Figuring out gravity when adding juice

[sprucecampbell]

I have some blueberry juice that is 67 brix (1.3356 SG). I want to make a 20 gallon batch total. I am trying to figure out what my gravity will be if I add one pound/gallon (which is easier to calculate?) to 5 gallons of water. is there a formula for this? I found one but it was after the beer was made (http://www.themadfermentationist.com/2010/10/adding-fruit-to-beer-increases-alcohol.html). Can I use this even though I am just starting at 1? I am making Kombucha so the only ingredients are juice and sugar. I need to figure out what the sugar in the juice dilutes out to so I can finalize how much sugar to add. Thank you for your help.

 

[beergolf]

When I have added juice to a brew I just looked at the nutrition label. It lists the amoung of sugar per serving.. Calculate how much jusice you are adding and this will give you amount of sugar. Then just plug in the amount of sugar into your brew software.

 

[feinbera]

Just multiply the points times the gallons to get total points, then divide by the total volume to get a weighted average.

• 1 x 1.3356 = 3356 points from the juice
• 5 x 1.000 = 0 points from the water (this step is kinda dumb in this particular case, but you can see how it would work out if you were blending two liquids of different, non-zero gravities...)
• 3356 + 0 = 3356 total points; 1 + 5 = 6 total gallons
• 3356 points / 6 gallons = about 559 points = 1.0559 gravity

 

[broadbill]

Just multiply the points times the gallons to get total points, then divide by the total volume to get a weighted average.

• 1 x 1.3356 = 3356 points from the juice
• 5 x 1.000 = 0 points from the water (this step is kinda dumb in this particular case, but you can see how it would work out if you were blending two liquids of different, non-zero gravities...)
• 3356 + 0 = 3356 total points; 1 + 5 = 6 total gallons
• 3356 points / 6 gallons = about 559 points = 1.0559 gravity

You muffed the first equation, but you also muffed the last equation, giving the right answer

1.3356 equals 335 points per gallon, not 3356.
Likewise, 559 points per gallon equals an OG of 1.559 not 1.0559.

see the "brewer's points" section here

You start with 1 gallon of blueberry juice at 1.3356. According to the points calculation (see wiki) the juice is you have 335.6 points per gallon (P = (OG-1)*1000). You are going to take 1 gallon of juice and dilute with 5 gallons of water, for 6 gallons total.

Easiest way to calculate this is using the dilution equation:
c1v1 =c2v2

335.6 points x 1 gallon = (x) x 6 gallons
335.6 = 6x
x=55.6=56

convert points/gallon back to OG: 1.056

 

[sprucecampbell]

Can I hug all of you? You are the best. If you ever find yourself if Columbus, Ohio or Seoul, Korea. Your beers on me.

 

[adamdillabo]

Ohio or Korea? That's a big difference. Are you in both places at once?

 

[sprucecampbell]

I currently live in Columbus, Ohio. I will be opening a brewery here in a few years. However, I am opening a brewery in Seoul next year. So I will be in Seoul next year for 6 months setting it up. I am helping a Kombutcha maker produce higher gravity Kombutcha. But I wasn't familiar with adding straight concentrate. Thanks for the help, I hit the exact gravity I wanted.