Mash efficiency problems - HELP!

[robcoombs]

   I've been having a lot of problems with my mash efficiency since I started brewing AG in May. At first I chalked it up to inexperience but after this many months and brews under my belt it has become very frustrating. I've only started measuring the pre-boil gravity for my last four batches but my OG have always been 3-7 points low. Mind you 3 points is not a huge deal, but my pre boil gravities are consistently 20-24 points low! So I usually crank the heat on the propane to boil off as much as possible so that my OG lands somewhere close to where it needs to be. Generally it's 7 points low, I've only come within 3 points once. Anyway, I know I get close to my expected OG in the end but I'm losing more wort than I should be boiling this way. So I'm obviously doing something very wrong but have no idea what. I generally come within a degree or two of hitting my mash temp.

   I've read countless articles online about mash efficiency and even a book or two and tried everything I can find to get my pre boil gravity up but with no luck at all. Here's what I've tried so far.

-I bought a new hydrometer (long shot I know but this made no difference)
-Measured the sparge and strike water temperature with an external thermometer as well as the kettle thermometer to make sure they are consistent (they are)
-Narrowed the gap in my BC to 0.34
-Tried a very slow batch sparge (45-60 minutes, no improvement)


  This evening I brewed a chocolate espresso oatmeal stout. I hit my mash temperature (156) perfectly. I let it rest for 60 minutes and measured the temperature at the end of the mash. I had only lost 0.6C over the hour. I then sparged over about 15 minutes and added the strike water at 170. I let that sit for about another 10 minutes before finishing the sparge and getting to my pre boil volume. I gave the wort a gentle stir to ensure both runnings were mixed well and measured the SG. It was 22 points low!

   At this point I am incredibly frustrated! I have run out of ideas to try to boost my efficiency. I'm hoping someone here can suggest anything for me to try. I'm open to any ideas, anything at all.

[blisster]

Wow.. I'm really not sure.

Do you ever see any dry dough balls when you dump your spent grains? Long shot, I know, but worth asking...

Water PH issue maybe?

What water/grain ratio are you using in your mash?  I believe most use around 1.25 quarts/pound (2.608 l/kg).

Do you have the detailed recipe with grain bill, water volumes, temps, etc?  If you are using the cylinder type mashtun cooler you have a very similar setup than mine... I'm curious to see what estimated numbers I would see using my BeerSmith equipment profile.  I usually get low-mid 70's brewhouse efficiency with my setup.. Give or take a few points depending on what the grain bill is or if I mess-up on something.

You could always try borrowing another mill or running your grains through twice to see if that helps... My OBK mill has a slight warp in one of the rollers, I'm sure that can me a difference..

I'm not an expert by any means, these are all guesses, lol   

[Roger]

What kind of mash tun are you using? I attribute my 80% + efficiency to my bottom drain set up. I get every last drop of wort before sparging and after.

[Al-Loves-Wine]

Two things that seriously affect my efficiency, crush, and not completely draining my mash tun before I start the sparge. Both in my experience have made my brewhouse efficiency very poor. Every once in awhile you are just gonna have a bad brew day, but definitely shouldn't see it every time ya brew. Big beers yes, 60% is usually considered good, but lighter you can expect it to be +70.

I'd say make sure you are crushing fine, and I mean crush till you're scared of getting to fine. Don't run your drill wide open, if you can hold it consistent 300ish rpm you will pinch your husk a bit better leaving it in tact squishing out that sweet kernel and make the lauter much smoother. Going way to fast I find pulverizes the husk and makes washing your grain bed that much more difficult when its packed in tight. Also what Roger just said, really really wait out the first runnings before you start sparge, minimal to no drip left in it. Draining your mash tun out of every last possible drip makes big gains. Long wait is really worth it for increased efficiency. Try throwing in a pound of rice hulls as well would be worth a shot if your crush is beyond pulverized.

Something else that I thought of, try extending you mash time to 75 minutes as well, just to ensure you are getting full conversion. Myself 75 is a minimum for me, rarely do 60 unless I'm looking for some residual sweetness. I've found beersmiths strike volume to be spot on as well for style, its helped me a lot.

