Dilution Question

[J_P]

Morning All

I was wondering if anyone could tell me the sum for working out the gravity of wort when you've diluted it.

For example I overshot my target gravity last night* quite significantly but undershot my target volume so instead of ending up with 23l of 1045 wort I got 22l of 1054 I am planning on adding a couple of litres of boiled cooled water to the fermenter this evening and would like to know how I work out what the gravity of the wort would have been if I'd have done it yesterday. Does that make sense?

Cheers in advance

*Yes I was brewing, really sorry about the lack of a thread or any pictures, the inside of my kitchen isn't very exciting. I promise to make up for it this summer with lots of outdoor pictures

[J_P]

Magic

Cheers Daab - bang on the money again!

[Graham]

If you are definitely going to add 2 litres then.

(22 x 54)/24 = 47.5 ~= 1048

If you want the amount of water to add to give 1045

(22x54)/45 = 26.4 litres total, so add 4.4 litres

[edit] Oh bugger, daab's beat me to it[/edit]
[edit]Oh bugger again, I can't subtract - corrected[/edit]

[Andy]

If you are definitely going to add 2 litres then.

(22 x 54)/24 = 47.5 ~= 1048

If you want the amount of water to add to give 1045

(22x54)/45 = 26.4 litres total, so add 3.4 litres

You mean 4.4 litres Graham ?

I knocked up a calculator to do the sums (bottom one on page)

http://www.jimsbeerkit.co.uk/calc.html

[Graham]

If you are definitely going to add 2 litres then.

(22 x 54)/24 = 47.5 ~= 1048

If you want the amount of water to add to give 1045

(22x54)/45 = 26.4 litres total, so add 3.4 litres

You mean 4.4 litres Graham ?

I knocked up a calculator to do the sums (bottom one on page)

http://www.jimsbeerkit.co.uk/calc.html

Thanks - I've corrected it.

[J_P]

4.4 litres is what I have scribbled on the bit of paper infront of me.

Again, cheers for your input I'll dilute the wort tonight.

[Danny]

Whilst we're on the subject this is what I've done and i would appreciate comment ...

By the time i've sparged and boiled i'm finding that i'm short several litres at around 1075 ... i'm diluting down to 1040 with tap water before pitching ... normally get back to about 22litres ...

the beer is coming out great but i wonder if maybe the water needs boiling first to avoid nastyness ...