
01212010, 10:18 PM

#1

Feedback Score: 2 reviews
Join Date: Apr 2008
Location: Denver.
Posts: 2,618
Liked 19 Times on 19 Posts Likes Given: 17

Adding DME to boost efficiency


What is the formula for adding DME to the boil to boost efficiency if need be? I can't seem to find any info. Perhaps I am searching the wrong phrase. If there is a thread on the please post the link.



01212010, 10:24 PM

#2

Feedback Score: 6 reviews
Join Date: Jan 2009
Location: San Francisco, CA
Posts: 1,439
Liked 72 Times on 64 Posts Likes Given: 25

i don't have it, but if you are misspelling the terms (as in your title) that might be the issue



01212010, 10:31 PM

#3

Feedback Score: 2 reviews
Join Date: Apr 2008
Location: Denver.
Posts: 2,618
Liked 19 Times on 19 Posts Likes Given: 17

Quote:
Originally Posted by midfielder5
i don't have it, but if you are misspelling the terms (as in your title) that might be the issue

just saw that. I do not see how I can edit the title of my posting



01222010, 12:30 AM

#4

Senior Member
Feedback Score: 0 reviews
Join Date: Oct 2005
Location: Long Island
Posts: 4,646
Liked 104 Times on 98 Posts Likes Given: 39

Adding DME to your boil will not improve efficiency. It will increase your OG, which could be good if your OG is low. To do this successfully, you need to know your preboil volume, postboil volume, preboil gravity, and required postboil gravity.
Here's the math.
Assume your preboil volume is V1, your post boil volume is V2, and your preboil gravity is G1.
Your post boil gravity (G2) will be 1 + ((G1  1.0) * V1 / V2)
i.e. if you start with G1 = 1.040, V1 = 7 gal, and V2 = 5.5 gal, your post boil gravity (G2) will be:
1 + ((1.040  1.0) * 7 / 5.5)
or 1 + ((0.040) * 7 / 5.5)
or 1 + .051
or 1.051
If you want your OG to be 1.062, subtract G2 from that, and that gives you the gravity points shortage. i.e. 1.062  0.051 = a shortage of 0.011
Now you need to calculate how much DME you need to add to make up that gravity points shortage.
Assume GS is the gravity points shortage (0.011), and V2 is the estimated post boil volume (5.5 gal)
The amount of DME you need to add is GS * V2 / 0.046 i.e. 0.011 * 5.5 / 0.046 or 1.32 lb DME.
Hope this makes sense,
a.
__________________
There are only 10 types of people in this world. Those that understand binary, and those that don't.



01222010, 06:24 PM

#5

Feedback Score: 2 reviews
Join Date: Apr 2008
Location: Denver.
Posts: 2,618
Liked 19 Times on 19 Posts Likes Given: 17

Quote:
Originally Posted by ajf
Adding DME to your boil will not improve efficiency. It will increase your OG, which could be good if your OG is low. To do this successfully, you need to know your preboil volume, postboil volume, preboil gravity, and required postboil gravity.
Here's the math.
Assume your preboil volume is V1, your post boil volume is V2, and your preboil gravity is G1.
Your post boil gravity (G2) will be 1 + ((G1  1.0) * V1 / V2)
i.e. if you start with G1 = 1.040, V1 = 7 gal, and V2 = 5.5 gal, your post boil gravity (G2) will be:
1 + ((1.040  1.0) * 7 / 5.5)
or 1 + ((0.040) * 7 / 5.5)
or 1 + .051
or 1.051
If you want your OG to be 1.062, subtract G2 from that, and that gives you the gravity points shortage. i.e. 1.062  0.051 = a shortage of 0.011
Now you need to calculate how much DME you need to add to make up that gravity points shortage.
Assume GS is the gravity points shortage (0.011), and V2 is the estimated post boil volume (5.5 gal)
The amount of DME you need to add is GS * V2 / 0.046 i.e. 0.011 * 5.5 . 0.046 or 1.32 lb DME.
Hope this makes sense,
a.

Yes it does. Thanks



01232010, 01:22 AM

#6

Feedback Score: 0 reviews
Join Date: Dec 2009
Location: N. Idaho/NW Washington
Posts: 103

Why not just add more grains to your mash to increase OG? It will save you money.



01232010, 02:22 AM

#7

Feedback Score: 0 reviews
Join Date: Oct 2009
Location: Iowa
Posts: 14

Quote:
Originally Posted by TastySalmon
Why not just add more grains to your mash to increase OG? It will save you money.

I think his point is he has already mashed out and has low gravity and is trying to correct on the fly. Your approach would work for his next attempt at the same recipe if there were no other process influences though.



01242010, 07:02 PM

#8

Feedback Score: 2 reviews
Join Date: Apr 2008
Location: Denver.
Posts: 2,618
Liked 19 Times on 19 Posts Likes Given: 17

Quote:
Originally Posted by sweatje
I think his point is he has already mashed out and has low gravity and is trying to correct on the fly. Your approach would work for his next attempt at the same recipe if there were no other process influences though.

That is exactly why. I am generally either spot on or a few points +/ my perboil OG. However, I wanted to know what to do if I am not spot on





