BIAB low efficiency - Grain Milling

[jacarmichael]

Hello all, Just completed my first BIAB brew this past weekend, but got a low mash efficiency (54.9%). I ended up adjusting the OG with DME, but tracing my steps, I believe the cause of the low efficiency was the milling of the grain. I have attached a picture of the milled grain, if anyone has an idea if that could've been the cause.

Recipe:
OG 1.045
7.6L (2 gallon) batch
2 lb of Weyermann Pale Wheat Malt
2 lb of Briess Pilsner Malt

15 g Hallertau hops @ 60 min

Mash:
60 min @ 152 F
5.5 L Water
Batch sparge 4 L of water

2 gallons into the fermenter, with OG 1.046 with the adjustment with DME.

 

[botigol]

The crush is definitely part of the issue. You have a lot of, seemingly, uncrushed grains in there.

 

[oujens]

The grains seem wet to me, so not sure if I'm viewing this correctly but I would agree it almost seems like it was not crushed very well. Not sure if its easy for you, but a grain mill for any all grain setup is a nice thing to have to avoid things like this.

 

[Rockn_M]

Where did you get your grain milled? If at a homebrew store I would ask them to mill it again, if your grain looks like that again. It should be close to flour. I recently purchased my own grain mill and my efficiency went from 60-65 to about 85%. The only change was I milled my grain much finer than I was getting at the homebrew store.

 

[RM-MN]

Hello all, Just completed my first BIAB brew this past weekend, but got a low mash efficiency (54.9%). I ended up adjusting the OG with DME, but tracing my steps, I believe the cause of the low efficiency was the milling of the grain. I have attached a picture of the milled grain, if anyone has an idea if that could've been the cause.

Recipe:
OG 1.045
7.6L (2 gallon) batch
2 lb of Weyermann Pale Wheat Malt
2 lb of Briess Pilsner Malt

15 g Hallertau hops @ 60 min

Mash:
60 min @ 152 F
5.5 L Water
Batch sparge 4 L of water

2 gallons into the fermenter, with OG 1.046 with the adjustment with DME.

You've got it. That grain looks like most of it just fell through the mill without being crushed at all. I'm not surprised you got low efficiency with that. You might have gained some with doing a longer mash but there is only so much to be gained that way.

 

[wilserbrewer]

Crush it and mash again, likely get a nice small beer.

Sorry just being silly. That crush is NG

 

[jacarmichael]

Thanks all for the comments. It was milled at the store so I'll pay closer attention to the milling next time.

P.S. the grain was wet as i took the picture after mashing, when I figured out the efficiency was so low.

 

[Chris_Primavera]

Other things to consider:

Do a full volume mash and make sure the grain is not constricted.
Mash 90 minutes
Stir at least every 20-30 minutes
Make sure your pH is not too high

 

[Biscuits]

Can you explain your process a bit more? I am wondering how you started with a total of 9.5L (2.5 US Gal.) and after mash/sparge and boil end up with 2 gallons into the fermentor?

Even with a heck of a bag squeeze and a moderate boil off @0.65 gallon (2.5L/hr), which is what my 3 gallon (11L) kettle does, it would be at least a smidge less than 2 gallons...but at this size of a batch every little bit counts.

I am wondering if combined with the crush, you also mashed/sparged with more water than you meant to.

 

[jacarmichael]

Can you explain your process a bit more? I am wondering how you started with a total of 9.5L (2.5 US Gal.) and after mash/sparge and boil end up with 2 gallons into the fermentor?

Even with a heck of a bag squeeze and a moderate boil off @0.65 gallon (2.5L/hr), which is what my 3 gallon (11L) kettle does, it would be at least a smidge less than 2 gallons...but at this size of a batch every little bit counts.

I am wondering if combined with the crush, you also mashed/sparged with more water than you meant to.

I did the mash with 5.5 L, then sparged with 5.1 L of water to pre-boil volume of 10.6 L, which after boiling 60 min and transferring to fermenter, ended at 7.6 L of wort.

 

[Nodak_Brewer]

Honestly, simplify the process. Use a single volume, no sparge method or just do a basic dunk sparge. Once you get a good conversion efficiency with your crush, you can make it more complicated. At least you'll have eliminated a variable. I just completed my first BIAB and got 72-75% efficiency using grains I crushed with a Victoria mill. My crush wasn't fine enough, and it was much finer than yours. You could definitely get away with crushing at <0.030, or less than the thickness of a credit card. Mine was set at 0.025 and I might crush even finer in the future.

edit: my batch was 1.75 gallons in the fermenter, 2.75 to start. I squeezed the bag harder than Lennie with his bunny rabbit as well.

 

[Biscuits]

I did the mash with 5.5 L, then sparged with 5.1 L of water to pre-boil volume of 10.6 L, which after boiling 60 min and transferring to fermenter, ended at 7.6 L of wort.

