How Important Is Mash Volume?

[MattC]

Hi all, I have just brewed my second all grain and am keen do start doing double batches very soon as I wish to obtain more beer for my time!! I currently use a converted 38L Coleman drink cooler as a mash tun and a 60L stock pot as a boiler. I have been fiddling around in Beersmith with figures in order to determine how best to do a double batch. The way I figure it is to have a final vol of 46L with a top up volume of 10L into the fermenter. this way it will ensure I dont have any boil overs as I probably would if I boiled the entire batch.

Beersmith calculates my mash volume as being 29.21 L and sparge volume as 25.84 L. This will give me a boil volume of 43.83 L, after boil loss and top up, I will have a final Vol of 46L.

My question is, with a mash tun capacity of 38L, will I be able to use 29+ L of mash water to mash 11+kg of grain? Becuase I dont think it will fit???

Is this mash volume a must and what will happen if i use less mash water?

What do others do?

 

[Gulf Brewery]

My question is, with a mash tun capacity of 38L, will I be able to use 29+ L of mash water to mash 11+kg of grain? Becuase I dont think it will fit???

Is this mash volume a must and what will happen if i use less mash water?

What do others do?

Hi MattC

Congratulations on making the move to AG. I use about a 38 litre keg (was an old one cut down) for my batches and while you can fit it in there, it is full. I reckon a bit over 9kg of grain is enough in that size to give you room.

You can cut down the amount of mash water. Usually people work on 2.5 to 3.0 litres per kg. (these are typical figures for homebrewers, google will show you why). A stiff mash (less than 2.5) is a real bugger to work with and you have to make sure that all of the grain is thoroughly mixed with the water.

Edit - Just had a look at one of my reference books (pro brewing) and that says 2.5 is typical. You could just try it and see how much you can get in


Cheers
Pedro

 

[Millet Man]

My question is, with a mash tun capacity of 38L, will I be able to use 29+ L of mash water to mash 11+kg of grain? Becuase I dont think it will fit???

The malt will take up about 2/3rds of its weight in volume in the mash, so 11 kg will equate to a mash volume of about 7.5 litres plus 29 litres of water will give you a total mash volume of 36.5 litres. It will be a bit tight for sure.

Cheers, Andrew.