Please help me improve my BIAB efficiency

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doug293cz

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"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.
Whoever authored that analogy doesn't know very much about diffusion. Diffusion processes typically proceed at rates inverse to the square of the diffusion distance. If you have to diffuse twice as far, then it takes four times as long. There are multiple diffusion processes involved in a mash. Water has to diffuse into the surface of the grain particles, the starch has to gelatinize/solublize, amylase enzymes convert the starch to sugar, and sugar has to diffuse out of the grain particles into the free wort. This all proceeds from the outside of the grain particles towards the centers. The larger the particles, the longer the process takes. So, a mash with smaller particles will complete faster than a mash with larger particles.

Brew on :mug:
 

rjschroed

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I use this for my water chemistry http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/

It too agrees that your mash wasn't acidic enough, it also notices you are a little light on Ca and SO4. All of these problems can be fixed with salt additions. I don't know how much it will help your mash efficiency problem but this one can't hurt to get right and will add no extra effort (FWIW, I'd have gone with 4g CaCl and 2g CaSO4) . I think just about every solution has been beat to death at this point.

My other comments,
Adventures is a good place
I too noticed the 1.030 to 1.040 thing. With the DME you should've ended up at 1.043 (I calculated it early but might have the exact number wrong, regardless, this doesn't help us with your mash efficiency)
I calculate that 1 lbs of DME adds .007 gravity points but we are splitting hairs there.
All good advice: Better crush, Better stirring, Longer rest (esp. if you are now questioning conversion)

The question is, where to start so that you can discover the solution?
 

halcyondays

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Honestly, upping your base malt to hit your desired SG is also an option. Not sure why your efficiency might be so low but a super easy way to compensate is to plug that all in to BeerSmith and adjust your base malt based on your gravity. An extra pound or two of base malt is only a couple bucks per batch.
 
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Calypso

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Reporting in! I did a finer crush with a hand mill, measured mash pH 5.25 at 15 minutes, and did a 1.5 gallon dunk sparge for 10 minutes. Measured efficiency at 69.1%. So a definite improvement! Thanks for the suggestions. I don't know which one did it, or if it was all of them, but they're easy enough that I'll just do them all for now.
 

pricelessbrewing

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Glad to hear it man. Can't remember what all was suggested, but also make sure you stir well before pulling the bag after the mash and after the dunk sparge.
 
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Calypso

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Oh right, I did stir longer, more often, and did a longer (60 minute) mash.
 

jtratcliff

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Reporting in! I did a finer crush with a hand mill, measured mash pH 5.25 at 15 minutes, and did a 1.5 gallon dunk sparge for 10 minutes. Measured efficiency at 69.1%. So a definite improvement! Thanks for the suggestions. I don't know which one did it, or if it was all of them, but they're easy enough that I'll just do them all for now.

It's always the crush.... :D
 

unionrdr

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Yeah, getting an even crush & stirring the dunk (batch) sparge really did it for me. Less than a ten minute dunk sparge, even with stirring, didn't work quite as well @ 168-170F.
 

h22lude

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Just quickly read through this. Not sure who said it but someone on page 4 said running the grains through the mill twice doesn't do anything. That is 100% wrong. Running the grains through the mill twice will give you a slightly finer crush the second time. It also depends on how big the mill gap is. If you LHBS has the gap set too wide, even running through a second time won't crush it enough. Your best bet there is to buy your own mill and set the gap to your liking. BIAB crush needs to be finer (as you know) but a LHBS won't set their gap for BIAB as I'm sure more people come in for typical AG want a normal crush. My LHBS owner is awesome. He knows his stuff. He works for a big local brewery in distribution and he also helps small start up breweries to get started. I was having efficiency problems as well. I bought a mill and my efficiency went up. Moral of the story, even if the LHBS is the best around you may not be getting the crush you need.

I have three suggestions for you. You can pick and choose which ones you want or do them all. They should all help. 1) Get your own mill. 2) Add a little more base malt. 3) Get a pump and sparge arm. Recirculate during the mash. IMO, recirculating will help a ton.
 

