Would this work?

[delzep]

I'm currently brewing using the partial mash and partial boil method by mashing about 2kg of grain in a 15 litre pot with about 4.5-5 litres of water. I then wash the grain with about the same amount and away I go.

Would I be able to increase the amount of grain I use (i.e. double the amount) and split the grain into two mashes and mix the two volumes of wort together and boil?

Like this

Mash 1: 4.5 litres of water with 2kg of grain. Wash with 4.5 litres of water

Mash 2: 4.5 litres of water with 2kg of grain. Wash with the same 4.5 litres of water from mash 1 (or would fresh water be more suited?)

I reckon that would leave me with about 11.5ish litres of wort that I could brew in my 15 litre pot

Thoughts?

[Ciderhead]

it would be more efficient to wash with fresh water on Mash 2
In essence all you are doing is doubling your batch right?

[delzep]

Doubling the amount of grain (and therefore reducing the amount of DME)...same size batch.

I can store the initial wort in a bucket while I mash the second lot of grain.

[Ciderhead]

grain is always better that DME

[delzep]

grain is always better that DME

Yep


cheaper too 

[delzep]

So if I had a grain bill such as this (for example)
2.5kg maris otter
1kg roasted barley
0.5kg chocolate malt

Could I split the grain into two batches of

1.25kg maris otter
0.5kg roasted barley
0.25kg chocolate malt

and then perform two mashes and then simply add the two worts together. Would colour be affected by this (which would be more important in lighter coloured beers I suppose)

[DEMPSEY]

Your recipe has 25% roast barley and a further 12.5% chocolate malt,that seems alot of adjuncts for the base malt to deal with. I would also guess that this would produce a harsh tasting beer. :-/

[delzep]

That was just a made up recipe from the top of me head. I'd be adding DME as its partial mash. Was more about the method than the ingredients

[johnrm]

Splitting your grain into two batches is doubling the effort for that part  of your brew.
Once your ratios remain identical then the color should not be affected.

[delzep]

Finally got around to doing this on Friday. Was a bit slower than expected, but the experiment worked. Would have used 1.7kg of dme but cos I used an extra 2kg of base malt (thanks CARA!) I ended up using just 500g of dme. So instead of partial mash I'm gonna call it mostly mashed 

[Padraic]

"Mostly mashed" I like it!

I'd go with mashed, and list your dme as an adjunct!