Howto calculate mash water Volume (BIAB)

[Queequeg]

O.K so I am starting to mistrust beersmiths numbers.

Typically the ratio of water to grain for mashing is 1.3 Litre to 500g. But of course an calculations need to take into account the tun volume and dimensions to ensure that the grains are sufficently covered/immersed and that the tun dosn't over flow.

When I punch in my kit into Beersmith is always seems to generate some massive volume, I simply want to double check as space in my kettle is at premium and as a Partial mash BIAB brewer I want to get as many grains in my kettle as I can to get the best diastatic power and minimal DME I can.

My kettle is (approximately) 19L, dimension being 300mm in diameter, 260mm in height.

Is there a way I can manually calculate the maximum weight of grain I can fit in my kettle with mash water at a typical ratio like the above which accounts for water displacement?

Or is there a website were I can enter my kettle dimensions and it does all the work for me.

 

[Math0]

You can use the ratio you want! Usually, most people use a ratio of 1L-2L per pound of grain to mash. You don't have to do a full boil, meaning to add the whole batch size in the boil. You can add a ratio of 2L per pound of grain to mash and do the boil afterward. Don't forget to sparge if you need too. After the boil you can top up with the water you need to cool it even faster.

 

[Just-a-sip]

have you calculated your boil off rate and added this to your profiles on beer smith. for biab this is essential to get accurate numbers. also you need to take into account the boil off and the absorption. it may seem like large numbers but i can say that beersmith is amazingly accurate. for example after reading this i punched in a recipe for BIAB and it said i needed 9 gal to do a 5 gal batch. this took into account the grain and absorption and the boil off rate i programed for a vary accurate number,

 

[Queequeg]

I don't do a full boil, I make up to 6 Gallon in the fermenter. I happy to stick with the 2.6L to 1Kg ratio, I suppose the question is how much water does a 1 Kg of grain displace?

As for sparging I not sure I am convinced of its value in pm. Sparging is to increase effeciency which reduces the amount of grain need, but it increases the water volume, hence compromising the possible size of the grain bill in PM. This is not cost effective as you will need to use more extract which is much more expensive then even your'll lowest efficency mashing.

 

[Queequeg]

have you calculated your boil off rate and added this to your profiles on beer smith. for biab this is essential to get accurate numbers. also you need to take into account the boil off and the absorption. it may seem like large numbers but i can say that beersmith is amazingly accurate. for example after reading this i punched in a recipe for BIAB and it said i needed 9 gal to do a 5 gal batch. this took into account the grain and absorption and the boil off rate i programed for a vary accurate number,

I don't do full boils, so the boil off is pretty meaningless to me as I top up like an extract brewer. I select the PM profile in the options and have my own equipment profile, so it should account for this surely.

Diggin around in beersmith is would seem that is assumes 1kg of grain occupies 0.6520L of water. Yet is seems to assume a ratio of 7.35L of water per Kg of grain. This seems nuts to me.

Yep Beersmith is changing the water to grain ratio for no apparent reason, blizzarly I can't set it to how I want, just siwtches back.

 

[Queequeg]

Fixed now, it had full boil switch on in my mashing profile. School boy error.

 

[Just-a-sip]

that makes sense. know something was off beersmith is usually spot on.