Dilution to wort and how water effects OG

[mattpsu27]

Hi I'm new to the site although I've been brewing for quite some time. I have a quick question around dilution and the approximates on the gravity reading. I had a gravity reading of 1.078 after boil. Making an IPA. I diluted about 5 gal of wort with 32 oz of water but forgot to take another reading. Dumb I know.

Anyone know how much the OG would've dropped by/lowered to?

Thanks
Matt

 

[uncommonsense]

Quick check with my software say 1.074

 

[ktblunden]

640 oz (5 gal) times 1.078 equals 689.92
32 oz times 1.000 equals 32
689.92 plus 32 equals 721.92
721.92 divided by 672 oz equals 1.074

 

[mattpsu27]

640 oz (5 gal) times 1.078 equals 689.92
32 oz times 1.000 equals 32
689.92 plus 32 equals 721.92
721.92 divided by 672 oz equals 1.074

Thanks!

 

[nukebrewer]

An alternate approximation would be to take the original volume and divide it by the final volume to get a reduction factor. Then multiply the reduction factor by your initial points value ((SG-1)*1000). So,

RF = 5 gal/5.125 gal = .976

74 * .976 = 76

Convert back to SG is 1.076

I know it's different than what others have said, but just wanted to throw out a different way to do it that has always worked for me.

 

[mattpsu27]

Thanks. You misstated the 5.125 rather than 5.25 since 32 oz is .25 of 128, and 76 rather than 78 OG, but the actual calculation looks correct.

Appreciate everyone's help!

 

[nukebrewer]

Terribly sorry for that miscalculation. Using 5.25 gallons I also get 1.074.

 

[nukebrewer]

74 * .976 = 76

Haha, I think I was drunk when I wrote that. That just plain doesn't make any kind of sense. I meant 78 instead of 74.

 

[erockomania]

Or just type in 5.25 into our spread sheet