how much DME do i add?

[McMalty]

K, long story short, some of my wort boiled over and therefore left me with less fermentables.

right now, my SG is 1080 with 4.5 gallons in my carboy. How much DME & water do I need to add to maintain an SG of 1.080 for 5 gallons?

Thanks

 

[Calder]

1 lb of DME has 45 gravity points. That is, it will give you a gravity of 1.045 when dissolved in 1 gallon of water.

1 lb of DME in half a gallon will give you 1.090, so to get 1.080 you need roughly 10% less, or 0.9 lbs (14 ozs).

 

[jmprdood]

Public math - nice job Calder

 

[Rbeckett]

For that small of a difference I would just throw a one ponder in, stir the crap out of it and pitch yeast. The small difference is not going to make much if any difference in your final ABV. What style or flavor are you going for? Some clones are a little more particular if your looking for an exact replica, but for most of our purposes close enough is good enough. Just my .02
Bob

 

[McMalty]

For that small of a difference I would just throw a one ponder in, stir the crap out of it and pitch yeast. The small difference is not going to make much if any difference in your final ABV. What style or flavor are you going for? Some clones are a little more particular if your looking for an exact replica, but for most of our purposes close enough is good enough. Just my .02
Bob

Double IPAish kind of brew. It's not a clone, it's my own recipe. I'm not sure it's really that "small a difference" though. 1/2 gal of pure water will bring my SG down to 1070, thats a huge difference to me. So what i ended up doing was what Calder suggested.... dissolved 15 oz of DME in 1/2 gal of water and added it to the carboy. My SG came out perfectly to 1080, so much appreciated Calder. Altho, i'm concerned a bit about the hoppiness, since the DME was not boiled with the hops, and additionally, i lost some hops to my boil-over....just how much is the question; it's kinda difficult to tell with dissolved pellets.

It's in the basement just starting to ferment. Thanks all for ur help

 

[DeafSmith]

Another method to calculate it (very old school):

*Using a slide rule, place the cursor hairline on 8 (the gravity) on the D scale
*Bring 4.5 (the volume) on the CI scale under the hairline - read the number on the D scale under the left index of the C scale = 3.6 or 360 gravity points.
*Bring 5.0 (the desired volume) on the CI scale under the hairline - read the number on the D scale under the left index of the C scale = 4.0 or 400 gravity points needed.
* 400 - 360 = 40 points needed to add, or about 0.9 lbs.

 

[FatBaldBeerGuy]

Another method to calculate it (very old school):

*Using a slide rule, place the cursor hairline on 8 (the gravity) on the D scale
*Bring 4.5 (the volume) on the CI scale under the hairline - read the number on the D scale under the left index of the C scale = 3.6 or 360 gravity points.
*Bring 5.0 (the desired volume) on the CI scale under the hairline - read the number on the D scale under the left index of the C scale = 4.0 or 400 gravity points needed.
* 400 - 360 = 40 points needed to add, or about 0.9 lbs.

Hehe I tried that out with my Digital sliderule and works perfectly

 

[DeafSmith]

Hehe I tried that out with my Digital sliderule and works perfectly

I find a slide rule easier to use for some things than a calculator; for example, when I measure my preboil gravity and volume and want to know what volume to boil down to for a specified OG, I just put the hairline on the volume on the D scale, slide the preboil gravity (actually 1 - gravity) on the CI scale under the hairline, then I can see at a glance what the OG will be for any postboil volume. For example, if my preboil is 6.75 gallons at 1.044 and I want to hit an OG of 1.052, I just set the hairline on 6.75 on D, move the slide to pull 4.4 on CI under the hairline, and then set the hairline on 5.2 on the CI scale and read about 5.71 on D or 5.7 gallons. And by simply sliding the hairline to any gravity on CI I can find the postboil volume to get that gravity, or conversely, by sliding the hairline to any volume number on D, I can read the corresponding gravity on CI.