How much volume does a pound of dme take up?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

Joined
Jul 24, 2006
Messages
14,260
Reaction score
780
Location
Southwest
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
OP
rocketman768

rocketman768

Supporting Member
HBT Supporter
Joined
Feb 5, 2008
Messages
1,083
Reaction score
28
Location
Evanston, IL
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...
Joined
Oct 12, 2009
Messages
8,323
Reaction score
504
Location
Thiensville
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...
Joined
Oct 12, 2009
Messages
8,323
Reaction score
504
Location
Thiensville
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.
 
OP
OP
rocketman768

rocketman768

Supporting Member
HBT Supporter
Joined
Feb 5, 2008
Messages
1,083
Reaction score
28
Location
Evanston, IL
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
Joined
Oct 29, 2005
Messages
4,648
Reaction score
121
Location
Long Island
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.
 
OP
OP
rocketman768

rocketman768

Supporting Member
HBT Supporter
Joined
Feb 5, 2008
Messages
1,083
Reaction score
28
Location
Evanston, IL
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
Joined
Oct 29, 2005
Messages
4,648
Reaction score
121
Location
Long Island
You're right. Shows what a couple pints of ESB does to my brain. :drunk:

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.
 

Vinic

Well-Known Member
Joined
Nov 9, 2009
Messages
81
Reaction score
6
Location
Missouri
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)
 
Top