Frustratingly Low Mash Efficiency

[ajm97210]

So I have done a lot of reading on increasing efficiency and all that and while I understand that efficiency isn't everything when it comes to homebrewing, having a roughly 50% efficiency can be quite annoying. I am going to present my last 2 batches to you guys in hopes that someone can help me troubleshoot this or give me some more specific advice on increasing my low efficiency. Let's begin...

I will start by saying that I take fairly detailed notes on all my brews but I do have some holes here and there, but not many. I use Beersmith as well as handwritten notes to get all my numbers and calculations.

My set-up:
5.5gal Batches (into fermenter)
8.26gal Pre-Boil
21.2% Evaporation rate
.75gal Loss to Chiller/Trub
Brewhouse Efficiency set at 63%

10gal Kettle
10gal Cooler Mash Tun
Hellfire Burner
Batch Sparging - usually 2 runnings

Case #1:
Double IPA
(info straight from Beersmith)

4g Gypsum
3g Epsom
2g Calcium Chloride

13.8lbs 2-row
1lbs Flaked Oat
1lbs Flaked Wheat
1lbs Victory
.75lbs Carapils
.75lbs Honey Malt

Hops/Yeast irrelevant

Est. Pre Boil Vol 7.95gal
Meas Pre Boil Vol 7.95gal
Est Pre Boil Gravity 1.059
Meas Pre Boil Gravity 1.047

Est Batch Size 5.25gal
Measured Batch Size 5.25gal
Est OG 1.088
Measured OG 1.060

Est Mash Eff 72%
Measured Mash Eff 56.9%
Est BH Eff 63%
Measured BH eff 48%

Case #2
Blonde Ale

5g Gypsum
4g Epsom
2g Calcium Chloride

10lbs 2 Row
1lbs Caramel 15L
.25 Munich

Hops/Yeast irrelevant

Est. Pre Boil Vol 8.21gal
Meas Pre Boil Vol 8.25gal
Est Pre Boil Gravity 1.036
Meas Pre Boil Gravity 1.029

Est Batch Size 5.5gal
Measured Batch Size 5.5gal
Est OG 1.047
Measured OG 1.040

Est Mash Eff 71.6%
Measured Mash Eff 58.1%
Est BH Eff 63%
Measured BH eff 53.4%

After the DIPA I figured my gravity issue was due to all the flaked grains that I added without any 6 Row. The more recent blonde ale I decided to try out a smaller grain bill to see if I could get it more in the ball park, but obviously to my surprise I still wasn't even close. When I was collecting my grist for my blonde I did notice that the crush wasn't all that great so next time I will try to run it through the mill at my LHBS twice to see if that makes a difference. Another thought I had was in regards to mash pH, I do some rough water calculations using a water report for my area and an online water calculator but other than that I don't have a pH meter currently for taking readings.

Since getting the Hellfire and my new mash tun I had to retune my brewhouse numbers but I have done that over the last 5 batches I've made and feel comfortable with my volumes and such. I am using a refractometer to take all my readings during my brew, which I have calibrated and recalibrated just to make sure it was correct, as well as a hydrometer to double check my readings.

As I previously stated, obviously efficiency isn't everything but when I am not getting the conversion I want, or even remotely close, it get's rather irritating being 10 points shy of where I want to be.

Does anyone have any ideas or suggestions on how I could remedy this? Or at least where to start?
My only idea currently is to mill my grains twice.

 

[EcuPirate07]

Are you milling your grains or LHB? How long are you mashing? Are you sure conversion is done? Are you batch or fly sparging. What's your process? If you are hitting your water calculations but not your gravity I would assume you are not converting sugars well which affects your brew house eff.

 

[ajm97210]

Are you milling your grains or LHB? How long are you mashing? Are you sure conversion is done? Are you batch or fly sparging. What's your process? If you are hitting your water calculations but not your gravity I would assume you are not converting sugars well.

I am batch sparging, I have done it in 2 and 3 batches.
I mashed for 60min in the DIPA case and 90min in the Blonde case.
I am milling at my LHBS so I don't have control over the crush but I could run it through a 2nd time if I wanted.
As far as conversion goes, no I am not sure it's done but it sure sounds like it isn't.

 

[BrewievilleKy]

Try upping your mash temp by a few degrees and try a slower steady grain rinse. Also unless you think its really a milling issue try upping your grain bill by 2% to make up for the inefficiency. You sound like you do alot of numbers so try to have a little fun in there too. Cheers and hope I could help.

 

[trav77]

Sounds like a crush issue to me. Try double crushing next time. Giving the Nash a stir from time to time will help as well.

 

[trav77]

Also while stirring the Nash you can stir the mash.

Stupid autocorrect.

