Question -- Calculating OG for 5 Gal, from a 3 Gal sample

[Fionnbharr]

I've been brewing for about six months, and am trying to get a better understanding of the science behind the art of homebrew.

Suppose I take a hydrometer reading of a 3 gallon partial boil, and I want to know what the reading will be after I add another two gallons of water.

If, for example, the 3 gallon reading is 1.080, is the calculation just the straightforward:

((3 Gallons) x (1.080) + (2 Gallons) x (1.000)) / (5 Gallons) = Overall OG

which becomes

(3.240 + 2.000) / 5 = Overall OG

And then

5.240 / 5 = Overall OG

and finally,

1.048 = Overall OG?


I just want to make sure I've got the basics down before I hurt myself doing anything more fancy with the numbers.

 

[Moonlighter]

Looks good to me, wonder

 

[Moonlighter]

Oops phone error. I was saying your method looks okay to me.

I like the points method. You have 80 points in 3 gallons or 240 points. 240/5=48 points. So the diluted worth has gravity 1.048. Same results different method. Cheers

 

[Fionnbharr]

Thanks for the quick reply and good feedback!

 

[organ]

edit: makes sense