Grain volume question

[RichardG]

Does anyone know the approximate volume of 1kg of grain?

[Lime Corridor]

OK, so this is top of the head stuff, but I use a 2 litre plastic jug when weighing out my grain and when this is filled to the top it is 1kg of M.O.

Is this what you are looking for/helpful?

LC

[micromaniac]

+1 for the 2ltr jug full to the top holds about 1100/1200 grams

[vacant]

Wet or dry volume? i.e. are you trying to work out mash tun size requirements?

[Kev888]

It varies a bit but I find for storage purposes allowing a bit more than 2L per kg would be a good estimate.
If you are interested in how much liquid it displaces though, then (once soaked in) I reckon on about 0.65L/kg (or so), and its usually about right.

Cheers
Kev

[far9410]

I would think it varies slightly according to the amount measured, as a large quantity would compress more.

[RichardG]

It's dry weight I'm interested in. Basically, 2kg of dry grain is approx 1Ltr volume it seems.

[Lime Corridor]

Basically, 2kg of dry grain is approx 1Ltr volume it seems.

You have the wrong way around don't you? 2kg of dry grain would be 4(ish) litres of volume. 1kg=2 litres.

LC

[RichardG]

Sorry, yes, my mistake.

[RichardG]

My question arises from my proposed next brew. I'm looking at a Kholsch, and when I brought this to the forum recently, BW was recommending a decoction mash. As he strikes me as a man who knows his stuff, I decided to look into this. Firstly, I appreciate that there's much debate about whether this is really necessary these days, given the highly modified nature of even pilsner malt and such like. However, I firstly had to ascertain whether this was even possible with the kit I have available, and that meant finding out the volume of the mash I'd be drawing off. Even if I do this, I'm only going for a single decoction, and as I understand it I need to draw off c40% of the mash to boil. Now, I'm going for a 20Ltr brew, using 4kg of pilnser malt (my thanks to The Malt Miller) and 200g of wheat malt. I'll have some 10Ltrs of mash liquor and, according to the above, some 8Ltrs of grain. So, 40% there-of is some 7.5Ltrs (rounding up) which I'll need to boil. As it happens I do have a pan big enough to comfortably hold this, so I can proceed with this if I choose to.

[Andy]

The volume of dry grain will be different (greater) than the volume of wet grain in a mash. The usual suspect brewing software packages will give you a total mash volume if you provide liquor amount + grain weights.

[RichardG]

True enough, but my assumption was that the grain would absorb water, and that that absorbtion would be off-set by a reduction in water volume. So for example, 10 Ltrs of water added to 8 Ltrs of grain equals grain expanding to 12Ltrs (I'm making up numbers here, as I've no idea what the correct figure should be!), but 'free' water reducing by the same amount. Net result, the same total volumes - or am I way wrong?

[RichardG]

Actually, looking at Kev888's post above, he gives an absobtion figure of 0.65Ltrs/KG. Anyway, it probably isn't too critical as I'm just looking to see if this is feasible at the moment. My mash tun is a cool box with Ltr graduations in the side, so once I'm all mashed-in, I can see what the total volume is and work out how much I need to draw off subsequently. Having said that, it would be interesting to know how to work this out properly before hand.

[Andy]

Dry grain volume will include air space which will be displaced by water in a mash so it's not as simple as just water absorption into the grains.

[captain wassname]

you could do a mini mash in a 2litre jug 500 gms hot water and 500 gms PM and see where it comes to

Jim