Adding water post boil for 2 fvs

[Monkhouse]

Hi, I’m hoping to brew tomorrow and I’ve got 2 fvs, my mash tun is big enough for around 10kg of grain and I think my boiler is around 50litres.
I want to brew a strong wort to around 28litres and once the boil is complete add another 28litres of hot (boiled) water to the boiler then cool via plate chiller and transfer the 56litres of wort equally into the 2 fvs and then pitch one sachet of Nottingham yeast in one and a sachet of m41 belgian yeast in the other creating 2 full volume brews at around 6% abv each.
Does this sound feasible? And does anyone know how I’m supposed to input this idea into Brewfather so I can work out my recipe?
Any ideas on recipe would be good too,
My hops I have stored are:
Strata
Citra
Simcoe
Mosaic
Comet
Archer
Apollo
Magnum
Hallertau hersbrucker
Sorachi ace

 

[Caramel Ox]

As for how to setup- you edit your equipment profile to have a “fermenter top up”, do it all as if a single fv of the whole volume.

I would probably top up cold to save a heat and cool cycle.

Your efficiency will suffer with so much water left out, if you can get more water into the mash or sparge that would be better?

 

[Monkhouse]

The plan is to do an overnight mash to help with the efficiency. My mash tun is 40litres so could potentially do 31litres mash water then 39litres sparge but I’m not sure if the size of my boiler, possibly only 50litres.
I think what I’d do is sparge enough to max out my boiler then just top up any shortfall at the end of the boil say 10litres for example. This should work out better hopefully.
Any ideas on which hops to use that would work with both of those yeasts I’m all ears!

 

[carl_saint]

As a rule of thumb, I would never use more than 20% to top up post boil. 50% is way too much!

 

[Monkhouse]

As a rule of thumb, I would never use more than 20% to top up post boil. 50% is way too much!

Why’s that?

 

[carl_saint]

To be able to HG brew to 50% you'll need a big grain bill and hardly any sparge water so your efficiency will drop off a cliff. Also, due to the high concentration, there is reduced utilisation of hops during the wort kettle boil. A further disadvantage of HG brewing is that following dilution the beer does not exhibit the same profile of volatile compounds as that found in beer produced using normal gravity worts.

 

[Twostage]

I’m sure I’ve read somewhere that 20% is un-noticeable but above that it becomes more and more noticeable. I’ll see if I can find where I’ve seen it.

 

[Twostage]

Quick google. Can’t find anything concrete apart from mentions of 10-30% is ok. You could try an asymmetrical split and dilute one FV than the other and see how it turns out.