[Pope of Dope]

Still having efficiency problems with my BIAB set up. These are consistently in the range of 60% and even 50%. There was a time when I was getting 75%, but all of a sudden this. 

The only difference is the water. I used to use filtered tap, and now I'm building up from RO. The beer tastes good, better than tap, so I must be doing something right, pH at 5.3, and this is the only factor that is different.

I also understand that efficiency is a common problem with the BIAB brewing method, though I have done it for many years with no problems in the past. The previous/successful brews where I got a 75% were likely brewed with a mash pH somewhere around 6. And, though out of range, I presume the higher pH is better at extracting those sugars.

To state the obvious factors: grain crush is what it is, I don't have my own mill, but crush hasn't changed from the past, always done at the same LHBS mill. Mash temps are held well, thermometer has been calibrated, I've gone as low at 149 and as high at 154 to try differing temps - results are the same. I've tried stirring, squeezing, not squeezing (squeezing bag gave me a couple more gravity points but efficiency still suffered). Mash out and no mash out.

To remedy, the only thing I can think to do is increase mash time from 60mns to 90msn. Maybe it takes the grain longer given the lower pH and that it is in a voil bag versus the traditional method. What confuses me is to hear of some doing a 40 min mash and getting good results, but as they say, maybe it's something in the water. I have asked about this matter before so sorry about the repetition, but any further thoughts would be appreciated.

[JT]

Put it in perspective - especially if your beer is tasting good.  Lower you efficiency expectations and determine how much more you are spending.  My guess: between $1.50 and $3.00 per 5 gallon batch. 

[Robert]

You say the grain crush is the same because the same shop is milling it.  Are you sure their mill hasn't gone out of adjustment, or been intentionally reset?  Talk to them, seems like a good place to start troubleshooting (the one factor you don't know for sure.) The pH you're getting now is far better for enzyme activity than before, that's not the problem.  And until you find the answer, enjoy some of that better tasting beer.  +1 on JT's comment.

[dmtaylor]

I'm with Robert.  The LHBS most likely changed the mill gap setting.  Try double-crushing if you haven't already, and eventually invest in your own mill and then never have this problem again.

[denny]

Yeah, I think do uble crushing is an easy way to start investigating.

[ynotbrusum]

The mill gap can slip over time, too, if it is an adjustable type.  The LHBS may not even be aware of it.  Bring a set of "feelers" with you on the next visit and see if they will set it to your desired gap.  IIRC I set mine at around .025 to .029, but I use a BIAB and rarely encounter any stuck sparge issues.

[reverseapachemaster]

I agree the shop mill is the likely culprit but in the event it isn't milling then your change in water profile is the second place I would look. You say the ph is 5.3 and used to be 6. How are you measuring this? Ph strips are not particularly reliable, especially if you measure hot liquids.

[Big Monk]

I agree the shop mill is the likely culprit but in the event it isn't milling then your change in water profile is the second place I would look. You say the ph is 5.3 and used to be 6. How are you measuring this? Ph strips are not particularly reliable, especially if you measure hot liquids.

Also, lower pH, especially in that range, should yield better conversion and thus better deficiency, not worse.

Troubleshooting would look something like this:

Bad Efficiency -> check factors affecting conversion (crush, pH, gelatinization temp, etc.) -> check factors affecting lautering (mixing, stirring, etc.)

[Robert]

The mill gap can slip over time, too, if it is an adjustable type.  The LHBS may not even be aware of it.  Bring a set of "feelers" with you on the next visit and see if they will set it to your desired gap.  IIRC I set mine at around .025 to .029, but I use a BIAB and rarely encounter any stuck sparge issues.

I have my gap at 0.030" (approximates ASBC coarse grind) and get over 90% brewhouse efficiency, with no runoff problems at all (fast and clear,) fly sparging with a false bottom.   So you could obviously go finer than that with a BIAB.  I do check the adjustment with my feeler gauges every few runs.  Every so often it needs readjustment, even with exponentially less use than a LHBS mill.

EDIT One trick to milling fine is to keep the rpm's down.  Milling slower will limit husk damage even with a narrow gap.  I guess that's another thing that's less relevant to BIABers.  But LHBS should slow their mills and they could tighten the gap for everybody.  <150 rpm is a good target.

[ynotbrusum]

I have the 180 RPM model from All American Aleworks and it works great (I start it up before adding grain at the tighter gap range of .025 - .029):

https://allamericanaleworks.com/product/grain-mill-motor-shaft-couplers-package/

I have found it to deliver quite solid performance for a direct drive with spider buna connection.

[BrewBama]

I have my gap at 0.030" (approximates ASBC coarse grind) and get over 90% brewhouse efficiency, with no runoff problems at all (fast and clear,) fly sparging with a false bottom.   So you could obviously go finer than that with a BIAB.  I do check the adjustment with my feeler gauges every few runs.  Every so often it needs readjustment, even with exponentially less use than a LHBS mill.

EDIT One trick to milling fine is to keep the rpm's down.  Milling slower will limit husk damage even with a narrow gap.  I guess that's another thing that's less relevant to BIABers.  But LHBS should slow their mills and they could tighten the gap for everybody.  <150 rpm is a good target.

