Brewfather mash water calculation

[Birdsnestbrewery]

I am struggling to understand where brewfather is getting it's numbers from.
It's telling me
Mash 15.4L
Sparge 15.27L
Total 30.67L
Boil bol 26.19L
In other words from the total mash and sparge I lose 4.48L.
My grain bill is 5.76 kg (of which 95.5% is maris otter) and the grain absorption rate is 0.96kg/L with 1L mash tun dead space. So I figure I should lose 6.5L not 4.48.
Any clues?

 

[foxy]

I am struggling to understand where brewfather is getting it's numbers from.
It's telling me
Mash 15.4L
Sparge 15.27L
Total 30.67L
Boil bol 26.19L
In other words from the total mash and sparge I lose 4.48L.
My grain bill is 5.76 kg (of which 95.5% is maris otter) and the grain absorption rate is 0.96kg/L with 1L mash tun dead space. So I figure I should lose 6.5L not 4.48.
Any clues?

I would say no two brewers lose the same to grain absorption, did you put your figures into Brewfather? If not it is just taking a punt at your loss. My loss is around 0,75litres / kilo, if you know your loss just factor it in to the Brewfather calcs.

 

[Birdsnestbrewery]

Sorry that's not my point. I am just struggling to understand the theory it's using. This all theoretical at the moment.
The numbers I quoted are from Brewfather assuming 0.96 l/kg, and I am doing the same calculation myself. But it's clearly not doing what I thought.

 

[foxy]

Sorry that's not my point. I am just struggling to understand the theory it's using. This all theoretical at the moment.
The numbers I quoted are from Brewfather assuming 0.96 l/kg, and I am doing the same calculation myself. But it's clearly not doing what I thought.

You have to use your own figures, work out your loss to grain then type them in to the Brewfather app. Maybe Brewfather is calculating dead space at 2 litres? Dead space is the space below the bottom of the tap, some calculate dead space as below the mash tun or false bottom.

 

[Rodcx500z]

Have you set your kettle profile

 

[dmtaylor]

I am struggling to understand where brewfather is getting it's numbers from.
It's telling me
Mash 15.4L
Sparge 15.27L
Total 30.67L
Boil bol 26.19L
In other words from the total mash and sparge I lose 4.48L.
My grain bill is 5.76 kg (of which 95.5% is maris otter) and the grain absorption rate is 0.96kg/L with 1L mash tun dead space. So I figure I should lose 6.5L not 4.48.
Any clues?

Your numbers look right to me.

Every time I see someone mention the Brewfather calculator, I do a facepalm. I don't have a Brewfather but I see nothing but errors with it.

Since you are right and the software is a little off, I would add the extra 2L you need to your mash/strike water and call it good / close enough.

 

[Birdsnestbrewery]

You have to use your own figures, work out your loss to grain then type them in to the Grainfather app. Maybe Grainfather is calculating dead space at 2 litres? Dead space is the space below the bottom of the tap, some calculate dead space as below the mash tun or false bottom.

It's brewfather app not Grainfather.
The mash tun dead space is set in that app to 1L. It seems like it's not using that or the absorption value in the app.

 

[Birdsnestbrewery]

Your numbers look right to me.

Every time I see someone mention the Brewfather calculator, I do a facepalm. I don't have a Brewfather but I see nothing but errors with it.

Since you are right and the software is a little off, I would add the extra 2L you need to your mash/strike water and call it good / close enough.

Thanks. It would be nice if the recipe values were usable though!
By the way you said "I don't have a brewfather". Maybe you're thinking of Grainfather. Brewfather is just the website & app as far as I know.

 

[foxy]

It's brewfather app not Grainfather.
The mash tun dead space is set in that app to 1L. It seems like it's not using that or the absorption value in the app.

Sorry Brewfather, looks like it isn't accounting for dead space, if it did it would only be 0,02 litres out.

 

[Caramel Ox]

The mash tun dead space is the total volume below the grain. This has to be added to the 3l/kg strike water calculation otherwise the water level may be below the top of the grain. You don’t lose the dead space volume unless you have no way to extract it.

I think the other reason for the number discrepancy is that the boil volume is “hot” so you can reckon against your kettle size and boil over risk, whereas your strike and sparge waters are measured cold.

 

[DuncR]

Give it a go and see what happens!

 

[Mash Monster]

Stupid question
What equipment profile are you using in Brewfather?

 

[foxy]

The mash tun dead space is the total volume below the grain. This has to be added to the 3l/kg strike water calculation otherwise the water level may be below the top of the grain. You don’t lose the dead space volume unless you have no way to extract it.

I think the other reason for the number discrepancy is that the boil volume is “hot” so you can reckon against your kettle size and boil over risk, whereas your strike and sparge waters are measured cold.

The dead space is the volume below the tap, the space below the grain bed is the volume of liquor which has to be added to the mash liquor volume as a correction. That volume is recovered, so not in a dead space in the true sense of the meaning.

 

[Mash Monster]

The dead space is the volume below the tap, the space below the grain bed is the volume of liquor which has to be added to the mash liquor volume as a correction. That volume is recovered, so not in a dead space in the true sense of the meaning.

I’m sure you are correct. However I use a Dark farm Brew Tank and rely on Brewfather for my calculations
The dead space below the tap is about 2L or so but the space below the grain basket is a whopping 10L. Brewfather counts this 10L as ‘dead space’ in its calculations otherwise I would be lucky to cover the grain in the basket if I set my dead space to 2L
Hence my question as to what profile the OP was using

 

[foxy]

I’m sure you are correct. However I use a Dark farm Brew Tank and rely on Brewfather for my calculations
The dead space below the tap is about 2L or so but the space below the grain basket is a whopping 10L. Brewfather counts this 10L as ‘dead space’ in its calculations otherwise I would be lucky to cover the grain in the basket if I set my dead space to 2L
Hence my question as to what profile the OP was using

As most aps do, the reason being is you would be short on the mash volume if you didn't, but you don't lose the 10 litres. True dead space is the amount which you will lose when transferring to the fermenter. I have a dip tube so my volume is greater than below the tap though I do collect the wort that is left and reheat it and bottle it or add it to the fermenter later. So the losses are, absorption, boil and the remainder in the kettle.

 

[dmtaylor]

Thanks. It would be nice if the recipe values were usable though!
By the way you said "I don't have a brewfather". Maybe you're thinking of Grainfather. Brewfather is just the website & app as far as I know.

Ah. I don't have either one. It's the software I hear complaints about. The Grainfather system probably works great, I think I have some friends using it.

 

[Braumeister]

Brewfather is actually a very good piece of software, I’ve used it a lot. I don’t know why anyone would criticise it, it’s not for everyone and not perfect, but it is very customisable and user friendly.

 

[Birdsnestbrewery]

I tend to agree that brewfather is a good piece of software.
So I did the brew and adjusted the numbers in BF with what I actually got.
I think that it is not including the mash tun dead space in the water absorbed, but that is included in the mash water amount.
In actual fact I get very little mash dead space because I use a pipe manifold rather than a false bottom, and the grain goes all the way down.
I think I have it figured out, I will see if it works out next time.