That still doesn't make sense. You would have lost liquid during the mash from grain absorption, there is no way, even with an insane bag squeeze that you're mashing with 5.5 L and draining 5.5 L.

 

[C-Rider]

Since you are doing BIAB and 2 gallon patches like me you can mill your grain at home if you have a blender. I can process 5 lbs in like 7 min. I turn the grain into flour in the blender and usually get about 80% eff in my brews.

I use a 5 g round cooler to mash and a 5 gallon pot to boil. Fermenting in 2 g HD buckets. (paint buckets).

 

[RM-MN]

Thanks all for the comments. It was milled at the store so I'll pay closer attention to the milling next time.

P.S. the grain was wet as i took the picture after mashing, when I figured out the efficiency was so low.

With the low cost of the Corona style mills you might want to just get your own. Set as fine as possible, my first BIAB batch, full volume, no sparge netted me 80% efficiency. With that as a start I soon went to buying base malt in 55 lb bags at a considerably lower cost. By the time I had used up the first bag, the savings paid for the mill plus.

 

[jacarmichael]

That still doesn't make sense. You would have lost liquid during the mash from grain absorption, there is no way, even with an insane bag squeeze that you're mashing with 5.5 L and draining 5.5 L.

You are right, I did not include that in the message. The assumed volume loss due to grain absorption was 0.9L, so I started with 5.5 L, assumed 0.9 would get absorbed, added 5.1 L to get 9.6 L pre-boil, and end with 7.6 L final volume. Any other issues you spot with my calculations?

 

[jacarmichael]

Since you are doing BIAB and 2 gallon patches like me you can mill your grain at home if you have a blender. I can process 5 lbs in like 7 min. I turn the grain into flour in the blender and usually get about 80% eff in my brews.

I use a 5 g round cooler to mash and a 5 gallon pot to boil. Fermenting in 2 g HD buckets. (paint buckets).

Thanks for the suggestion, had not thought about this. Will give it a try for my next batch.

 

[pricelessbrewing]

You are right, I did not include that in the message. The assumed volume loss due to grain absorption was 0.9L, so I started with 5.5 L, assumed 0.9 would get absorbed, added 5.1 L to get 9.6 L pre-boil, and end with 7.6 L final volume. Any other issues you spot with my calculations?

If you're not measuring your volumes, you can't really talk about efficiency. Efficiency calculations require accurate volumes, and gravities.

 

[jacarmichael]

If you're not measuring your volumes, you can't really talk about efficiency. Efficiency calculations require accurate volumes, and gravities.

Thanks, I'll pay more attention to measuring volumes for my next batch, together with ensuring my grain is finely ground.

 

[atcsat]

Since you are doing BIAB and 2 gallon patches like me you can mill your grain at home if you have a blender. I can process 5 lbs in like 7 min.

I can't believe I haven't thought to do that. My LHBS can't change the grind setting so they run it through twice which helps. My efficiency always good (around 75%) but could always be better!

 

[pricelessbrewing]

I can't believe I haven't thought to do that. My LHBS can't change the grind setting so they run it through twice which helps. My efficiency always good (around 75%) but could always be better!

I found it to be a huge pain, I tried it once. Definitely recommend a corona mill over this. They're $25-40. Buy a mill, don't fry your blender.

 

[Nodak_Brewer]

I constructed an "ugly junk" corona mill setup as seen in the ugly junk mega thread for less than $40. I prefer it over my cereal killer despite the torn husks, which I think would be way too torn up in a blender for anything but biab.

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[pricelessbrewing]

I constructed an "ugly junk" corona mill setup as seen in the ugly junk mega thread for less than $40. I prefer it over my cereal killer despite the torn husks, which I think would be way too torn up in a blender for anything but biab.

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OMG I LOVE THIS ONE! I like that it's not mounted inside something, and only the grinding plates are enclosed to reduce dust and grain spewing everywhere. This is getting assembled tomorrow.

 

[C-Rider]

I found it to be a huge pain, I tried it once. Definitely recommend a corona mill over this. They're $25-40. Buy a mill, don't fry your blender.

Picked up a great Osteriser Blender at Goodwill for 10 bucks. Brand new. I you are doing small amounts of grain and only put in 1 coffee cup at a time you won't fry your blender unless it's a cheap one.

 

[TexasWine]

Picked up a great Osteriser Blender at Goodwill for 10 bucks. Brand new. I you are doing small amounts of grain and only put in 1 coffee cup at a time you won't fry your blender unless it's a cheap one.

I've done about 1 lb at a time in mine, but it's a pretty decent blender (Blendtec).

 

[RM-MN]

I constructed an "ugly junk" corona mill setup as seen in the ugly junk mega thread for less than $40. I prefer it over my cereal killer despite the torn husks, which I think would be way too torn up in a blender for anything but biab.

[/URL][/IMG]

Moisten the grain (not much water, best done with a mist) and let it set for a few minutes before milling. That will toughen the husks so they don't tear as easily. Use your hands to mix in the moisture too, you want all the grain to be moist.