Large Batches

[meathead]

Is it good practice to use the grain bill required for a 30 litre batch but the water required for a 15 litre batch and dilute later to get back to the 30 litre batch?

Reason I want to do this is because I have a Grainfather and a Fermentasaurus.

If I transfer 30 litres of wort to Fermentasaurus it weighs 30 kg so not good to move.

Also I have 15 litre cubes if I want to no chill.

My gut tells me this is all good, but I was wondering what the potential downside might be?

 

[mtb]

Your main concern would probably be the low liquor to grain ratio in the mash, resulting in poor mash efficiency. You could adjust for that by batch sparging with 8 - 10L and topping up in the FV as you suggested.

Care to not over-sparge though, as it runs the risk of extracting unwanted tannins. Someone with experience in that area can elaborate, I typically sparge with just a few litres.

 

[mofox1]

I'm not a grainfather owner, but I reckon you'd be pushing it. As 9kg appears to be the grain limit for the Grainfather (from my *very* quick google search), and as it is at capacity I don't think you'd get the efficiency to get 30L of normal strength beer out of it. Assuming you are targeting 1.040 into the fermenter, that is 1.080 in the cube... something I don't see happening w/o some sugar additions to the kettle.

I'd just go two separate brews into your 15L cubes and combine in the fermenter... might take longer but it will be much less painful.

FWIW - My over gravity brews tend to be a 16L cube + 4L water for a 20L fermenter volume into a 19L keg with no leftovers. I don't tend to do them for stronger brews... usually just the ~5% range targeting a post-boil gravity of 1.050 - 1.060 to dilute down to 1.040ish. Easy peasy.