Brewfather water needed for batch

[skarp0ye]

In general, do you see the value of it based on the discussion here?

Absolutely, will follow this thread and analyze

 

[ScrewyBrewer]

If you’re using 1kg of grain with 80% potential, that’s 0.4L less water you need to start with.

After tinkering with doug293cz's spreadsheet and following this and similar threads, most examples use 80% FGDB, 4% grain moisture content, 37 as the weighted grain potential and 100% conversion efficiency (ie: 80% mash efficiency). Is it safe to say that those are default values to be used in the majority of recipes?

Another question regarding a congress mash. Do I enter 36 ppg as the weighted grain potential for a recipe that uses 23.5 lbs of 37 ppg malt and 0.5 lbs of 35 ppg malt?

 

[McKnuckle]

To be precise, you have to calculate the weighted average based on all malts in the bill.

For your example, 23.5 is 97.9% of the grain bill, and 0.5 is 2.1%. Multiply their respective PPG values times each percentage, and add the resulting products. You'll get 36.958 PPG as the potential for the whole grain bill.

37 x 0.979 = 36.223
35 x 0.021 = 0.735
36.223 + 0.735 = 36.958

 

[VikeMan]

After tinkering with doug293cz's spreadsheet and following this and similar threads, most examples use 80% FGDB, 4% grain moisture content, 37 as the weighted grain potential and 100% conversion efficiency (ie: 80% mash efficiency). Is it safe to say that those are default values to be used in the majority of recipes?

For the grain specs, every grain is different. I'm not sure why anyone would want to use averages when actually recipe building, unless individual grain data isn't available. (I may be missing the point of the question.)

 

[ScrewyBrewer]

To be precise, you have to calculate the weighted average based on all malts in the bill.

For your example, 23.5 is 97.9% of the grain bill, and 0.5 is 2.1%. Multiply their respective PPG values times each percentage, and add the resulting products. You'll get 36.958 PPG as the potential for the whole grain bill.

Ahh, thank you very much this helps, reworking my formula now.

 

[VikeMan]

To be precise, you have to calculate the weighted average based on all malts in the bill.

For your example, 23.5 is 97.9% of the grain bill, and 0.5 is 2.1%. Multiply their respective PPG values times each percentage, and add the resulting products. You'll get 36.958 PPG as the potential for the whole grain bill.

37 x 0.979 = 36.223
35 x 0.021 = 0.735
36.223 + 0.735 = 36.958

@ScrewyBrewer or just use a general weighted average formula (without explicitly computing percentages first). Whichever is easier given your starting point.

(23.5 x 37) + (0.5 x 35)
------------------------
23.5 + 0.5

 

[ScrewyBrewer]

@ScrewyBrewer or just use a general weighted average formula (without explicitly computing percentages first). Whichever is easier given your starting point.

(23.5 x 37) + (0.5 x 35)
------------------------
23.5 + 0.5

Thank you but @McKnukle's approach was easy enough to do.

With strike water, sparge water, total brewing water volumes being the same and 80% mash efficiency ...

Using Daniel's advanced gravity calculation for the sample Pale Ale recipe gives:
1.055 pre-boil gravity and 1.061 original gravity for a 0.006 point difference.

While Doug's sheet gives:
1.052 pre-boil gravity and 1.058 original gravity for a .006 difference.

Is this in line with what others are getting?

 

[jdudek]

After tinkering with doug293cz's spreadsheet and following this and similar threads, most examples use 80% FGDB, 4% grain moisture content, 37 as the weighted grain potential and 100% conversion efficiency (ie: 80% mash efficiency). Is it safe to say that those are default values to be used in the majority of recipes?

Another question regarding a congress mash. Do I enter 36 ppg as the weighted grain potential for a recipe that uses 23.5 lbs of 37 ppg malt and 0.5 lbs of 35 ppg malt?

I was wrong in my original assertion in the post you quoted. When I said water boil off + absorption = total wort and not total water. It is indeed total water because grain absorption is understood to be apparent grain absorption (the difference between starting water and wort volume after bag removal) and not real absorption (the difference between wort before and after pulling the bag). Therefore my claim of extra 0.4L was incorrect. In any case, the spreadsheet handles this correctly.

 

[ScrewyBrewer]

I was wrong in my original assertion in the post you quoted. When I said water boil off + absorption = total wort and not total water. It is indeed total water because grain absorption is understood to be apparent grain absorption (the difference between starting water and wort volume after bag removal) and not real absorption (the difference between wort before and after pulling the bag). Therefore my claim of extra 0.4L was incorrect. In any case, the spreadsheet handles this correctly.

I'm afraid you've lost me, I was really focusing on the 4% moisture content...