Robert, I am curious how 0.030" approximates ASBC coarse grind (I assume no 14 sieve). I am thinking Darcy’s law and pH to increase my efficiency. Like mentioned above it’s probably only a pound or two of grain and gallon of water difference for a total of 5 bucks but I feel like it’s my job to try to increase efficiency.

I am using a drill for my JSP Malt Mill so I may employ a clamp to eliminate the variability between the mill and drill (aka my finger).


Sent from my iPad using Tapatalk

[Robert]

I have my gap at 0.030" (approximates ASBC coarse grind) and get over 90% brewhouse efficiency, with no runoff problems at all (fast and clear,) fly sparging with a false bottom.   So you could obviously go finer than that with a BIAB.  I do check the adjustment with my feeler gauges every few runs.  Every so often it needs readjustment, even with exponentially less use than a LHBS mill.

EDIT One trick to milling fine is to keep the rpm's down.  Milling slower will limit husk damage even with a narrow gap.  I guess that's another thing that's less relevant to BIABers.  But LHBS should slow their mills and they could tighten the gap for everybody.  <150 rpm is a good target.

Robert, I am curious how 0.030" approximates ASBC coarse grind (I assume no 14 sieve). I am thinking Darcy’s law and pH to increase my efficiency. Like mentioned above it’s probably only a pound or two of grain and gallon of water difference for a total of 5 bucks but I feel like it’s my job to try to increase efficiency.

I am using a drill for my JSP Malt Mill so I may employ a clamp to eliminate the variability between the mill and drill (aka my finger).


Sent from my iPad using Tapatalk

This is in Palmer and Kaminski, Water, p. 71, on trials on effects of gap on pH: "The 0.8 mm setting on a two roller mill is probably most similar to the American Society of Brewing Chemists (ASBC) coarse grind condition, which is determined not by roller spacing but by 75% of a malt sample remaining on a No. 30 sieve...."  That's where I got that,  0.8 mm is 0.032".  But that's not why I picked the setting.  LHBS owner said 0.030" was working for him, I tried it, I liked it, I stuck with it.

I too use a JSP with a drill.  If you come up with a mechanical improvement on the human finger, please post details and pics!

Aside: I'm just like you on feeling it's my "job" to try to increase efficiency.  But I just accidentally happened on this from George Fix today: "However, it is rare in brewing for efficiency and beer quality to be in harmony."  Guess we should relax now and then, and buy the extra malt.  Oh, who am I kidding? 

[hopfenundmalz]

I have my gap at 0.030" (approximates ASBC coarse grind) and get over 90% brewhouse efficiency, with no runoff problems at all (fast and clear,) fly sparging with a false bottom.   So you could obviously go finer than that with a BIAB.  I do check the adjustment with my feeler gauges every few runs.  Every so often it needs readjustment, even with exponentially less use than a LHBS mill.

EDIT One trick to milling fine is to keep the rpm's down.  Milling slower will limit husk damage even with a narrow gap.  I guess that's another thing that's less relevant to BIABers.  But LHBS should slow their mills and they could tighten the gap for everybody.  <150 rpm is a good target.

Robert, I am curious how 0.030" approximates ASBC coarse grind (I assume no 14 sieve). I am thinking Darcy’s law and pH to increase my efficiency. Like mentioned above it’s probably only a pound or two of grain and gallon of water difference for a total of 5 bucks but I feel like it’s my job to try to increase efficiency.

I am using a drill for my JSP Malt Mill so I may employ a clamp to eliminate the variability between the mill and drill (aka my finger).


Sent from my iPad using Tapatalk

This is in Palmer and Kaminski, Water, p. 71, on trials on effects of gap on pH: "The 0.8 mm setting on a two roller mill is probably most similar to the American Society of Brewing Chemists (ASBC) coarse grind condition, which is determined not by roller spacing but by 75% of a malt sample remaining on a No. 30 sieve...."  That's where I got that,  0.8 mm is 0.032".  But that's not why I picked the setting.  LHBS owner said 0.030" was working for him, I tried it, I liked it, I stuck with it.

I too use a JSP with a drill.  If you come up with a mechanical improvement on the human finger, please post details and pics!

Aside: I'm just like you on feeling it's my "job" to try to increase efficiency.  But I just accidentally happened on this from George Fix today: "However, it is rare in brewing for efficiency and beer quality to be in harmony."  Guess we should relax now and then, and buy the extra malt.  Oh, who am I kidding? 

As a homebrewer, I no longer chase efficiency. I am after better beer.

[Robert]

I'm actually getting a lot better about that the last couple of years. Mysterious changes in your efficiency -- where the OP started -- require some investigation.  But Jeff is right.  The baseline of your efficiency, as a homebrewer, is of no particular importance.  Whatever system gets you good beer at a level of effort you're happy with is fine, and you can buy extra grain etc for cheap, and without the problem of the accountants leaning on the head brewer to squeeze a few more pennies out of every truckload.

[ynotbrusum]

I make homebrew, so efficiency was left in the computer a few hundred batches ago...but if you like numbers, calculate away!  I just wouldn’t get terribly hung up on or terribly prideful about efficiency at the homebrew level.  It is somewhat interesting, but once you have your system dialed in, you can concentrate on flavor profile as the ultimate factor.  Cheers to you engineers, though!