[blisster]

Myself 75 is a minimum for me, rarely do 60 unless I'm looking for some residual sweetness.

dito

[robcoombs]

Myself 75 is a minimum for me, rarely do 60 unless I'm looking for some residual sweetness.

dito

I've tried doing a 90 minute mash with no improvement

[robcoombs]

What kind of mash tun are you using? I attribute my 80% + efficiency to my bottom drain set up. I get every last drop of wort before sparging and after.

I used a rectangular Coleman cooler for my mashtun on this one. I let it drain nearly completely, but I don't think I have ever drained every single drop from the cooler before adding the strike water.

[jamie_savoie]

I'd say make sure you are crushing fine, and I mean crush till you're scared of getting to fine. Don't run your drill wide open, if you can hold it consistent 300ish rpm you will pinch your husk a bit better leaving it in tact squishing out that sweet kernel and make the lauter much smoother. Going way to fast I find pulverizes the husk and makes washing your grain bed that much more difficult when its packed in tight.

IMO this will make the most improvement on your efficiency.  If you're afraid you'll have a stuck sparge add some rice hull

[pliny]

I've only started measuring the pre-boil gravity for my last four batches but my OG have always been 3-7 points low. Mind you 3 points is not a huge deal, but my pre boil gravities are consistently 20-24 points low!

I don't know your setup, your methods and didn't see your recipe so this would make it difficult to pinpoint but I have a few questions.
With regards to your pre-boil gravity; are you compensating for temperature adjustment? If the wort you're measuring is warmer than 68F (20C) then your reading will be off. Ex: if you take a reading of your pre-boil, and it reads 1.040 and the temperature of your wort is 140F (60C) then your pre-boil gravity is actually 1.053.

Do you use software? If yes, do you have an equipment profile setup? If not, not big deal.
I used to fuss a bit about pre-boil gravity, get all worked up and worried during my brew session. I don't keep track of it anymore.

I think you were making a stout but is 156F a bit high for mash temp? Maybe it's just me.

Oh and another thing; do you batch sparge? I mentioned this countless times but I pretty much follow what this guys does: http://hbd.org/cascade/dennybrew/
During the 60 minute mash, I give a good stir every 15 minutes. I've read somewhere that you don't have to do this but I find this helps for me. It doesn't bother the grain bed. I also give it a vigourous stir when I add the sparge water (the second water addition - for the second runnings).

[robcoombs]

I'd say make sure you are crushing fine, and I mean crush till you're scared of getting to fine. Don't run your drill wide open, if you can hold it consistent 300ish rpm you will pinch your husk a bit better leaving it in tact squishing out that sweet kernel and make the lauter much smoother. Going way to fast I find pulverizes the husk and makes washing your grain bed that much more difficult when its packed in tight.

IMO this will make the most improvement on your efficiency.  If you're afraid you'll have a stuck sparge add some rice hull

I will narrow the BC width even more. I generally use 1/2lb of rice hulls for most brews, including the one last night.

[robcoombs]

Wow.. I'm really not sure.

Do you ever see any dry dough balls when you dump your spent grains? Long shot, I know, but worth asking...

Water PH issue maybe?

What water/grain ratio are you using in your mash?  I believe most use around 1.25 quarts/pound (2.608 l/kg).

Do you have the detailed recipe with grain bill, water volumes, temps, etc?  If you are using the cylinder type mashtun cooler you have a very similar setup than mine... I'm curious to see what estimated numbers I would see using my BeerSmith equipment profile.  I usually get low-mid 70's brewhouse efficiency with my setup.. Give or take a few points depending on what the grain bill is or if I mess-up on something.

You could always try borrowing another mill or running your grains through twice to see if that helps... My OBK mill has a slight warp in one of the rollers, I'm sure that can me a difference..

I'm not an expert by any means, these are all guesses, lol   

I always go through the mash really well to ensure there are never any dough balls that I've noticed.

I haven't measured the ph of my water in a very long time. I will have to try that this weekend.

I use beersmith so I believe my grain/water ratio changes depending if I want light vs medium vs full body beer.

[robcoombs]

Two things that seriously affect my efficiency, crush, and not completely draining my mash tun before I start the sparge. Both in my experience have made my brewhouse efficiency very poor. Every once in awhile you are just gonna have a bad brew day, but definitely shouldn't see it every time ya brew. Big beers yes, 60% is usually considered good, but lighter you can expect it to be +70.

