Help maths not working

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Canarybeer

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I have a grainfather and am fairly new to it.

I throw away as much as I drink through stupid mistakes !

I am struggling to understand water amounts.

Take the kentish Amber ale. Its says the following:

Mash water 17.94L

Sparge water 16.57L

Boil size – 28.96L

Batch size 23L

My maths isn’t working here.

4.6kg of grain will absorb approx. 4.6L water

That means that approx. 13.34L will be left at sparge.

I don’t know if there are any losses from the sparge water but assuming not because the grain is already saturated.

The receipe says to add 16.57L for sparge

Therefore we have 29.91 L pre boil ???? That’s not 28.96 as listed??

If we go with 28.96L preboil I am told 8% will boil off. That’s leaves 26.64L to go to FV ??? That’s not 23L ???



Then using Grainfathers directions not the receipe it’s the same story.

They say Grain weight in kg (4.6kg) x2.7 + 3.5 That equals 15.92 mash volume

Once again grain absorption = 4.6L

Then it says Sparge water (24L + Grain 4.6kg) x 0.8 = sparge water in L So that’s 22.8L ????

If you add up 15.92 mash water less 4.6L for absorption that equals 11.32. You then add 22.8L of sparge and you get 34.12L ???

The grainfather wont hold that amount???

Even if you could boil 34.12L with a 8% boil off you end up with 31.39 Batch size



My sums are wrong somewhere ??
 

Linalmeemow

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Use the Grainfather recipe calculator on the Grainfather website, problem solved.
 

cushyno

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As well as water absorbed by the grain you'll lose some to evaporation during boil off. While I don't have a grain father I get about 2.5L boil off over 60 mins, the principle is the same. I imagine grainfather also has some kettle losses - the amount of wort you can't drain off due to pickup height and pipework.
 

Horners

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I have a grainfather and am fairly new to it.

I throw away as much as I drink through stupid mistakes !

I am struggling to understand water amounts.

Take the kentish Amber ale. Its says the following:

Mash water 17.94L

Sparge water 16.57L

Boil size – 28.96L

Batch size 23L

My maths isn’t working here.

4.6kg of grain will absorb approx. 4.6L water

That means that approx. 13.34L will be left at sparge.

I don’t know if there are any losses from the sparge water but assuming not because the grain is already saturated.

The receipe says to add 16.57L for sparge

Therefore we have 29.91 L pre boil ???? That’s not 28.96 as listed??

If we go with 28.96L preboil I am told 8% will boil off. That’s leaves 26.64L to go to FV ??? That’s not 23L ???



Then using Grainfathers directions not the receipe it’s the same story.

They say Grain weight in kg (4.6kg) x2.7 + 3.5 That equals 15.92 mash volume

Once again grain absorption = 4.6L

Then it says Sparge water (24L + Grain 4.6kg) x 0.8 = sparge water in L So that’s 22.8L ????

If you add up 15.92 mash water less 4.6L for absorption that equals 11.32. You then add 22.8L of sparge and you get 34.12L ???

The grainfather wont hold that amount???

Even if you could boil 34.12L with a 8% boil off you end up with 31.39 Batch size



My sums are wrong somewhere ??

Dunno about your GF sparge formula - looks totally wrong but on your first working, you have taken no account of dead space (c2.5L) or hop absorption.
 

Canarybeer

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Dunno about your GF sparge formula - looks totally wrong but on your first working, you have taken no account of dead space (c2.5L) or hop absorption.
Calculations were from grainfather manual that came with it good point about hops but isnt going to be litres is it
 

Canarybeer

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As well as water absorbed by the grain you'll lose some to evaporation during boil off. While I don't have a grain father I get about 2.5L boil off over 60 mins, the principle is the same. I imagine grainfather also has some kettle losses - the amount of wort you can't drain off due to pickup height and pipework.
Thanks for your reply I have allowed 8% for boiloff but still too much left. Please read my sums afain
 

PhilBrew

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Horners

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Ps what is dead space
Dead space is the space below the pump outlet. So once you have finished draining to FV there will be a load of liquid and trub left in the GF.

On the GF calculation, in my manual sparge is determined using the following formula:

(Final Volume plus Water loss in boil and trub) - Mash Water volume + (grain bill in kg x 0.8)

For an hours boil they reckon boil off plus trub = 5L so for 23L in the FV that should give:

28L- 17.94 (mash) +3.68 = 13.74L of sparge

or if you take the GF mash calculation of 15.92 the sparge would come out at 15.76 L as per Philbrews calculation. Total water volume is the same in both cases.
 

PhilBrew

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Then it says Sparge water (24L + Grain 4.6kg) x 0.8 = sparge water in L So that’s 22.8L ????
.... TBH, that doesn't look like all of the calculation for sparge water ... sparge water calculations often calculate total water and subtract the mash water, and that looks like only the first part of calculating total water, even ... erm, this may be a long shot, but were those instructions for that calculation at the bottom of a page in the manual, have you tried turning the page :confused.:

Cheers, PhilB
 

Zephyr259

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Dead space is the space below the pump outlet. So once you have finished draining to FV there will be a load of liquid and trub left in the GF.

On the GF calculation, in my manual sparge is determined using the following formula:

(Final Volume plus Water loss in boil and trub) - Mash Water volume + (grain bill in kg x 0.8)

For an hours boil they reckon boil off plus trub = 5L so for 23L in the FV that should give:

28L- 17.94 (mash) +3.68 = 13.74L of sparge

or if you take the GF mash calculation of 15.92 the sparge would come out at 15.76 L as per Philbrews calculation. Total water volume is the same in both cases.
This sounds right and like what I do. (Grain weight X 2.7) +3.5 for the mash. Then sparge is 28 - mash volume + (0.8 X grain weight). If measured when cold that volume will gain about 1L when boiling so your pre-boil will be around 29L, post boil around 26L which gives 23L of cooled wort in the FV and 2L dead volume below the pump and in trub. Having said that, I tip the GF to suck out more so tend to get 1-1.5L DV m
 
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