the solutes in the bag will tend to move into the solution outside the bag. Some of us think that in the world of BIAB, sparging is what you do when you don't have a big enough brew pot to handle the full vol of water when mashing. Yes, some folks will argue this, but if you want to learn a lot about the process of BIAB, try going over to BIABrewer.info and do some reading. Those guys are all BIAB all the time and they helped me out a lot. Get a free copy of the BIABacus spreadsheet, which has replaced Beersmith for me.

+1 on getting a mill. I have a BC set to the factory setting (.039). I grind twice. Works great. Don't let people tell you that you need to grind finer than in the traditional method. That's a bunch of hooey.

Make sure your thermometer is accurate. This is huge.

I do squeeze the bag to get the excess out. I don't go crazy with it. I like my bag.

I like my bag also! :ban:

seriously, a bunch of good advice was given here. Beersmith handles BIAB pretty well in my opinion. I crush pretty normal myself (a touch finer than typical LHBS which I think we can all agree is more appropriate), don't dunk sparge or squeeze too hard, full volume mash and have been getting between 70-75% depending on grain bill. (which is about all I ever got batch sparging). I'm fine with these numbers. Every system is different. One thing I can tell you is that I DO mashout as it is very easy to do on my system.

Mostly I just wanted to say I like my bag! :ban:
 
I think too much water may be contributing to your problem. There are only so many enzymes in a mash, and if you have a lot of water, they can become really dispersed and the whole mash process is much slower.

Try mashing in about 3 gallons of water, remove, drain, and then sparge in a second pot with about 3 gallons more water at about 170 F for 10 minutes, then drain/squeeze.

Crush could be another significant item. Get a grain crusher, a corona mill works great if you don't want to spend much. You should be able to find a new one for about $35 on-line. Going from 60 to 80% efficiency (a 33% improvement), will pay for the mill really quickly.

I think you might be down the right path but looking at the wrong solution. Certainly sparging may help efficiency but it isn't because he is mashing with too much water. Perhaps that volume of water is contributing to a poor mash pH and that is contributing to poor mash efficiencies. With today's highly modified grains with all their diastatic power, I highly doubt he is lacking the enzymes necessary to complete conversion. Only an Iodine test could confirm this. On the same note, without a mash pH measurement we are only speculating on that front too. My feeling is as though it would more likely be a mash pH problem than a lack of enzyme problem. Further, there has been research showing that mash thickness has more influence on which enzymes are active than anything else. I read an article in I think BYO recently that showed that basically a thin mash produces a more fermentable wort. Which may lead to speculation that perhaps the mash temp is too low. I seem to have noticed this first hand on my BIAB system. Mashing at 154 on my BIAB system is like mashing at 150 on my old batch spare system.

My question for Calypso is are you doing anything with your water? What kind are you using(tap water, Reverse Osmosis, Distilled), any addition or treatments?
 
Well, I'll tell ya, I got my biggest efficiency boost when I got a corona-style mill and made an ugly-junk mill in a bucket. I grind so that there is significant flour since there's no stuck sparge worry for BIAB. I'm generally hitting 80-85%

in order of easiest to hardest suggestions:

1) add a mash out... I don't expect much from this, but who knows. I generally do a dunk sparge at mash out temps.

2) add a sparge step. Either dunk or pour-over-the-bag. Seems like I recall some folks here mentioning picking up a few points from this. Withhold a gallon or so of your mash volume to use as sparge. I pull the bag, squeeze like hell, dunk sparge with about 1.5 gal at mash out temps in a separate pot for 10-15 minutes, pull the bag and squeeze like hell. Then add any further drippings to the boil about halfway through.

3) triple crush at LHBS

4) get a mill

agreed. As far as biabrewer. info is concerned, I think it's pretty decent but a little set in its ways they insist that certain things are necessary for biab, like 90 min mash and 90 min boil , only full volume mash, etc. None of that is necessary at all, the majority of users here mash for 45-60, grind very fine, and do 60 min boils.

My advice for getting efficiency in biab,

1) Grind as fine as you can, and make sure your bag is good quality with a tight weave. Wilder sells great bags. Ask the lhbs what mill gap they're using, if they don't know, ask if they could measure and find out as it's in their best interest to provide good service to their customers rather than trying to milk them for another few lb of grains...