 

[kh54s10]

My guess is grain crush, but your boil off rate seems excessively high. It should not make much difference on your efficiency if you are ending up with the right volume into the fermenter but I would lower the heat. You will have to adjust your preboil volume if you do though so maybe get the efficiency under control then work on the boil off rate.

BTW, I don't think flaked grains and 6 row have much to do with things. I have used flaked grains but I have never used 6 row.

Either double crush or get yourself a mill. I am 6+ years into brewing and use a $20 corona style mill. I get about 70% Satisfied with that so I have not worked on increasing efficiency.

 

[DatsyukianDeke]

In Russia, The Nash stirs you!!

 

[ajm97210]

My guess is grain crush, but your boil off rate seems excessively high. It should not make much difference on your efficiency if you are ending up with the right volume into the fermenter but I would lower the heat. You will have to adjust your preboil volume if you do though so maybe get the efficiency under control then work on the boil off rate.

BTW, I don't think flaked grains and 6 row have much to do with things. I have used flaked grains but I have never used 6 row

My boil off is high because of the amount of heat the Hellfire puts out. It's at about as low of a boil as I personally am comfortable with.

In regards to the 6 row, I mention that because with large amounts of flaked you need extra enzymes which the 6 row provides for you.

 

[behindthetimes]

It's probably the crush. Next guesses in order of likelihood:

- Too low of a mash temp because strike water's not hot enough and/or you're losing temp too fast from your mash tun

- Too low or high mash temp because your thermometer is lying to you

- Too low gravity extraction from sparge from not stirring it enough

- Bad quality grain

 

[trav77]

Yeah not a bad idea to validate your thermo as well.

 

[ajm97210]

I appreciate everyone's replies!

It's probably the crush. Next guesses in order of likelihood:

- Too low of a mash temp because strike water's not hot enough and/or you're losing temp too fast from your mash tun

- Too low or high mash temp because your thermometer is lying to you

- Too low gravity extraction from sparge from not stirring it enough

- Bad quality grain

I'm thinking it's the crush. I have a ThermaPen so it's pretty accurate. Mash temp could also be a slight issue. Quality of grain probably isn't the issue, I work at my LHBS and our grains are really fresh and I got the higher quality 2 row for the blonde but still had the issue.

One of these days I'll get my own mill but I'll try crushing twice. Thanks again everyone!

 

[kh54s10]

My boil off is high because of the amount of heat the Hellfire puts out. It's at about as low of a boil as I personally am comfortable with.

In regards to the 6 row, I mention that because with large amounts of flaked you need extra enzymes which the 6 row provides for you.

I thought that was the advantage of the Hellfire over the original. That you could go lower on the low end. You do not need a vigorous boil. I go as low as I can with my SP10 and keep the flame from going out. I am on the high end of most at 2 gallons per hour.

I mention 6 row as I have never used it. 2 row adds the enzymes that you need. As do many other base malts.

 

[RM-MN]

My boil off is high because of the amount of heat the Hellfire puts out. It's at about as low of a boil as I personally am comfortable with.

In regards to the 6 row, I mention that because with large amounts of flaked you need extra enzymes which the 6 row provides for you.

It's time for you to get comfortable with a lower boil. It's also time for you to get your own grain mill so you have full control of the milling.

Trub loss? 3/4 gallon? That's gonna knock your brewhouse efficiency too, Dump it all into the fermenter. 6-row isn't needed for the amount of flaked grains either. Plain 2-row contains enough enzymes to convert itself and nearly twice its weight in flaked grains. You are nowhere near that limitation.

Full conversion? I doubt it. Spend about $10 at the local pharmacy for a bottle of iodine. When you think your mash is done grab some of the wort with grains in it and drop some iodine on it. If it turns blue there is starch left. Discard the sample.

 

[oylerck]

Things I would suggest but I'm not 100% because I'm still figuring out my effeciency. I know everyone has stated grain crush.

1. Have you tried without brewing salts? Maybe the PH is too low? I don't know if it is worth getting a PH meter because I'm understanding I must calibrate it every single time...

2. Are you stirring the mash a couple of times? From what I see online if you stir lightly a few times without touching the bottom half of the mash you raise efficiency. That and one last time at the end before you Sparge.

 

[Bobby_M]

The salt additions would be fine if building from distilled or RO but if it's an unknown source it could working against you.

Crush is probably the issue. If you work there, surely you can adjust the mill. Throw a handful through at current adjustment and take a picture.

 

[officeboy]

How about your post mash grains, are many of them still intact? Seems like mine are soft/crunched, but not opening up (still sealed in the husk) I also have problems with efficiency in the low 60s and double crushing does seem to help, but even then I can only get into the high 60s.