Gavin C

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+1

A finer milling via single narrow gap crush or a double milling at a more conventional setting results in a finer grist.

If I remember correctly, you don't have a mill. Your blender can be used.
 
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Calypso

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I couldn't use the handmill at my LHBS this time and was forced to double crush on their regular mill. Here's a picture of the crush. Do you think it is not fine enough?

IMG_20150609_172929.jpg
 

Gavin C

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I couldn't use the handmill at my LHBS this time and was forced to double crush on their regular mill. Here's a picture of the crush. Do you think it is not fine enough?
I think it looks too coarse and lacks consistency. Some big pieces, some whole kernels and some flour. For BIAB you can go alot finer than that.
 
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Calypso

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I just ordered a Millar's barley mill, so I'll just mill my own grains from now on.
 

doug293cz

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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.
This theory has bee refuted by Kai here: http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness
"In the limit of attenuation experiments it was shown that a 5 l/kg (2.4 qt/lb) mash showed much better conversion efficiency than a 2.5 l/kg (1.2 qt/lb) mash. This is also supported by anecdotal experience from home brewers who found that thin mashes generally lead to better overall efficiency."​
There is some more detailed explanation to support this at the link.

Thinner mashes (ie "too much water") do not reduce conversion rate or efficiency.

Edit: Very curious, the post I quoted has disappeared. I didn't think there was a way to delete a post. Anyone know what's going on?

Edit2: I think an Admin spiked it. I noticed when I quoted it that there were what appeared to be some spam links in it (but, I couldn't see them in the original post. Strange.) I deleted those from the quoted part of my response.

Brew on :mug:
 

balrog

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This theory has bee refuted by Kai here: http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness
"In the limit of attenuation experiments it was shown that a 5 l/kg (2.4 qt/lb) mash showed much better conversion efficiency than a 2.5 l/kg (1.2 qt/lb) mash. This is also supported by anecdotal experience from home brewers who found that thin mashes generally lead to better overall efficiency."​
There is some more detailed explanation to support this at the link.

Thinner mashes (ie "too much water") do not reduce conversion rate or efficiency.

Brew on :mug:
Oh, you and all your logicy logicalness! I know for a fact, based on what I think I've heard others say they thought some people felt they kind of figured, that ... wait. What? Facts?! We're supposed to use *FACTS* here?

Seriously though, thank you for the link. I loves the facts. They're so yummy.
 

balrog

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Did they magically get eliminated from my quoting you?

Maybe I don't have the special spy glasses from the cereal box allowing me to see the embedded spambots.
 

doug293cz

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Did they magically get eliminated from my quoting you?

Maybe I don't have the special spy glasses from the cereal box allowing me to see the embedded spambots.
No, when I hit the "Quote" button, they were in the quoted text, but I deleted them. I'm thinking that I didn't see them in the original post because they were links to sites that require javascript in order to see anything, and I use NoScript to block javascript from unapproved sites.

Brew on :mug:
 
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Calypso

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I know it's an old thread at this point, but I put my new Millar's mill to the test last night. Got a nice, fine crush. 88% efficiency!
 

doug293cz

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I know it's an old thread at this point, but I put my new Millar's mill to the test last night. Got a nice, fine crush. 88% efficiency!
Congratulations! Sounds like you've got things under control now.

Brew on :mug:
 
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ok here's how to improve your efficiency,

things you will need, two clean 6.5 to 7 gallon buckets, I wear steam gloves but thats optional, buy a pump, 2 ball valves, hose and some fittings, something to keep the bag from scorching, some clamps to hold the hose in place

mash your beer like normal but recirculate over the top with the pump for at least 60 minutes, at this point instead of raising and draining, leave the mash inside the pot but drain the wort into a bucket, fill the other bucket with clean water I prefer 6ph water, pour the water on top of the grain and recirculate for 10 minutes or so cleaning the rest of the sugar off, when done raise the grain and discard, don't bother draining. pour the remaining wort back into the pot then boil.

if done correctly you will get at least 80 percent if not more:)

p.s. be careful on how much water you add total, I recirculate with 1 inch liquid above the grain bed
 
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