I'd say make sure you are crushing fine, and I mean crush till you're scared of getting to fine. Don't run your drill wide open, if you can hold it consistent 300ish rpm you will pinch your husk a bit better leaving it in tact squishing out that sweet kernel and make the lauter much smoother. Going way to fast I find pulverizes the husk and makes washing your grain bed that much more difficult when its packed in tight. Also what Roger just said, really really wait out the first runnings before you start sparge, minimal to no drip left in it. Draining your mash tun out of every last possible drip makes big gains. Long wait is really worth it for increased efficiency. Try throwing in a pound of rice hulls as well would be worth a shot if your crush is beyond pulverized.

Something else that I thought of, try extending you mash time to 75 minutes as well, just to ensure you are getting full conversion. Myself 75 is a minimum for me, rarely do 60 unless I'm looking for some residual sweetness. I've found beersmiths strike volume to be spot on as well for style, its helped me a lot.

I will try narrowing the gap in my BC even more and get every last drop out before adding the strike water next time.

[robcoombs]

I've only started measuring the pre-boil gravity for my last four batches but my OG have always been 3-7 points low. Mind you 3 points is not a huge deal, but my pre boil gravities are consistently 20-24 points low!

I don't know your setup, your methods and didn't see your recipe so this would make it difficult to pinpoint but I have a few questions.
With regards to your pre-boil gravity; are you compensating for temperature adjustment? If the wort you're measuring is warmer than 68F (20C) then your reading will be off. Ex: if you take a reading of your pre-boil, and it reads 1.040 and the temperature of your wort is 140F (60C) then your pre-boil gravity is actually 1.053.

Do you use software? If yes, do you have an equipment profile setup? If not, not big deal.
I used to fuss a bit about pre-boil gravity, get all worked up and worried during my brew session. I don't keep track of it anymore.

I think you were making a stout but is 156F a bit high for mash temp? Maybe it's just me.

Oh and another thing; do you batch sparge? I mentioned this countless times but I pretty much follow what this guys does: http://hbd.org/cascade/dennybrew/
During the 60 minute mash, I give a good stir every 15 minutes. I've read somewhere that you don't have to do this but I find this helps for me. It doesn't bother the grain bed. I also give it a vigourous stir when I add the sparge water (the second water addition - for the second runnings).

I will post the recipe as soon as I get home this evening so everyone can take a look at it.

I use Beersmith and yes I have an equipment profile set up. I had wanted a full body for this stout so BS recommended the 156F, the last stout I brewed had a mash temp of 150 and I found it lacking in body.

I do batch sparge but have never stirred during the mash rest, I will try that next time as well. I always give the grain a good stir after adding the water for second runnings and let it sit for anotehr 10 minutes before laudering those runnings.

[robcoombs]

I don't know your setup, your methods and didn't see your recipe so this would make it difficult to pinpoint but I have a few questions.
With regards to your pre-boil gravity; are you compensating for temperature adjustment? If the wort you're measuring is warmer than 68F (20C) then your reading will be off. Ex: if you take a reading of your pre-boil, and it reads 1.040 and the temperature of your wort is 140F (60C) then your pre-boil gravity is actually 1.053.

I actually had no idea I had to compensate for temperature in pre-boil gravity measurement. I always measure it above 68F  something else for me to try

[pliny]

About compensating for temperature, you can either try to cool a small sample of your wort to about 68F or you can take a temp reading and do a conversion.

I do batch sparge but have never stirred during the mash rest, I will try that next time as well. I always give the grain a good stir after adding the water for second runnings and let it sit for anotehr 10 minutes before laudering those runnings.

Good, stir the heck out of it (in my opinion). But I still try to make sure that my mash temp is maintained during your mash. Of course opening the lid will make you lose some heat but opening it two or three times for 10 seconds during a 1 hour mash hopefully won't hurt your mash conversion. Go with what works for you. Like I said, some folks don't believe in in stirring because they say that the starches know what to do and don't need to be stirred. I've tried not stirring in the past and my temperature was fine but my efficiency wasn't. Could've been a coincidence or not.
I let it sit for about 10 seconds after the stir. The time that it takes for my stir stick to put on the counter and open the valve.