So, I did not use a "Brewhouse Efficiency" or "Into Kettle Efficiency" fudge factor to calculate my volumes and grain bill.

Rather I used the Malt Spec sheet's FGDB%, a well researched Absorption factor and my personal boil-off figure. And the results were, as far as I'm concerned VERY accurate.

This leads me to believe, that providing the Potential Extract % is accurate and the Boil-off figure is accurate this calculator should be able to accurately predict grainbills and volumes to achieve most any BIAB brewsize.

And from my tests, the Sparge section should work too... and can be used to bump up the Into Kettle efficiency up to about 90% even for the Big Beers.

Now to think about adding some Maxi-BIAB support

I've added a Kettle Top Up field.

This is an intersting thing as with the Sparge Water field and the Kettle Top up field there are two approaches which can be used to squeeze a big beer into a small kettle.

Which allows us to play some interesting what-if games.

Using the example of my NS Ale brew on the weekend.

Start of Boil Volume (100C) is 37.02L with 1.036
End of Boil Volume (20C) is 25.5L at 1.050

For standard BIAB grain requirement is 5.25KG

For an Into Boil Efficiency of 82% and Into Fermenter Efficiency of 74%
Now, that batch has a mash tun requirement of 44.96L, so If I wanted to fit this in my hypothetical 40L kettle then I would need to use 6L of topup water after pulling the bag.

If I modify the settings to include 6L of topup, my grain requirements shootup to 5.48KG, my into boil efficiency drops to 78.5% and my Into Fermenter efficiency drops to 71%

And my Mash will use up about 39.2L, thus fitting in my kettle.
BUT say I chose to do a 5L sparge, instead of a 6L topup, my mash requirements are still 39.22, but now my grain bill is only 4.86KG!

And my Into Boil efficiency is 88.5%

And my Into Fermenter is 80%
Which leads to another question.... what if I used more sparge water and less strike water?

Say I used 16L

Now my grain requirements are 4.7KG, my strike water is 24L, my mash volume requirement is 27.74L and my Into Boil Efficiency is 92%

!!!!

My liquor to grain ratio is still quite reasonable at 5.12L/KG

The mash gravity is *just* 1.053


But my Into Fermenter efficiency is 83%
So, what would you do? 600g of extra grain and a just toss some extra water into the kettle? or muck about with a dunk-sparge and save 600g? fairly big chunk of grain really

PS: to further increase the system efficiency you would need to have a better kettle pickup system than I do, but say you had 23.5L into fermenter... which would be the limit from this bill, then you'd have 85% Into Fermenter Efficiency off the same 92% Into Boil efficiency. I just don't think that's going to happen without straining the trub.

I wonder what would happen with two dunk sparges...

This is my current version of the CE BIABcalc which features Kettle Topup

I've added a few Weyermann grain stats, and the grains tab *is* linked to the Potential Extract tab and *does* affect the potential of the grains. The grain contribution and scalings do work.

If you want to use grains which are not present, simply add them, or just use 80% as a guess.

I also 'corrected' the 70C expansion factor by using the one from BIABacus, not braukaiser.

This should work with LibreOffice 3.4.3 and Excel

made some edits to first post

Did another brew today.

Results were fairly good. I set my mill gap to 0.5mm. Evaporation was lower than expected, and absorption was lower too...

Anyway.

I hit 99.5% conversion efficiency, and 82.7% Boil Efficiency

mankang wrote:Stux, just wanted to let you know that I follow this thread with great interest.

Thanks mankang,

I've been working on an update

But its quite complicated

Basically I've added Into Fermenter volumes etc...

I've also added the ability to do Mash Tun, Start of Boil, End of Boil and Cube Limits

With sparging and topups if necessary... so basically, I've added everything necessary to use this approach for Maxi-BIAB... which was... tricky

And, if you don't specify any limits, you get the same results as the current version up here...

Once I clean this up, I should be able to then add Imperial/US unit support, and a few other neat things

I've been working on a new version of this calculator, which implements all the necessary machinery to do Maxi-BIAB calculations... but that's not the point of this post

I did another brew on the weekend and was very happy with the results (and the brew!)

