Splitting & Diluting a Batch

[Wez]

I'd quite like to be able to produce more beer from one mash. The idea I have is to get a larger mash tun to produce a higher gravity wort, splt it between 2 FV's and dilute down, but i'm not sure if it's as simple as that and if there are any pitfalls?

My idea would be to end up with 50L (2x 25L fv's) of 1.045 40 IBU wort: So I would brew 25L of 1.090 80IBU wort then split it so I have 12.5L of this wort into 2 FV's and then dilute down to 1.045 and presumably 40IBU.

Would this work? And by adding 12.5L water to 12.5L 1.090 wort does it dilute down by 50% i.e. will it end up at half the SG by doubling the volume or is there another calculation for working out how much water to add?

If it sounds lke this will work i'll get a larger MT as the current one only allows a max of 1.060

[mysterio]

Shouldn't be a problem with that... just remember you'll get significantly decreased hop utilisation when boiling such a concentrated wort, you'll get somewhere in the region of a third less bittering (in theory).

[Wez]

Cheers Mysty

I recon i'll need a coolbox that'll hold 10kg grain, can anyone recommend one that they use for this qty grain?

[mysterio]

Not tempted to go for one of the shiny thermo boxes on ebay? £43 for one of the 50Ltr ones. To be honest i've not seen a comparable sized plastic cool box go for much cheaper.

[Wez]

I could be, not being the best DIY'er i'd probably need 4 of them, 3 of them would be drilling target practice

[confused]

I've often wondered if this was possible, but to provide two half mashes with slightly different gravity - instead of splitting into two 1045s, get a 1050 and a 1040, then see what the difference in the finished beer is.

[Wez]

I think that it's called parti-gyle(sp?) iirc SteveD is the resident expert on this.

I just want to make more beer for my time, eventually I want to upgrade to a bigger system rather than splitting but this seems like a good / cheap way to do it.

I have a concern about the amount of hops I'd have in the 33l (25L) boiler ~ 180g

[agentgonzo]

As Wez mentioned, this is Partigyling. As a rule of thumb, if you split the batch 50:50 when sparging, the first half will be twice the SG of the second.
If you split the batch 33:67 when sparging, the SG of the first half will be twice the SG of the second again.

Diluting with an equal amount of water will indeed halve the SG.

Instead of collecting the wort and then diluting it with fresh liquor, you'd get a better efficiency to use that liquor to sparge the grains and get more of the sugars out of the mash. If you're collecting wort at ~1.090SG then there'll be quite a bit of sugar left in the mash tun.

[Wez]

Cheers guy's some really useful info there

I'm going to try to do this with my next brew, DaaB iirc you use the same boiler as me (leyland 33l bucket 2 elements and a leyland hop strainer?) do you think i'll have a problem with the amount of hops i'm going to have to use to hit the IBU's I'll need? ie will i loose loads (too much)wort to the hops? i think i'll have to use ~200 to 250g

[SiHoltye]

That high gravity brewing sounds quite distressing if it's commercially widespread. Can anyone shame any breweries who might dilute a higher gravity wort, adding sugars to hit targets and using hop extracts. Does this tie in with brews people see as less 'good', or that may have decreased as these technique becomes adopted?

[Wez]

you can always produce 20L of a super strength wort and let it down to 40L of moderate strength wort split between 2 fermenters.

Thats my intention, I am hoping it'll mean I can put off buying a bigger boiler for a bit, i'd love to get 40L out of a 6hr brewday rather than the 25L i get at the moment.

I think I'll be getting a bigger MT soon.

[SiHoltye]

The dilution thing sounds OK, it's just the additions that sound a bit 'quick fix'. The hop liquid in particular, sounds a bit clinical.

[MARMITE]

I built my own mash tun about 20 yrs ago and it's still going strong after 65 mashes.
It's based on a standard 5 gallon fermentation bucket, sitting inside a normal plastic dustbin. It holds 7 kg of grain, is deep rather than wide with a perforated false bottom. Heat loss is less than 2degrees over 90mins and mash tun run off is superb. Mash eff can be as high as 95%. You don't have to be brilliant at DIY to build it - so I could knock up some plans if you are interested.

I have just built another mash tun using a wooden hogshead as the outside skin. I cannot recall the capacity of the inner container but it must be able to contain 20kg of grain at least. Again it is deep rather than wide - ideal for good mash eff.
The only limitation with a similar set up is to obtain an inner container of food grade quality of the size you require and another container of larger dimensions for the outer skin.

[Martin the fish]

I've just done a 38 ltr batch with my 25ltr system. It was a bit more fiddling about and clearing up but well worth it. I ended up(unintentionally) with 20 ltr 1044 & 18ltr 1049.
Ideally i would have put them both in a single FV and fermented the whole batch as one but my big FV was in use. So i split the two. Tried a different yeast on each too.

I think next time i'll aim to get 15ltr high SG wort and 20 of lower. Sounds a great idea to me.
I managed 9kg of grain in my 33ltr coolbox mash tun and 20 ltr's strike water.

[Gurgeh]

you'll see a loss in efficiency too i think...?

you'll need more than double the grain bill to get double the gravity...