Max Grainfather batch size?

[Fore]

I'm trying to get my head around this. I'm probably thinking about it the wrong way.

I'd always aim to get the most wort I could from each brewday, while keeping the grain bill below a practical 8kg. If I'm thinking about this correctly, I see the 8kg as a secondary limit only when brewing a high ABV beer; i.e. when your default target batch size leads to the grain bill exceeding 8kg, you'd have to start dialing back on the batch size. Whereas the maximum target batch size the Grainfather can accommodate, would most often be the starting factor in my recipe calculations. Am I coming at this from the wrong angle? The Grainfather website allows you to enter any batch volume, which doesn't help my understanding.

 

[MyQul]

Whilst I dont own a GF so dont know te max amount of grain you can fit in there. But I think you're thinking about it in the correct manner. I have/had a similar thing with my 18.5L pot, in that the max grain I could get in their was about 5.2kg. Having a max amount of grain for your boiler means that either you can do a maximum batch size for your 8kg of grain or you can do a bigger batch size (but lower OG) by simply diluting your wort in the FV. You can also do a smaller batch size but higher OG (than your usual max batch size) but I dont know if this is an option with a GF, but is with BIAB

Another little tweek you can do is by doing a thicker mash to get a little bit bigger batch.

 

[Fil]

liquoring back to increase the volume and dilute the strength is the only way to overcome the limitation of the boil kettle volume.
you could with minimal extra kit grainbag and coldbox, squeeze a 2nd brew into the session, perform a longer mash in the coldbox while you brew one brew in the g/f to completion, then drain and dunk or batch sparge the cold box and grain bag into the kettle for a 2nd boil..

 

[aamcle]

Look up reiterating mashes.

Aamcle

 

[Fore]

Thanks for the replies. A bit more digging and I think I got the answer I was looking for. I believe 25L is the standard brewday max batch size you would aim for with the Grainfather. I watched some videos with that brew length, and it was pretty close to the top on the boil.

On a different subject, the grain bill max is stated to be 9kg, but efficiency drops off quickly after 7.5 kg.

 

[Zephyr259]

You found the 25L figure I was about to give you, assuming an hour boil the GF loses about 3 L and has 2L dead volume below the pump so if you brim it to 30L pre-boil you can get 25L in the FV. I've never tested the grain capacity of mine yet as I do 15L batches as standard, and mostly 3 - 4 kg of grain. Given that volume I had an efficiency hit at 6.25 kg of grain hitting 1.082, for 66% efficiency. The next high OG beer, 1.070 target, I lowered the water ratio from 2.7L/kg to 2.3L/kg (+3.5L) and extended the boil to 90 mins and hit 78% efficiency giving me 1.072 OG. :-) My mash was a bit of a pain though, not sure if it was drawing air, running dry or getting stuck but I had to stir a few times as the recirc kept stopping. That ratio reduction is what GF suggested on one of their weekly blogs a while back and others use a flat 3L/kg and don't add on the extra volume.

 

[Slid]

I don't see any objection to continuing the sparge on a high mass grain bill batch and sparging into a large pot instead of the GF, Say another 5L that can be stove top boiled and added during the boil or even during the chilling process.
Only issue is balancing the grain tube over the pot. By happy coincidence it is possible to balance delicately on a Wilko 15L pot.

 

[aamcle]

If you start messing about with other vessels and the stove you might as well move on to trad 3V brewing all the advantage be a have gone down the drain.

Ora

 

[Slid]

If you start messing about with other vessels and the stove you might as well move on to trad 3V brewing all the advantage be a have gone down the drain.

Ora

A good point, that is.