Grainfather metric water formulas

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festbier

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I am wondering if anyone has the metric formulas for calculating mash and sparge water for the Grainfather. One of their videos had the sparge water calc only, and not the mash water calc.

There seems to be some discrepancy in the formulas. I have seen, volume in liters, (2.2 x kg grain) + 3.5L , and (2.7 x kg grain) + 3.5L

I would just like to see something official from Grainfather.
 
The calculator is wrong. I want the formulas. Of course, I could use the US version and convert gallons to liters, but I want to compare the results using each formula.
 
Hmmmmm how do you figure the website calculator is wrong?

The Grainfather users Facebook page recommend its use....many use Beersmith to formulate the recipe but use the website calculator for Mash & Sparge amounts.

Cheers Mark
 
festbier said:
The calculator is wrong. I want the formulas. Of course, I could use the US version and convert gallons to liters, but I want to compare the results using each formula.
Click to expand...

No. It really isn't.
I use it all the time - and hit all my numbers - apart fro mwhen i milled malted oats incorrectly.

If your concenred try the ap, you input your recipe and the water calcs come up in there as well - super easy.
 
Righto festbier.....how about a few examples now that you have the instructions direct from GF.

If the website is wrong as you say....then would love to get the right formula.

Cheers Mark
 
bruiserbbq said:
Righto festbier.....how about a few examples now that you have the instructions direct from GF.

If the website is wrong as you say....then would love to get the right formula.

Cheers Mark
Click to expand...

Wrong...the burden of proof is not on me. If you don't believe me, do your own research and report back to me by Monday.
 
The calculator is not wrong, I get the exact volume in my fermenter every time, almost every weekend.

I was told there was once a bug with the calculation on the mobile app, but it was fixed, a long time ago.

Straight out of the instructions included with my GF;
Mash volume = (Grain weight in kg x 2.7) + 3.5
Sparge volume = (preboil volume - mash volume) + (grain bill in kg x 0.8)

The preboil volume for a 60min boil is 5l more than your batch volume.

In the case of a < 4.5kg grain bill you add extra water to the top plate and remove that from the sparge volume.

So in the case of a 21l batch of 5kg with a 60 minute boil;
Mash = (5 x 2.7) + 3.5 = 17l
Sparge = (26 - 17) + (5 x 0.8) = 13l

This is exactly the same as the online calculator.

If the proof is a burden not on you to justify your loose claims then I'm in agreement with bruiserbbq.
 
I came upon this by searching for the same answer as the OP. It seems as though the metric formulas match the online metric calcs, but the imperial numbers are not the same as the formula in the instructions.
Does anyone know which is correct for the imperial numbers (online calc vs formula)?
 
festbier said:
Wrong...the burden of proof is not on me. If you don't believe me, do your own research and report back to me by Monday.
Click to expand...
Actually if you come on here and say something is incorrect the burden of proof IS on you to support your claim.

If you want any credibility here then support your claims with proof.
 
Bumping my question so it's not hidden behind the argument


Does anyone know which is correct for the imperial numbers (online calc vs formula)?
 
They're similar with a lower grain bill, but the more grain you add, the more the two diverge.

Example: 19 lbs grain

Formula: 7.36 gallons mash / 1.94 gallons sparge
Calculator: 6.16 gallons mash / 2.98 gallons sparge (90 min)
Calculator: 6.16 gallons mash / 2.72 gallons sparge (60 min)

Big difference that will affect conversion, ph, extraction, etc.
 
Can you explain your formula?
and show a screenshot of the calculator? (just the 60 or 90 will do, as 60/90 mins will differ for boil off anyways.
 
No problem. These are straight from a US manual I found online. My GF is arriving today, so I suppose there's a chance the manual I get with it will have been updated with different formulas. I was trying to get as much prepared as I could before it got here.

Mash
(Grain weight in lb x 0.34) + 0.9 US Gal
Example for 12 lbs -- (12 x 0.34) + 0.9 = 4.98 US Gal

Sparge
(7.4 - mash water volume in US Gal) + (grain bill in lb x 0.1)
Example for 12 lbs -- (7 .4 - 4.98) + (12 x 0.1) = 3.62 US Gal
7.4 is pre-boil volume

GF.jpg
 
That is a little odd.
AS I'm metric I use a slightly different formula, and my volumea are pretty close

the metric formula is
(grain weight x2.7) +3.5 = Mash volume
I cant remember the Sparge volume calculatation.

If it was me I'd work on 73-74% efficiency, and use the Grainfather calculator to start with, then adjust from there. You'll get an idea of what is needed soon after that as you get some consistency.

but check the book ,as it might say something slightly different, I'm pretty sure they adjusted the calculators awhile back so it could be that.
 
EDIT: I've just worked out the sparge calcs, and I would suggest your pre-boil volume is too high. thats why your calcs are out.
the online mash calculator is good, but your sparge is out.
 
Just to be clear for future readers... the "out" calc is straight from the GF manual formula (still in the manual I received). The online is good.

So go with the online calc?
 
I'd start there, as you can adjust accordingly from there. Because your online mash calc is good, it works, and i believe that is the correct way to go.
check the book when you receive it, to check for any changes.
If your concerned about the Sparge information being too high you could use the calculation or the online, or split the difference.

but if it was me, i'd start with the online calc, then if your numbers are out, adjust your sparge water slightly and brew the same beer again.

when i got the machine, i brew the same beer twice to get the numbers dialled in (not on the same day) my first brew came in 2-3 point under OG, so i adjusted for the next one by about half a litre and hit my numbers.


also I'd suggest downloading beersmith (if you haven't already, and down load the beersmith grainfather profile, which is available (i think) from the grainfather users group on facebook.....
 
Crusader,
Thanks. I do have Beersmith. Trying to set up the profile is what led me to post the question here to begin with. I can't seem to get it set up correctly. I understand most folks are using it for recipe formulation, and the online calculator for the water volumes.

I applied for the NA Grainfather group, but I guess I haven't been accepted yet.

Thanks again.
 
festbier said:
I am wondering if anyone has the metric formulas for calculating mash and sparge water for the Grainfather. One of their videos had the sparge water calc only, and not the mash water calc.

There seems to be some discrepancy in the formulas. I have seen, volume in liters, (2.2 x kg grain) + 3.5L , and (2.7 x kg grain) + 3.5L

I would just like to see something official from Grainfather.
Click to expand...

It seems like your questioning standard math do it for yourself its not hard.
 
IchLiebeBier said:
Crusader,
Thanks. I do have Beersmith. Trying to set up the profile is what led me to post the question here to begin with. I can't seem to get it set up correctly. I understand most folks are using it for recipe formulation, and the online calculator for the water volumes.

I applied for the NA Grainfather group, but I guess I haven't been accepted yet.

Thanks again.
Click to expand...

what is this NA gf group? Where is this crusader? I assume your Christian, simply by the word Crusader, high charge world.
 

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