Jamato, brewing as long as you have been, you already know what the proper crush size is for grain. You do not need to crush any finer for BIAB. I also assume your grain weight was accurate.
I would attribute the 0.006+ shortfall in OG mostly to your mash schedule.
See this for reference http://howtobrew.com/book/section-3/how ... ng-defined
You held temperature at 122 ºF for 15 minutes - that's in the proteolytic enzyme activity range at pH=5.2. As far as I know, that time and temperature combination does not contribute to OG.
Your mash at 150 ºF for 60 min gave what you got. A 90 minute mash would have given you more. So a 60 min mash doesn't quite reach your target. Take a look at the upper left graph here http://bit.ly/2pnFnSH and you will see that you missed out on the 30 minutes that might have given more Fermentable Sugars (FS).

No mash out?

One more thing, how long was the boil time? Using the BIABacus, we employ a (compared to 3V brewing) more dilute mash, so a 90 minute boil results in higher gravity than the common (elsewhere) 60 minute boil.

Was your pH at 5.2 before you added the grains? if so, the grains themselves may have lowered the pH to 5.1 and then it is pretty low for mashing. It's not likely with the grain bill you listed. My well water comes out of the ground at about 5.3, and I use it that way instead of post in-house water treatment. I have to watch that my grist doesn't lower it to 5.1 or my OG drops a bit. It really only worries me with dark or acidulated grains.

Here's a thread http://www.biabrewer.info/viewtopic.php ... phs#p55312 see the post at the bottom of the page.

Did you take a Specific Gravity reading at the end of the mash? Did you stir the mash at all?
That's all I can think of.

Pistol Patch has written many times about mash efficiencies and 90 minutes. Look around for more. http://www.biabrewer.info/viewtopic.php ... ncy#p54717

Summary, do a full volume BIAB mash for 90 minutes with periodic stirring, then a 10 min mashout, pull the bag, then a 90 min boil and your SpG reading will be higher. If you sparge (holding water back in Section W) it can be even higher still. But I can stir up trouble if I talk about that.....

Hi Jamato,

Is your kettle large enough to do a full volume mash? If so, I would suggest trying it without the sparge...

With full volume BIAB you are mashing all the grain in all the water for the entire mash time. (passive or continuous sparge) This is better than mashing in only some of the water and then rinsing for a very short time with the remainder. There are numerous posts on this forum (mostly authored by PistolPatch) about why full volume mash is actually more efficient than holding water back for sparging.

If you want to try and find the posts maybe try a forum search for Jeans, if i recall correctly.

Just my 2 cents, good luck !

Definitely go as goul suggests. If you sparge, you are losing the main beauty of BIAB and costing yourself more work for no gain.

Just as an aside, myself and many others here moved from three-vessel to Single-Vessel All-Grain (Pure BIAB); one member even had a home-built hermes that cost him hours to build and about $3,000. He now brews SVAG in an urn not because he finds it easier but because he thinks it makes better beer.

Let me see if I can find some links for you that relate to the above, including those that goul mentioned...

Number Respect and Disrespect
Some Common Reasons for a Low Efficiency Reading
Kettle versus Fermenter Efficiency
Sweet Liquor Shop 1
Sweet Liquor Shop 2
Sweet Liquor Shop 3
Sparging and dirty jeans
More dirty jeans
Brew Day Measurements

Some or all of the above you might already know however we have found that the above are rarely, if ever, discussed on other sites so maybe there is some new stuff there?

Been glad to see you enjoying the forum and helping others too .
PP

Hey Jamato,

A quick reminder... As Goulaigan says, remember that a traditional full volume BIAB mash is a continuous mash and sparge. You don't want to think of it as skipping the sparge, rather spending a similar 90 minutes to do both at the same time. And PistolPatch (in the past) has put forth a good argument to do a 10 minute "Mash Out" to get an additional point or two.

Unless you are cutting your grain contact time, traditional full volume BIAB has excellent efficiency without additional modifications... And a 10-minute Mash Out is just gravy at the end...

Scott

Hi again Jam,

You do know I can tell you haven't read the links I posted above yet? Those links are really important though and, I also now know, that the info there will be new to you. Set an hour aside and a beer or two to read them carefully though - it is info you won't find anywhere else and is based on a lot of tests.

In hindsight, the info in those links is now completely obvious and logical to me, however, it wasn't initially. It took a lot of thinking, but more importantly, measuring side by side brews to prove this logic was true. The hardest bit for myself and the others who have worked on this was overcoming the education we had received, the same education that brewers are still getting everywhere (unless things have dramatically changed?) except here.

I'm going to trust you will read the above links okay?

After you do, hopefully you'll see how accurate the following is and a big light bulb will flick on that will make things so much easier....

