# How much volume does a pound of dme take up?

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#### rocketman768

##### Supporting Member
HBT Supporter
I need an answer quick. I got 6 lbs of dme and need to know how much it will increase the volume when I add it. Don't want to overflow my kettle.

#### Yuri_Rage

##### Gritty.
HBT Supporter
Not much. It's mostly sugar, which dissolves readily and doesn't appreciably increase the overall volume. Still, leave yourself adequate room for boilover prevention.

OP
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#### rocketman768

##### Supporting Member
HBT Supporter
No, I'm talking like 6 lbs. I need a number. I read while googling that it's about 1/3 lb per cup. If so, that means 6 lbs is 1.125 gallons. I estimated 1 gallon, so I think I'm gonna be ok. Can anyone confirm this density? Of course, this is over the real density since I think they're just talking about measuring dme with cups.

#### motobrewer

##### I'm no atheist scientist, but...
definitely not 1.125 gallons...

as yuri said, it's sugar, which dissolves into a solution...

if you left enough for your estimate of 1 gallon, you'll be fine...

good luck...

#### motobrewer

##### I'm no atheist scientist, but...
that sounds better

you could always experiment. 5 gallons = 18.9 liters.

take 1 liter of water, and then add (6/18.9) lb of dme (about 1/3rd). see how much volume you have then. rescale to 5 gallons.

also note, and i preface this with it's been awhile since chem, but it might be temperature dependent.

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#### rocketman768

##### Supporting Member
HBT Supporter
that sounds better

you could always experiment. 5 gallons = 18.9 liters.

take 1 liter of water, and then add (6/18.9) lb of dme (about 1/3rd). see how much volume you have then. rescale to 5 gallons.

also note, and i preface this with it's been awhile since chem, but it might be temperature dependent.

Good idea. However, I'll do it on a mL scale so I don't waste so much dme.

#### ajf

##### Senior Member
HBT Supporter
1 lb DME dissolved in 1 gal water yields a gravity of 1.046.
If you start with 1 gal water (which weighs 8.35 lbs) and add 1 lb DME. You end up with x gallons of wort with a gravity of 1.046 weighing 9.35 lbs.
Divide 9.35 by 1.046 to give you the weight of the equivalent volume of water = 8.94 lbs, so you have a volume of 8.94 / 8.35 gallons = 1.07 gallons.

Therefore 1 lb DME (when dissolved in water increases the voulme by 0.07 gallons.

-a.

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#### rocketman768

##### Supporting Member
HBT Supporter
1 lb DME dissolved in 1 gal water yields a gravity of 1.046.
If you start with 1 gal water (which weighs 8.35 lbs) and add 1 lb DME. You end up with x gallons of wort with a gravity of 1.046 weighing 9.35 lbs.
Divide 9.35 by 1.046 to give you the weight of the equivalent volume of water = 8.94 lbs, so you have a volume of 8.94 / 8.35 gallons = 1.07 gallons.

Therefore 1 lb DME (when dissolved in water increases the voulme by 0.07 gallons.

-a.

Although this is a good approximation you can't exactly do it this way, because pppg is given by gallons of solution, not gallons of initial water. Adding DME to 1 gallon of water would get you something more than 1 gallon, which would cause your SG to go down. To get 1 gallon of solution with 1 lb of DME, you have to add water to the DME to bring the volume to 1 gallon, so without knowing how much volume the DME will occupy, you don't know how much water is in the 1 gallon of solution.

Experiment done. Put 25 mL water in a graduated conical tube. Added 20.0g of DME. Final volume was 36 mL, so the density is about 20g/11mL = 1.8 g/mL. This means that my 6 lbs of DME took up 0.4 gal. Good thing the density was close to that of glucose, cuz I nailed my target volume.

#### ajf

##### Senior Member
HBT Supporter
You're right. Shows what a couple pints of ESB does to my brain.

Take 1 lb DME and add x lb water to top off to 1 gallon. You now have 1 gallon with a gravity of 1.046. The weight of this solution is 8.345404 lbs * 1.046 = 8.729292584 lbs.
As 1 lb of this weight was the DME, x = 7.729292584 lbs, so you started with 7.729292584/8.345404 gal water = 0.926 gal.
So 1 lb DME adds 0.074 gals in volume.

-a.

#### IceFisherChris

##### Well-Known Member
Nice calculation!

#### Jzak09

##### Well-Known Member
what about grain.. How much water does a pound of grain displace?

#### Vinic

##### Well-Known Member
13.38 lbs will increase volume by one gallon.

(sorry; not so quick. but for future reference, it's pretty accurate, if not useless for your purposes)

ELA

#### ajf

##### Senior Member
HBT Supporter
what about grain.. How much water does a pound of grain displace?
According to Promash, 1 lb grain displaces 0.32 qt.

-a.

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