 

[jdudek]

I'm afraid you've lost me, are you referring to a different post?

You have quoted me in an earlier post today.

 

[ScrewyBrewer]

You have quoted me in an earlier post today.

Yes, thank you. I see now where the confusion may have started.

I referenced your quote but was actually focused more on the parameters relating to 80% FGDB, 4% grain moisture content and 100% conversion efficiency (ie: 80% mash efficiency) as being default values.

After some tinkering, with strike water, sparge water, total brewing water volumes being the same and using 80% mash efficiency I get the following results. I am wondering if the discrepancies are in line with what others are getting?

Using Daniel's advanced gravity calculation for the sample Pale Ale recipe gives:
1.055 pre-boil gravity and 1.061 original gravity for a 0.006 point difference.

While Doug's sheet gives:
1.052 pre-boil gravity and 1.058 original gravity for a .006 difference.

 

[McKnuckle]

@ScrewyBrewer after some careful reverse engineering, I have got Brewfather and Doug's spreadsheet in sync within one gravity point, at least up until the OG gets very high as is described above. What is the sample pale ale recipe and what is Daniel's advanced gravity calculation that you reference?

 

[ScrewyBrewer]

@ScrewyBrewer after some careful reverse engineering, I have got Brewfather and Doug's spreadsheet in sync within one gravity point, at least up until the OG gets very high as is described above. What is the sample pale ale recipe and what is Daniel's advanced gravity calculation that you reference?

It's a simple Pale Ale recipe using 23.5 lbs of 37 ppg Pale Ale malt and 0.5 lbs of 35 ppg Crystal 10 malt. In all honesty, at second glance the Daniels formula relates more to ABV%.

The SG calculation uses
grain weight * ppg / post boil volume * mash efficiency

where

23.5 * 37 / 11.75 * .80 = 59.20
00.5 * 35 / 11.75 * .80 = 1.19

and OG = 59.20 + 1.19 = 1.061

 

[McKnuckle]

For one thing, you can't use post-boil volume for a mash efficiency calculation. Mash efficiency evaluates wort collection at the pre-boil stage. The "gallons" in points per pounds per gallon are of wort during the mash. So the volume in that equation will be a higher value, and the division portion will yield a smaller figure, yielding a lower efficiency value.

What are the water volumes you are entering into Brewfather? I'll try it as well.

 

[ScrewyBrewer]

For one thing, you can't use post-boil volume for a mash efficiency calculation. Mash efficiency evaluates wort collection at the pre-boil stage. The "gallons" in points per pounds per gallon are of wort during the mash. So the volume in that equation will be a higher value, and the division portion will yield a smaller figure, yielding a lower efficiency value.

What are the water volumes you are entering into Brewfather? I'll try it as well.

Thank you.

Pre-boil = 13 gallons
Post boil = 11.75 gallons
Strike water = 12 gallons
Sparge water = 2.80 gallons
To Fermentor = 10.50 gallons

 

[jdudek]

Also keep in mind that your grain has 4% water. Therefore your dry grain is not 23.5 lbs but rather 23.5*0.96=22.56.

22.5*37/13*0.8 = 51. Closer to doug’s spreadsheet (52)

 

[McKnuckle]

First make sure your value for boil expansion is set to 0%.

When I enter values to match your volumes at each stage and the grain bill, I have both tools matching when Grain Moisture Weight is set to zero in the spreadsheet:

Pre-Boil SG = 1.060, OG = 1.066

This is with conversion efficiency in the spreadsheet set to 100%, which produces mash efficiency of 87.6%, which I then go into Brewfather and match.

And in the spreadsheet only, when moisture is set to 4%, it lowers the efficiency slightly to 87.3%, producing:

Pre-Boil SG = 1.057, OG = 1.063

 

[ScrewyBrewer]

@McKnuckle thank you for following up and for pointing out the error in the previous SG calculation. I now get the total point potential to match Doug's spreadsheet using an 80% mash efficiency / 91% conversion efficiency and using what I consider to be default values of 4% moisture content and 80% fine grind basis potential.

The modified SG calculation now uses
grain weight * moisture content * ppg / pre-boil volume

22.56 * .96 * 37 / 13 = 64.209
0.5 * .96 * 35 / 13 = 1.29
and 64.209 + 1.29 = 65.502
total point potential = 65.502 * 13 = 852 total point potential
pre-boil gravity = 1.052
post-boil gravity = 1.058 (@ 680 points recovered)
6% ABV with 75% yeast attenuation

 

[Wolffie]

Wow!! I would really like to sample any one of your brews ( McKnuckle, Jdudek, Vikeman, ScrewyBrewer ) I thought my brew was good but what a difference I have to look forward to with all this knowledge at hand. Also thanks to BF (skarp0ye) Hearing the knowledge of concerns from you all. I enjoyed this thread and am sure all others did.
Drink up and be Merry!
Happy Holidays

 

[McKnuckle]

Cheers @Wolffie and best wishes.

