DME and Specific Gravity

Is there any exact science to how much DME extract to add for reaching a desired gravity reading?

For example, if I wanted to make 3 gallons of beer with an original gravity of 1.044 how much DME would I have to add?

After doing some research the formula I've adapted for this is:

( x lbs DME x 45 points) / 3 gallons = 44

solve for x...

x = 44 x (3/45)
x = approx. 2.93 lbs.

I know that gravity has to do with multiplying weight x PPG of the extract, but do all DME's have a PPG of 45 and is the above formula going to work for all situations?



Thanks in advance!

I do know that Briess DME contributes 43 pts. per pound per gallon.

And your equation is right.

Cool. I want to make a braggot, now just have to figure out how much PPG there is in honey. But I'll probably just wing it.

glas9396 said:

Cool. I want to make a braggot, now just have to figure out how much PPG there is in honey. But I'll probably just wing it.

Click to expand...

I think honey varies a bit. ProMash lists it at 1.042 per pound per gallon and Beer Smith has it at 1.035.

Usually with meads, I'll add a little more honey that I think I'll need, then dilute down to the gravity I want. This is because of the issue noted above that honey varies GREATLY even season to season, brand to brand, location to location.

For something more complex like a Braggot, a better idea is to "proof" that batch of honey by making a very small sample to test with a hydrometer. Like gradually adding honey to 10oz of water, an ounce at a time. Then note the amount when you hit your spot. This way your not diluting your malt as with the method above.

For a braggot, I might expect to proof around 1oz honey to 8oz water (while like 3-5oz for heavier meads).

Hey HP that's a good idea. I'm now looking for an objective way to determine PPG of a fermentable. I suppose if one measured the specific gravity of a certain quantity of honey in a certain quantity of water they could then figure the PPG of the fermentable. But then would this figure remain constant? Math is not my fourté sorry if this is painfully obvious to some.