Grainfather Water Volumes

Does the GF water calculator account for any loss due to absorbance by hops?

I keep coming up short in the FV volume.
Last brew my pre-boil volume was spot on. but I was 2L short in the FV.

I read somewhere that you lose some wort due to hop absorption.
It was an American forum and they quoted 0.11 gallons per ounce of hops.
(0.42L per 28g of hops)

This is about the shortfall I got with my last brew, which had 112g of hops (1.68L)

Thanks!

I use pellets and going with the Grainfather website calculator, it works out about right into the fermenter.
Another thing I noticed, if I finish my boil when the measurements on the side of the GF are 2 litres above my desired volume into the FV, then it's about right.
So I normally do 12 litre batches so if my boil is finished at 14 litres then it's 12 litres in the FV.

Used the online Grainfather Recipe creator with my latest brew using the new connect controller. Wanted 24l for the FV, and ended up with 23.5 so not too far out. Used hop leaves.

Hmmm, must be just me then.
Last brew I had post-boil volume of 22.5L
Was aiming for 20L in the FV, and I ended up with 18L
4.5L lost - I must be doing something wrong.

The default boil time is 60 mins on the online calculator, you do change that if you boil for 90 mins?

shepp said:

The default boil time is 60 mins on the online calculator, you do change that if you boil for 90 mins?

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It was a 60 min boil, and the volume post boil looked about right. I had just under 22L post boil, and was aiming for 20L in the FV.

I think my problems are losses in the transfer to the FV

Ended up with 18L in the FV, and actually didn't look like a lot of liquid left in the bottom of the GF when I poured the hops and stuff into the compost bin.

Could it just be something simple like inaccurate volume markings on the FV bucket?

Next brew I will try and be more methodical and record exact volume left in the bottom of the GF.

Also, does anyone else have a load of wort left in the chiller when they have finished transferring to the FV? I seemed to have a load left that came through when I was cleaning.

MagnusTS said:

It was a 60 min boil, and the volume post boil looked about right. I had just under 22L post boil, and was aiming for 20L in the FV.

I think my problems are losses in the transfer to the FV

Ended up with 18L in the FV, and actually didn't look like a lot of liquid left in the bottom of the GF when I poured the hops and stuff into the compost bin.

Could it just be something simple like inaccurate volume markings on the FV bucket?

Next brew I will try and be more methodical and record exact volume left in the bottom of the GF.

Also, does anyone else have a load of wort left in the chiller when they have finished transferring to the FV? I seemed to have a load left that came through when I was cleaning.

Click to expand...

Yes that's worth checking, my Young's 25litre FV markings are 1 litre under what the actual amount is at 15 litres.
You could go for a 70 or 80 min boil and just stop when you reach 2 litres above the amount you want in your FV. Maybe a bit more if you use loose hops.

I use pellets, I cool it to 80 degrees in the kettle before adding the flameout hops and then whirlpool it really well, then I let it sit 15mins so it really settles well, when I transfer over to the FV there is very little beer getting left and a nice cone in the middle of the Grainfather, looks like a little volcano, this sort of flattens out as you get the last of it out, I watch what is coming out of the RFC rather than what is going in as there is fair volume here to be gained, maybe 0,5 litre and lets face it, if a little trub makes it over is it a really big deal? My beer almost always turns out clear, even the Punk IPA type heavily hopped ones, but thats down to a gelatin and severe cold crashing routine.

Brett74 said:

My beer almost always turns out clear, even the Punk IPA type heavily hopped ones, but thats down to a gelatin and severe cold crashing routine.

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Thanks Brett, good Grainfather advice.

I'd also like to hear more about your gelatine and cold crashing....

How long are you leaving the pump on for to get it in to the fv? It'll slow to a trickle near the end but it'll keep going for another litre or two.

How long are you leaving the pump on for to get it in to the fv? It'll slow to a trickle near the end but it'll keep going for another litre or two.

DoctorMick said:

How long are you leaving the pump on for to get it in to the fv? It'll slow to a trickle near the end but it'll keep going for another litre or two.

Click to expand...

I stopped when the outflow slowed to a trickle. The liquid going in to the cooler became foamy with air and I was worried that I might be damaging the pump.

But this might explain my shortfall, and the amount of wort left in the cooler.

Next time I will leave it going for longer and see if I get nearer my target volume.

Thanks!

its a magnetic drive pump so there's no physical connection between the impeller and the motor. I leave mine running to a trickle then i tip the grainfather to get the last litre or so. I'm always within maybe 500ml of target volume

Pawlo7671 said:

its a magnetic drive pump so there's no physical connection between the impeller and the motor. I leave mine running to a trickle then i tip the grainfather to get the last litre or so. I'm always within maybe 500ml of target volume

Click to expand...

I did this with my 2nd brew and got within 500ml. 1st brew I was over 1.5 litres under so it certainly makes a difference.:thumb:

Pawlo7671 said:

its a magnetic drive pump so there's no physical connection between the impeller and the motor. I leave mine running to a trickle then i tip the grainfather to get the last litre or so. I'm always within maybe 500ml of target volume

Click to expand...

I do the same.

Brew #3 and I did what you guys recommended. I left the pump running even when the flow into the FV had slowed to a trickle. There was a mass of foam in the pipe as it went into the chiller, but wort kept trickling out into the FV. I didn't have the chiller on top of the GF this time so I could see what was going on inside. And I also tilted the GF toward the pump as the level dropped. It was awesome; I watched as the pump sucked the GF dry. I had used pellets this time and the liquid was sucked out of them even though the filter was completely covered in green pellet sludge. All I was left with was a pile of damp pellet mess. Brilliant.

So final volumes were much much better this time. I was aiming for 20L in the FV. I had 22.75L post-boil (but think I lost a little more during the 20min hop stand when I forgot to put the lid back on). But ended up with a whopping 21.5L in the FV !! Not sure how that happened. It was a new FV (Youngs wide neck), and I think I need to check the calibration of the volume markings, but I am very happy with how this turned out. So a big hats off to you guys on this forum for solving my volume problems. Thanks folks.

Another top tip that came from this forum was to use starsan to make grain basket assembly less sweary. Those blinking plastic seals just kept on peeling off the mesh disk. But a quick squirt of strain inside the basket and they slid in as nice as anything, no messing, no swearing. Thank you whoever suggested that.