I decided to redo my Hefeweizen (50/50 Wey Pils/Wheat), but this time with a 5 step mash. Well, the mash makes no difference.

Conversion Efficiency = 99% (which I think should be the default)
Real Absorption = 1.3L (range seems to be 1.2 to 1.4L depending on how agreesively you squeeze, and the coarseness of your grind)

I set my 90 min evaporation to 9.38L, which is based on 6.25L/hr, which is what my BeerSmith 2 is set to. I suspected my evaporation is actually closer to 10L over 90mins, but I'd rather underestimate evaporation, than overestimate

New Settings
Do You Cube Your Wort? Yes
Kettle Loss = 3L
Cube Loss = 2L

Mash Tun Limit = 49
Start of Boil Limit = 40
End of Boil Limit = 40
Cube Limit = 23

(note, all of those new figures are hidden by default, and in reality the limits aren't needed for my equipment with a single batch)

And then the Brew Requirements

Desired Fermenter Volume = 21L
Desired Fermenter OG = 1.050

And Sparge Water = 0L

I already have the Wey Wheat and Pislner grains entered, and the average potential for the grainbill is 78.25%

CE Calc tells me

Grain Bill = 5.210KG (2.605 of each grain)
Total Strike Water = 39.31L
Total Mash Volume = 42.96L
Liquor to Grain Ration = 7.54 L/KG

And my expected results are

Expected Start of Boil Volume (100C) = 36.42L
Expected Start of Boil Gravity = 1.037
Expected Into Boil Efficiency = 83.0%

Expected End of Boil Volume (100C) = 27.04L
Expected End of Boil Volume (20C) = 26L
Expected End of Boil Gravity = 1.050

Expected Into Fermenter Efficiency = 67.00%

Nice round numbers

...

Now for my next trick, I wanted to update my recipe in BeerSmith, and see how everything scales... My original recipe was a triple batch maxi-biab!

So, I updated my equipment profile a little bit... Most was already the same

Brew House Efficiency = 67% (based on the CE Calc Into Fermenter number)

Mash Tun Volume =49L

Loss To Trub and Chiller = 5L (3L in Kettle + 2L in cube, same as ce calc)
Batch Volume = 21L, same as CE's Desired Fermenter Volume
Fermenter Loss = 2L (irrelevant really)

Boil Off was already 9.38L for 90 mins, which gave a Boil Volume of 36.41L, which is remarkably similar to the the 36.42L predicted by the CE Calc

I then applied this new equipment profile to the recipe... and adjusted the grain to 5.2KG

BS2 is then predicted a Mash Efficiency of 83.0%... hey whatdya know, exactly the same as CE Calc...

It also predicts 39.51L of strike water... which is just 100ml more than the CE Calc prediction. This is because BS2 is using a different absorption figure, which I have left at the default

BS2 is predicting 42.98L for Mash Volume, CE Calc is predicted 42.96L, that's the extra 100ml I guess, but close enough

BS2 is predicting 27.04L post boil volume, which is the same as the CE Calcs...

So, basically, all volumes are predicted as the same...

where it gets interesting is BS2 is predicting an OG of 1.052 and CE Calc is predicting 1.050.

Hmmmm... we have a contest

Which brewing software will be right




Soooo, I did the brew

I mashed in at 35C, and measured the volume, 43.2L, which is close enough to the 43L predictions...

Measured Start of Boil Volume was 36.3L, just 300ml off the target... well within my margin of error...

(Absorption was 1.32L instead of 1.3L/KG!)

Gravity was 1.037, as predicted, interestingly this indicates a conversion efficiency of 98.5%... but if I had 1.0372, then it would've been 99%... so that shows you, the limit here is the accuracy of my hydrometer. Or another way, 0.2SG points = 0.5% conversion efficiency

End of Boil Volume = 26.5L, when we were aiming for 27.04L, so 500ml off, which is because I underestimated evaporation.