2) Use the proper Temps and water volumes, what software are you using? I'd recommend one of the following only: beersmith, the biabacus(setup takes a while until you get used to it), or my calculator at my sin and click calculator)

3)Stir the crop out of it with a whisk at dough in, pour the grains in slowly, and stir regularly (every 15 min) should gain you a couple points

4) when you pull the bag, stir the crop out of the grains.

5) sparge a bit, try 1-1.5, gallons.

Could you take a pic of the grain crush next time so we can try and take a look? That's the most likely culprit.
 
For a more comprehensive rundown of my answers you can see my BIAB setup in the thread below my sig.

Crush: Crush fine as this will allow more rapid and more complete wetting of the grains allowing very high mash efficiencies. One prior poster states that a fine crush is phooey yet immediately states they double mill. They are therefore using a fine crush. You can use a blender if you have one.

Volume of mash: Thinner mashes have been shown to allow higher efficiencies. It is not detrimental to the quality of the wort assuming pH is adjusted as needed. There is no direct benefit to reducing the mash volume. There are benefits if your equipment does not allow full volume mashing, of course.

Sparge or no-sparge. Most folk attest to a slight increase in efficiency with one. (Dunk or pour over can be used). The big benefit here is that corrections to a preboil volume can be made if you have undershot. Some folks deliberately undershoot, allowing accurate pour over spare to preboil volume. Makes great sense.

pH adjustment: Thinner mash and lighter grain bills will likely benefit from some degree of mash acidification with lactic acid or acidulated malt. This requires knowing what's in the water (minerals). a ward labs report or building your own water are of use here. I would not do any changes without knowing the water profile or building your own water with RO water.

I use a mash out (168F for 5 mins) and stir twice during my 30-60 minute mashes, stir thoroughly prior to pulling the bag, squeeze the heck out of it and have very low grain absorption.

No spills, no boil overs, minimal trub loss all allow for good efficiency and consistency.

Also a recent article BIAB like a BOSS covers some questions you might have. (Shameless plug):D
 
Last edited:
Can you post:
  1. Your recipe
  2. Mash temps & times
  3. All volumes including strike, sparge, pre-boil, post-boil, and to fermenter
  4. All gravity readings (pre-boil, post-boil, others)
  5. Water report, if you have it, and any water additions
  6. Mash pH, if you have it
Questions:
  1. Did you double check your grain weights?
  2. Have you calibrated your thermometers & hydrometer?
  3. Did you do an iodine conversion test on the mash?
  4. Did you cool the wort before taking gravity readings?
  5. How did you determine your volumes, and were the methods calibrated?
With the above information, we can double check your efficiency, and also do all of the different efficiencies described here. By isolating the low efficiency area of your brewery, we can help pinpoint the problem.

But assuming your efficiency numbers are correct and not knowing all of the above, BIAB efficiency problems seem to be most often due to problems with the conversion.

Brew on :mug:
 
Fine crush and recirculating made the biggest gains for me. I do no sparge and get 80% consistently. I think I crush @ .035 or if I remember correctly. One brew my mill was acting up and the crush wasn't good and it was back in the 60s so I know it makes a difference.
 
OP what temp and how long are you mashing?
Also how busy is your LHBS on average? Stale/old or improperly stored grains can cause mash efficiency issues.

It varies. Let's see, from most recent to least:

Kolsch: 150 for 30 minutes. Checked conversion with iodine.
IPA: 152 for 75 minutes.
Witbier: 148 for 90 minutes.

Regarding the grain at my LHBS, I believe it is fresh. It's Adventures in Homebrewing in Ann Arbor, and they do a pretty roaring business. More importantly, my friend that buys his grain there and does traditional 3 vessel doesn't have efficiency problems.

Make sure your thermometer is accurate. This is huge.

I have the Thermoworks Mini Handheld Type K with the wire probe with teflon tip. It read true in boiling and ice water, so I think it's good.

How long to you stir at dough-in? In addition to the useful things already mentioned, that can have an impact on your efficiency.

I try to give it a good stir so the water mixes with the grain. Maybe 1-2 minutes of stirring before I put the lid on and insulate with a sleeping bag. Traditionally I would then stir again every 30 minutes, but this time I checked conversion at 30 minutes and it was done, so I gave it a stir and pulled the bag out.

This may sound really dumb... I don't BIAB, but I had lousy efficiency until I stirred the grain every 15 minutes. Even though you have a bag and squeeze, I imagine stirring is still important. Do you do that?

