Question about estimating OG

[VApatriot]

Hi all,

On Christmas day, I brewed a Belgian Dubbel extract kit from NB. My final volume was 4 1/2 gallons and my O.G. was 1.068 taken from the brew kettle. I added 1/2 gallon of filtered water right before pitching my yeast to get the final volume up to 5 gallons. Here's my question: after adding the 1/2 gallon of water, how can I estimate my O.G. resulting from the small dilution?

I pitched the WLP575 I washed from the Belgian Tripel I made in the beginning of December and after 2 weeks the gravity reading is 1.010, so, so far so good.

Thanks for any and all responses, and Happy New Year to everyone!

 

[RiverCityBrewer]

After diluting 4.5 gallons of 1.068 wort to 5 gallons, that would put you at an OG of about 1.061, so if you are at 1.010 right now, you are sitting at about 6.7% ABV. I used BeerSmith to perform the calculations, but I'm sure other programs or spreadsheets available that can do them as well.

 

[RiverCityBrewer]

Also forgot to add the simple math to perform the dilution:

Take the volume you have and divide it by your intended final volume, so 4.5/5 = .9

.9 is your dilution factor so take this and multiply that by your measured OG (only the whole numbers after the decimal), so .9 * 68 = 61.2

String it back together and you have 1.061.... someone may have a more complicated formula that will take into account various factors, but this is just a simple ratio equation that is accurate enough for me.

Hope that helps.

 

[dcp27]

There isn't any more complicated of a formula to figure out the new OG. OG is just a sum of the gravity points from your malt divided by the volume.