All Grain Partial Boil Efficiency

[benkbenkbenk]

I am getting into all-grain brewing after cutting my teeth on extract and then partial mashing. I have been given a 30 litre cool box type mash tun but I can only boil up about 15 litres due to the size of my kitchen and my pan. I haven't found a suitable guide for this process, and I am struggling with how best to mash/sparge it to get best efficiency.

I brewed this weekend using the following grain bill:

Torrified Wheat 0.5Kg
Crystal 100L 0.135Kg
Maris Otter 4Kg

• Used 12.1 litres of strike water at 73C. (I put water at 85C in the cooler and let the temp fall to 73C before adding the grain)[/*:m:mxuegy9v]
• Added the grain (in a large grain bag for easier removal) and stirred.[/*:m:mxuegy9v]
• Measured the temp and it was at my target temp of 66C and left it for 90mins.[/*:m:mxuegy9v]
• Measured the temp again and it had fallen by less than 1C over the 90 mins.[/*:m:mxuegy9v]
• Drained the wort into my kettle I had around 6 litres.[/*:m:mxuegy9v]
• Added 4 litres of water at 66C to the grain, stirred and let it sit for 10mins, drained the wort.[/*:m:mxuegy9v]
• Added another 4 litres of water at 85C as a kind of mash out, stirred and let it sit for a couple of minutes before draining again. [/*:m:mxuegy9v]

This process only gave me 60% efficiency. I think if I could sparge with more water that efficiency would be increased, but obviously I can't because I can only boil about 14-15litres.

Is there anything I can do to improve this efficiency? Or am I going to be stuck with partial mashing until I get a bigger house!

Thanks in advance!

 

[RobWalker]

could you sparge, or add more water and do BIAB in a mash tun sort of thing - and add this towards the end of the boil?

 

[benkbenkbenk]

I suppose I could do something like that, and just keep sparging and topping up throughout the boil. It would probably only be a couple of extra litres though right? I'm not sure how much boils off in an hour.

Also, this would make it pretty tricky to calculate my efficiency. Although I'm sure there must a be a calculation to add multiple gravity readings together.

Also, another quick question and a bit of an aside... my mash tun has a brass tap (outdoor garden hose type) and in this first brew I had no hose so my wort was run off out of the tap and straight into my kettle, does it matter much if the wort gets a bit aerated at this stage? I tried to run it down the side of the kettle to avoid this. I presume I wont be able to use a garden hose, and will require some food/water grade piping if aeration is an issue.