The 'Old' All-Grain Reality

A combination of many, many, things (just two being ambiguous terminology and the complications of measurement in multi-vessel all-grain) resulted in the wide-spread belief that sparging (rinsing) in brewing works exactly like it does in your clothes washing machine. Like you mentioned above, brewers believe that "somehow I am going be leaving sugar in the grain if I do not sparge."

Your clothes washing machine is not like brewing at all. A washing machine is able to spin an incredibly high amount of water, and the dirt that water holds, out of the clothes.

In brewing, we don't have the spin.

Because we have this "washing machine" mentality, we also think, in brewing, that we can get our grain perfectly clean. Even a washing machine can't get things perfectly clean. Would you expect a full load of clothes soaked in oil to come out clean? No. What about white sheets covered in red dust? No.

Most of our clothes do come out clean though as the machine spins and our clothes are rarely at such extremes.

The 'New' All-Grain Reality

Once again, a combination of many things (just two being clear brewing terminology and the simplicity of measurement in single vessel all-grain [what we first called 'BIAB']) allows us to see things more clearly, we see brewing is really like cleaning a very dirty load of clothes (our grain) in a very inefficient washing machine (basically a bucket).

There is no spin cycle in our "machine." In fact, we can't even wring water from the dirty clothes (grist). At least with say a large beach towel, we can have a person at either end and wring water out. What happens though if you roll the same towel into a ball and then try squeezing the water out? Very little.

Hopefully you are with me so far. If so, the following things may become obvious. Let's imagine we are allowed just 50 litres (say 10 gallons) of water to clean a bag of extremely dirty clothes. With no spinning or wringing, is there any difference between the following two methods?

1. Soak the bag of dirty clothes in one bucket containing 5 gallons of water for 60 minutes and then lift the bag into a second bucket containing 5 gallons of water and let it soak for 30 minutes.

OR

2. Soak the bag of dirty clothes in one bucket containing 10 gallons of water for 90 minutes.

To Sum it Up

Like any advance in understanding, this better reality of making 'sweet liquor', comes from looking at things differently. Instead of the old, "How can I get my grain completely clean," we now see, "I only have x amount of water available. How can combine that water and my grain to end up with as dirty water as possible?"

Things now become much easier to understand. We can focus on realities rather than impossibilities or distractions. We realise that any extra water used to clean will have to be evaporated off (we can't leave our clothes under a waterfall until they are completely clean); we realise that 'soaking' time makes a difference and can, in fact, be critical with some clothes (malts); we are forced into examining more subtle things such as agitation; we easily understand that really dirty clothes (high gravity beers) will never come out as clean (they'll always have a lower kettle efficiency) than lower gravity beers*.

...

I think that and the links above are enough to keep you busy for a tad Jam . Let me know if the light bulb appears!
PP

*The BIABacus is the only software the new reality automatically. I suspect you'll be exploring that too within a month

You'll be fine on the BIABacus (it can even handle three-vessel brewing btw). It looks daunting (mainly because everything is on one page) but is very fast to learn and, surprisingly, much faster to fill in than other software. A lot of sections, for most brewers circumstances, aren't even necessary.

Please let me know how you go with it or if you need any help

Hi Jamato,

Glad to hear things worked out for you! It's a good feeling for sure when you are within a percent or two, plus or minus, of efficiency expectations.

For me, going through the numbers (besides in the "general sense"...not pondering specifics, easier to make sense of everything with a BIABacus file to review.

Anyhow, good job!

Good on you Jam!

I was pleased to see your of a few days ago showing that you had your head around the BIABacus

Post your BIABacus file up here with your "actuals" if possible. As Scott said it really helps to spot anything that might be awry.

The only thing that concerns me is "heated 3 gallons, that's ,used it to sparge until 7 gallons collected, or ." You'll see in this thread that Clackers did the same and I wrote a few essays there on why that can be a problem.


PP

Yep, if your kettle isn't large enough to full-volume mash then you will have to sparge or top up the kettle pre-boil*. Your kettle wasn't large enough so, it wasn't your decision to sparge that worried me, it was your decision to sparge until your Volume into Boil matched the BIABacus estimate in Section K.

While we don't have your pre brew day BIABacus, I'm pretty sure that you either didn't fill out Section W before brew day or, if you did, then you did not use the same volume of water that you had typed into Section W to sparge.

The main thing if your kettle is not large enough to full-volume mash is to make sure you fill in the appropriate fields in Section W before you brew. Then, on brew day, use exactly the amounts you have in Section W. You only adjust the gravity of wort just before pitching as, by then and only by then, will you have reliable volume and gravity readings.

I just added another essay to Cracker's thread re the problems of not filling out Section W and, then on brew day, using the volumes you have typed there. It's a hard read but it also might help to trigger an "aha!" moment in some area/s that might still be confusing.


PP

* Also, remember, if with a small kettle you decide to sparge, you won't need more grain but it will add to your brew day labour/work/inconvenience. In contrast, if you decide to top-up, you'll need a bit more grain but save labour/work/inconvenience.