Actual evaporation was 9.8L instead of 9.38L

Gravity = 1.051, which means a final Kettle efficiency of 92.9% which is close enough to the predicted 83%

So... If I added another 500ml into the pot, then it would've been the 1.050, and the efficiency figures and conversion figures etc were exactly spot on.

NOTE: I did NOT use 83% efficiency to calculate the grain bill

But BeerSmith 2 did... and BS2 was predicting 1.052... where as I really did get 1.050 at 27L, or 1.051 at 26.51L

So, that's another tick to the CE Calcs numbers

Based on my full cube and my 3L of trub, I should get 21L into the fermenter at 1.051, and if I do that, the CE Calc is telling me I should add 420ml of water to the fermenter.. which I probably won't... I wanted 1.050-1.052 anyway!

End result... the CE Calc was pretty much spot on. BeerSmith 2 was not, and I was only out by how far out my evaporation estimate was.

Every test I have done has shown that the methodology used by the CE Calc is correct and its results are correct, and it does not vary based on magical BrewHouse or Kettle Efficiency numbers.

I'm uploading my latest version of the CE BIABcalc.
This version works in LibreOffice 3.4.3, but you might need to move the pie graph.

This version includes Maxi-BIAB support. What that means is it features optional

Sparging & Topups, Pre, During and Post Boil

Its features support for No Chill cube limits and losses, kettle losses, fermenter dilution etc.

Features data hiding, so that unused fields are hidden until you trigger them. For example, if you don't No Chill, you don't see the No Chill limits and losses. if you don't set a Mash Tun Limit then you can't set an Start of Boil or End of Boil limit. Etc.

How do I use the CE BIAB Calc?

I'm using the 2011-11-27 version.

First things first. You need to know your total evaporation.

If you evaporate 4L/hr, and you're doing a 90 min boil, then 4L/60 mins * 90 mins = total evaporation.

Enter your Total Evaporation in the Total Evaporation field

Leave Conversion Efficiency and Real Absorption at 99% and 1.30L respectively.


Next thing is to enter the malt bill...

switch to the grains tab

I have entered some grains, and their malt specs. Essentially you need to fill in the Grist Bill column with values which are used derive the percentages...

For a 50/50 Weyerman Pilsner/Wheat beer I set Grist Bill to 50 and 50 for the Wey Wheat and Pils grains, and leave everything else blank. The calculator does the rest.

You could use Pound, Grams, Kilograms, or any other unit in the Grist Bill column. Everything is treated as a ratio.

....

Now lets finish entering everything.


If you No Chill, then set the "Do You cube your wort?" field to "Yes" otherwise "No"

Enter your kettle loss buffer amount in the Kettle Loss field. This would normally be about 10-12% of your brew. I expect 3L of loss in my kettle, because I like a large buffer, and I can use the left overs for making starters.

If you No Chill, and you leave the cold break behind in your cube, then enter your cube loss. I leave about 1-2L behind usually, so expect 2L loss.

Enter the size of your mash tun, or you mash tun limit. I have a 50L pot, and I'm comfortable having up to 49L of mash in that, so I use 49L. If you leave it as zero, then your pot is assumed to be infinite, which is a standard biab.

If you were really pushing things, you might want to set a start of boil and end of boil limit. In my 50L pot, I prefer not to have more than 40L in the pot for start and end of boil. But unless you set a mash limit, you won't even have this option.

If you were cubing your wort, you might set a cube limit. If not, then you won't even have the option. Again, this is a maxi-biab thing, and you could leave it as zero. My 20L water no-chill cubes hold 23L, so that is my Cube Limit.

If you are planning on sparging, then set Sparge Water to how many L of sparge water you expect to use. Your Dunk Sparge volume will be revealed



And that is it.

Mash Requirements will be calculated, your Grain Bill and Strike Water will be displayed (the green backgrounded cells), and your Mash Volume.

If you require topup water that will be displayed too... If you are using topup water you may want to consider setting some sparge water instead, this will increase your efficiency and lower your grain bill.