Knowing a bit of brewing math won't produce good beer. But it's enjoyable to understand what's going on, and that helps us aim for a particular end product.

I think for me, understanding leads to consistency which gradually dials out the "oops" factor, leading to predictability and confidence. I definitely make a few sub-par beers among the really good ones, but it's due to poorly constructed recipes rather than process/technique. And that's how it should be, I think.

 

[Wolffie]

Cheers @Wolffie and best wishes.

Knowing a bit of brewing math won't produce good beer. But it's enjoyable to understand what's going on, and that helps us aim for a particular end product.

I think for me, understanding leads to consistency which gradually dials out the "oops" factor, leading to predictability and confidence. I definitely make a few sub-par beers among the really good ones, but it's due to poorly constructed recipes rather than process/technique. And that's how it should be, I think.

I agree with what you say (Knowing a bit of brewing math won't produce a good beer)!! I would still bet on all of you guys brews a greater % of times and all knowledge and help you all offer members. With out the math and and willingness to share where would one start?
Credit given where credit due is a motto I share. Thanks again

 

[storunner13]

FWIW, BrewCipher asks the user for mash efficiency for a given recipe. Using that, in conjunction with the user's brewhouse parameters (e.g. mash tun dead space, xfer losses, boil off rate, etc.), its mash efficiency predictor tool calculates an expected mash efficiency for any size grain bill and/or a change from batch sparge to no-sparge or vice versa.

I agree that conversion efficiency is definitely key. But, as you mentioned, most users don't know their conversion efficiency (or often, even what that means). The math can derive the conversion efficiency behind the scenes, given grain bill size, mash efficiency, and brewhouse parameters.

That said, for educational purposes, I would take Doug's stuff before all others.

Reviving this briefly, to agree with @VikeMan and add my $.02 regarding mash efficiency calculators and conversion efficiency. I'm a little frustrated that none of the popular calculators have conversion efficiency as a variable, and resulting First Wort gravity estimate. With so many people moving to BIAB and no sparge systems, this seems like a big miss in the calculators. Having to adjust my mash efficiency up for low gravity beers and down for high gravity beers is a PITA. In my perfect world, I could set conversion efficiency to 97%, and then target the right first wort gravity for my boil off. Grain absorbtion, dead space, and other mashtun losses are basically fixed, so no-sparge systems should have mash efficiency calculated from conversion efficiency.

I see that Brewfather has added "conversion efficiency" as a an "Experimental Feature". Does anyone know if this affects anything? As far as I can see, it doesn't impact any values in recipe creation, and the description which says it "allows you to ... track first wort gravity" also doesn't seem to be implemented. Is there any plan to get this added? At the very least, if there's a calculator for "first wort gravity" on the recipe creation page, I can adjust my mash efficiency to get to the right first wort gravity for full volume mashes.

 

[ScrewyBrewer]

Agreeing with @VikeMan, entering mash efficiency and thickness as variables is enough information to calculate lauter, conversion, and brewhouse efficiencies. The frustrating part is what one calculator calls brewhouse efficiency is called conversion efficiency in another calculator and efficiency in some others.

 

[jdudek]

Reviving this briefly, to agree with @VikeMan and add my $.02 regarding mash efficiency calculators and conversion efficiency. I'm a little frustrated that none of the popular calculators have conversion efficiency as a variable, and resulting First Wort gravity estimate. With so many people moving to BIAB and no sparge systems, this seems like a big miss in the calculators. Having to adjust my mash efficiency up for low gravity beers and down for high gravity beers is a PITA. In my perfect world, I could set conversion efficiency to 97%, and then target the right first wort gravity for my boil off. Grain absorbtion, dead space, and other mashtun losses are basically fixed, so no-sparge systems should have mash efficiency calculated from conversion efficiency.

I see that Brewfather has added "conversion efficiency" as a an "Experimental Feature". Does anyone know if this affects anything? As far as I can see, it doesn't impact any values in recipe creation, and the description which says it "allows you to ... track first wort gravity" also doesn't seem to be implemented. Is there any plan to get this added? At the very least, if there's a calculator for "first wort gravity" on the recipe creation page, I can adjust my mash efficiency to get to the right first wort gravity for full volume mashes.

I've not managed to get the conversion efficiency do anything in brew father. Looks like a field that does nothing right now, similar to the grain moisture field. I'm in the same boat as far as frustration with calculators. In the end I use my own calculator to figure out what the efficiency will be and then plug that into brew father.