See above.

Which may lead to speculation that perhaps the mash temp is too low. I seem to have noticed this first hand on my BIAB system. Mashing at 154 on my BIAB system is like mashing at 150 on my old batch spare system.

My question for Calypso is are you doing anything with your water? What kind are you using(tap water, Reverse Osmosis, Distilled), any addition or treatments?

So, I use my tap water. I had it analyzed, which I'll include here:

pH: 7.5
Na: 6
K: <1
Ca: 28
Mg: 8
Total Hardness: 103
NO3: 0.3
SO4: 8
Cl: 10
CO3: <1
HCO3: 105
Total Alkalinity: 86
P: 2.23
Fe: <0.01

I've started using Bru'n Water to calculate modifications to composition and pH. In this case, I added 2 grams of Calcium Chloride in the water and 5 ounces of Acid Malt in my grain bill.

agreed. As far as biabrewer. info is concerned, I think it's pretty decent but a little set in its ways they insist that certain things are necessary for biab, like 90 min mash and 90 min boil , only full volume mash, etc. None of that is necessary at all, the majority of users here mash for 45-60, grind very fine, and do 60 min boils.

My advice for getting efficiency in biab,

1) Grind as fine as you can, and make sure your bag is good quality with a tight weave. Wilder sells great bags. Ask the lhbs what mill gap they're using, if they don't know, ask if they could measure and find out as it's in their best interest to provide good service to their customers rather than trying to milk them for another few lb of grains...

2) Use the proper Temps and water volumes, what software are you using? I'd recommend one of the following only: beersmith, the biabacus(setup takes a while until you get used to it), or my calculator at my sin and click calculator)

3)Stir the crop out of it with a whisk at dough in, pour the grains in slowly, and stir regularly (every 15 min) should gain you a couple points

4) when you pull the bag, stir the crop out of the grains.

5) sparge a bit, try 1-1.5, gallons.

Could you take a pic of the grain crush next time so we can try and take a look? That's the most likely culprit.

1) Yeah, I got a custom made bag from someone on here. It's great. I'll ask about the mill gap next time I'm in there.

2) I use BeerSmith for almost everything. The only other tools I use are the carbonation tool from Northern Brewer and the strike temp calculator at http://simplebiabcalculator.com/

3, 4) I'll try that. You think I'm getting balls of grain that aren't mixing?

5) I tried sparging with my first couple BIAB outings and found it to be a major hassle. After doing some reading, I decided to move to full volume boils, and am happy with the process. I know there are people out there that get good efficiency with full volume boils, so I'd rather not give up on it just yet.

I have a bag of crushed grains at home, I'll try to remember to post a picture tonight.
 
Can you post:
  1. Your recipe
  2. Mash temps & times
  3. All volumes including strike, sparge, pre-boil, post-boil, and to fermenter
  4. All gravity readings (pre-boil, post-boil, others)
  5. Water report, if you have it, and any water additions
  6. Mash pH, if you have it
Questions:
  1. Did you double check your grain weights?
  2. Have you calibrated your thermometers & hydrometer?
  3. Did you do an iodine conversion test on the mash?
  4. Did you cool the wort before taking gravity readings?
  5. How did you determine your volumes, and were the methods calibrated?
With the above information, we can double check your efficiency, and also do all of the different efficiencies described here. By isolating the low efficiency area of your brewery, we can help pinpoint the problem.

But assuming your efficiency numbers are correct and not knowing all of the above, BIAB efficiency problems seem to be most often due to problems with the conversion.

Brew on :mug:

Sure. I'll post the most recent one.

8 pounds German Pilsner
8 ounces Vienna Malt
5 ounces Acid Malt

Grains are double crushed. Mash in at 154F. Stir. Cover. Temp is 151 (target was 150). Let sit for 30 minutes. Uncover, stir. Check for conversion with iodine. Looks good. Temp is 150.1. Raise bag and let drain until it's slowed down, transfer to bucket with colander. Let sit. Fire up main pot to begin raising to boil. Once draining is done, squeeze, add wort from bucket back to main pot.

Full water volume: 7.25 gallons
Pre-boil volume: 6.75 gallons
Post-boil volume (but not cooled): 6 gallons
Into fermenter: 5.25 gallons

Pre-boil gravity: 1.030
Post-boil gravity (including 1 pound extract addition): 1.040

Samples were cooled to 60F (+0.00) before measurement.