You can look at the Grains tab to see the Updated Grain Bill column, for actual grain amounts.

If your Grain Bill reads as "#########" it means your brew was impossible to mash. This will only really happen if you specify a mash tun limit, and don't sparge. You should consider adding some sparge water.

You can see you expected Into Boil efficiency. If its too low for your likings, perhaps you should consider adding some Sparge Water?

...

The Brewday Estimates & Targets provides you with the predicted results of the brewday. They should be pretty accurate.

The Brewday Results, is where you can fill in your actual results, and the calculator can then tell you your updated Evaporation and Absorption rates.

Sparging and Topups

The CE BIABcalc models a Dunk Sparge.

A Dunk Sparge is where you take your grain bag and dunk it into another pot or bucket filled with water, preferably hot, swirls the grains around and allow the water to dilute the extract trapped in the grains... then you pulled the bag, sqeeze it into the bucket, and add the remaining "sparge water" to your brew kettle.

There are two types of Sparge water "Topups" and 3 "Fresh Water Topups" that the CE Calc uses

Sparge Pre-boil Topup is used to topup the kettle to your Start Of Boil Volume. If you need more water than you have sparge water, then Fresh Water Pre-boil Topup is used.

Sparge and Freshwater Topups may be used during the boil to counteract evaporation, if you are pushing things, sparge water is used in preference to fresh water.

And finally, if you are brewing a concentrated wort, then Fermenter Freshwater Topup may be used to dilute back to normal gravity.

You will not see any of these topups unless they are required by limits you have placed on the calculator.

BTW, the sparge modelling is based on work by BrauKaiser, but has not been tested in the real world in this application. I would appreciate anyone who does try a sparged brew letting me know their results!

Can't believe the amount of work you've put in stux, great work

It would improve your efficiency further, which is probably a good idea

Good Day, I once saw an idea for a sparge being a large collander placed over the kettle, and the first Sparge Sprinkled(fly) onto the grain bag until the kettle is nearly full, then..the bag was placed into a second sparge pot. The second pot was used to top up the boil over a 90 minute boil. I did not see what the efficiency ended with. But the second sparge was 1.015s.g. or so.

New version of the CE Calc. I've primarily made some changes to the grains tab, and then filled in far too much detail for Muntons, Thomas Fawcett and Bries Malts

You can now enter FGDB or LDK(DB) with or without Moisture or FG-As Is or LDK(As Is) for any grains. I also made it so some zero values were blanked.

I guess, the only thing left to add is a PPG version for any US malt specs, but I haven't seen PPG malt specs in practise, yet.

AND Yes, the malt specs page is still far too complicated, at this stage the we're still working out what is really necessary... ie do you *really* need a different Roast Barley from each maltster? or is just one Generic Malt good enough?

de5m0mike has tested the CE Calc in an extreme brew using constrained mash and boil limits with a dunk sparge and boil topups aiming for a 1.105 mash and a 1.100 OG beer!!!

And his results are in:

http://www.biabrewer.info/viewtopic.php ... 151#p15886

(He hit his predicted Into Fermenter efficiency within 0.01%!!!)

I think these basically confirm that the CE Calc's theory matches reality, and that the results predicted, even for complicated, extreme constrained biabs are well within the margin of error of our homebrew equipment!!!!

This is a good thing!

Hey ya Stu ,

You and I both know that I have been examining efficiency for over 5 years now. We also both know that the higher the original gravity desired in a brew, the less efficiency, of any kind, you'll get.

But, one brew does not prove anything from my experience. You've seen me write on this time and time again. In Mike's case, he spilt liquor here and did something else there. Who would know how accurate his hydrometer is? And, it was not a full-volume brew.

You also made comments in the linked thread that perhaps, "Maybe you did this," or "Maybe you did that?"

So, whilst I'm very excited about the CE calc, I also strongly disagree with the statement, "I think these basically confirm that the CE Calc's theory matches reality..."

Unless I am missing something obvious, many more brews need to be done (simple full volume ones for a start) before any claims can be made.

Does that sound fair?


PP