Water report:
pH: 7.5
Na: 6
K: <1
Ca: 28
Mg: 8
Total Hardness: 103
NO3: 0.3
SO4: 8
Cl: 10
CO3: <1
HCO3: 105
Total Alkalinity: 86
P: 2.23
Fe: <0.01

I added 2 grams of CaCl.

I don't have the mash pH.

Answer to questions:
  1. Yeah, two different scales.
  2. I have calibrated my thermometer. I checked my hydrometer in distilled water.
  3. I did. My only concern here is that I didn't stir. I've read, since yesterday, that it's possible for the iodine to stick to the surface of the wort without breaking the surface tension, resulting in no mixture. I don't think this happened, however, and I did two separate iodine tests.
  4. Yes, to the 0.00 point for my hydrometer (60F).
  5. It's not very fancy. I measured out half gallon increments into my brew pot, then put markings along the length of my paddle to indicate 0.5 - 9.0 gallons.
 
Preboil gravity is very very low. This points to a mash problem. poor crush most likely. Mash pH would also be worth looking at. What was it measured at and how?

You only went from 1.03 to 1.04 following the boil and addition of a pound of extract. This seems odd.
 
I try to give it a good stir so the water mixes with the grain. Maybe 1-2 minutes of stirring before I put the lid on and insulate with a sleeping bag. Traditionally I would then stir again every 30 minutes, but this time I checked conversion at 30 minutes and it was done, so I gave it a stir and pulled the bag out.

When you did the iodine test did you only test the wort or did you also test the grain? The grain may have had unconverted starch yet if the crush was not fine enough for the short mash. Make sure to do an iodine test with mostly grain next time and if it doesn't show full conversion, let it sit longer.
 
When you did the iodine test did you only test the wort or did you also test the grain? The grain may have had unconverted starch yet if the crush was not fine enough for the short mash. Make sure to do an iodine test with mostly grain next time and if it doesn't show full conversion, let it sit longer.

Just wort. I've read in multiple places that grain in the sample can yield false positives?
 
I keep going back to the fact that he's only mashing about 30 minutes. I give it the full 1 hour & get higher gravities than he is.
 
I highly doubt Adventures in Homebrewing has their mill set so wide to give a poor crush even with double milling.

Wondering if you got dough balls that are staying intact at the bottom or sugars are stratified when you grab your test sample.

EDIT: Next brew take multiple gravity readings (30 or 45, 60, 90:confused: ) through the mash and see when the gravity stops climbing.
 
Preboil gravity is very very low. This points to a mash problem. poor crush most likely. Mash pH would also be worth looking at. What was it measured at and how?

You only went from 1.03 to 1.04 following the boil and addition of a pound of extract. This seems odd.

According to BeerSmith, 1 pound of extract only increases the gravity by .006.

I have a pH meter, but I haven't gotten in the habit of using it during mashing yet. This is a pretty light beer, though. The target pre-boil gravity was 1.032.

EDIT: Note, that was with a brewhouse efficiency estimate of 65%, which I still missed. Even if I'd hit my target, I'd still be looking at ways to improve that.

EDIT2: Another note, my efficiency was lousy even with longer mash times. I went from 90, to 75, to 30, and my efficiency has stayed right around 60%.
 
I highly doubt Adventures in Homebrewing has their mill set so wide to give a poor crush even with double milling.

Wondering if you got dough balls that are staying intact at the bottom or sugars are stratified when you grab your test sample.

Definitely could be. I'll look at ways to stir my grain better, like maybe a long handled whisk as someone suggested.
 
Here's what I do with my BIAB and I always get low to mid 80 eff. I have a simple setup where my mash tun (SS pot) can only hold 6 lbs of grain. First I mash in with a 1.5 water/grain ratio. Since I need to use 3-4 lbs of DME I usually aim low with my mash temp (around 150º) to keep residual sweetness lower.

This next step is what you're missing and may help you a lot.

After 60 minutes I drain the bag over my larger brew pot, when it's done draining I do a dunk sparge with the same water to grain ratio for 10 minutes (dunking periodically) with 170º fresh water.

Give it a try next time, only takes 10 minutes...

Anyway, that's my 2¢
 
I do a 10 minute dunk sparge myself, aka batch sparge in BS2, etc. I do it in a couple different size kettles, depending on the size of the partial mash. But generally, 1 1/4 to 1/ 1/2 gallons spring water @ 168-170F for that 10 minutes, stirring it at the beginning.
 
It varies. Let's see, from most recent to least:

Kolsch: 150 for 30 minutes. Checked conversion with iodine.
IPA: 152 for 75 minutes.
Witbier: 148 for 90 minutes.

Regarding the grain at my LHBS, I believe it is fresh. It's Adventures in Homebrewing in Ann Arbor, and they do a pretty roaring business. More importantly, my friend that buys his grain there and does traditional 3 vessel doesn't have efficiency problems.



I have the Thermoworks Mini Handheld Type K with the wire probe with teflon tip. It read true in boiling and ice water, so I think it's good.



I try to give it a good stir so the water mixes with the grain. Maybe 1-2 minutes of stirring before I put the lid on and insulate with a sleeping bag. Traditionally I would then stir again every 30 minutes, but this time I checked conversion at 30 minutes and it was done, so I gave it a stir and pulled the bag out.



See above.



So, I use my tap water. I had it analyzed, which I'll include here:

pH: 7.5
Na: 6
K: <1
Ca: 28
Mg: 8
Total Hardness: 103
NO3: 0.3
SO4: 8
Cl: 10
CO3: <1
HCO3: 105
Total Alkalinity: 86
P: 2.23
Fe: <0.01

I've started using Bru'n Water to calculate modifications to composition and pH. In this case, I added 2 grams of Calcium Chloride in the water and 5 ounces of Acid Malt in my grain bill.



1) Yeah, I got a custom made bag from someone on here. It's great. I'll ask about the mill gap next time I'm in there.

2) I use BeerSmith for almost everything. The only other tools I use are the carbonation tool from Northern Brewer and the strike temp calculator at http://simplebiabcalculator.com/

3, 4) I'll try that. You think I'm getting balls of grain that aren't mixing?

5) I tried sparging with my first couple BIAB outings and found it to be a major hassle. After doing some reading, I decided to move to full volume boils, and am happy with the process. I know there are people out there that get good efficiency with full volume boils, so I'd rather not give up on it just yet.

I have a bag of crushed grains at home, I'll try to remember to post a picture tonight.

I'm not too sure man, It really looks like you're trying everything. Let us have a pic, also get out of simplebiab calculator, it's bad and too simple. Either go to mine at pricelessbrewing.github.io/biabcalc, or use the one at biabcalculator.com (almost as good, but doesn't have a couple features).

I've been to AiH as well, both sites, and I've never had anything milled by them though I'm sure they have it set to the right gap for traditional 3v setups so you should be getting around 70. Thermoworks is a good thermoemters too so you should be fine there.

If you're nearby, I would be done with meeting up on a brewday if you want another set of eyes to look over everything.
 
Just wort. I've read in multiple places that grain in the sample can yield false positives?

It can't indicate starch when there is no starch present. If it shows starch, you haven't gotten full conversion. Longer mashes or finer milling are what is needed if it shows starch.
 
I keep going back to the fact that he's only mashing about 30 minutes. I give it the full 1 hour & get higher gravities than he is.

I agree. Yes, BIABrewer.info does insist on 90 min mashes and boils, but a 90 min mash vs a 60 min mash is a useful technique based on how you want your beer to finish out. I only do 90 boils for pilsner malt. A 30 min mash is awful short.

"Crush: Crush fine as this will allow more rapid and more complete wetting of the grains allowing very high mash efficiencies. One prior poster states that a fine crush is phooey yet immediately states they double mill. They are therefore using a fine crush. You can use a blender if you have one."

Nice try. Double or triple milling doesn't give you a finer crush. It makes sure that all your grains are crushed open. A good analogy I've heard is a grain is like a packed suitcase. All you need to do is crack open the suitcase and expose the material inside. It is unnecessary to take what's inside and grind it up too. The double crush makes sure that every suitcase got popped open. To get a finer crush, you would need to decrease the space between the rollers.

I would only use a blender if I was making mudslides while brewing;)

I find if I follow the amounts in the BIABacus closely and use good brewing practices that I learned at BIABrewer (and from here) I hit my expected OG 99% of the time. If my actual OG is too high, I add back some water. If it is too low, then I drink a weaker beer. But after some practice, you'll get to know how to improve your technique and soon you'll start nailing your expected OG's. Have fun! Don't over complicate it. It's beer!
 
Well lucky you, landing on this hobby. Did you know that homebrewing is a sport of upgrades? I got into it because I thought I could make beer cheaper:cross:

Hah! I at least didn't have that delusion. But I do seem to be drawn to hobbies where I can spend tons of money on minor upgrades. Like photography!
 
Sure. I'll post the most recent one.

8 pounds German Pilsner
8 ounces Vienna Malt
5 ounces Acid Malt

Grains are double crushed. Mash in at 154F. Stir. Cover. Temp is 151 (target was 150). Let sit for 30 minutes. Uncover, stir. Check for conversion with iodine. Looks good. Temp is 150.1. Raise bag and let drain until it's slowed down, transfer to bucket with colander. Let sit. Fire up main pot to begin raising to boil. Once draining is done, squeeze, add wort from bucket back to main pot.

Full water volume: 7.25 gallons
Pre-boil volume: 6.75 gallons
Post-boil volume (but not cooled): 6 gallons
Into fermenter: 5.25 gallons

Pre-boil gravity: 1.030
Post-boil gravity (including 1 pound extract addition): 1.040

Samples were cooled to 60F (+0.00) before measurement.

Water report:
pH: 7.5
Na: 6
K: <1
Ca: 28
Mg: 8
Total Hardness: 103
NO3: 0.3
SO4: 8
Cl: 10
CO3: <1
HCO3: 105
Total Alkalinity: 86
P: 2.23
Fe: <0.01

I added 2 grams of CaCl.

I don't have the mash pH.

Answer to questions:
  1. Yeah, two different scales.
  2. I have calibrated my thermometer. I checked my hydrometer in distilled water.
  3. I did. My only concern here is that I didn't stir. I've read, since yesterday, that it's possible for the iodine to stick to the surface of the wort without breaking the surface tension, resulting in no mixture. I don't think this happened, however, and I did two separate iodine tests.
  4. Yes, to the 0.00 point for my hydrometer (60F).
  5. It's not very fancy. I measured out half gallon increments into my brew pot, then put markings along the length of my paddle to indicate 0.5 - 9.0 gallons.

I ran you pre-boil volumes (corrected to RT) and gravity against your grain bill and got a 61% mash efficiency. So, low efficiency is confirmed.

I also put your water report, water additions and grain bill (including acid malt) into Bru'nWater, and got an estimated room temp mash pH of 5.7. This is a bit too high if it is what you actually got. You want to target for something closer to 5.4. I'm not an expert in this area, so don't know how much that may have affected your eff.

Big thing seems to be the 30 min mash. Unless you crush fine, you need a longer mash to let diffusion do its work. With larger particles, diffusion limited processes take longer to complete. An iodine test on just the wort is likely to give a false sense of security. The starch in the wort gets converted very fast, but that tells you nothing about the starch remaining in the grain particles. The vast majority of the unconverted starch will be in the grain particles.

My best guess is that you did not give the mash enough time to actually reach completion, and that a high mash pH aggravated that problem. My recommendations are:
  1. Crush finer if possible
  2. Stir more at mash in (really look for dough balls, even little ones), and at end of mash. Additional stirring every 15 min during mash would also likely help
  3. Add more acid, either as acid malt or liquid lactic or phosphoric acid
  4. Monitor the wort pH (cool to RT for measurement)
  5. Include grain particles in the iodine test
  6. Monitor the wort SG during the mash, and only pull the bag (or mash out) when the mash is very close to 100% conversion (see link in previous post.)
Brew on :mug:
 
My recommendations are:
  1. Crush finer if possible
  2. Stir more at mash in (really look for dough balls, even little ones), and at end of mash. Additional stirring every 15 min during mash would also likely help
  3. Add more acid, either as acid malt or liquid lactic or phosphoric acid
  4. Monitor the wort pH (cool to RT for measurement)
  5. Include grain particles in the iodine test
  6. Monitor the wort SG during the mash, and only pull the bag (or mash out) when the mash is very close to 100% conversion (see link in previous post.)
Brew on :mug:

Great recommendations, thank you! I'll try them all.

It's funny, I thought I had gotten the pH to 5.45, but I just reran the Bru'n sheet and got the same 5.7 as you. I wonder where I messed up!
 

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