Low OG

[Doogie312]

My buddy and I brewed a peanut butter cup stout kit today from Northern Brewer. I was concerned about not having enough preboil volume so we used all of the 4.5 gallons of sparge water and ended up with 7.75 gal into the kettle. After the boil we were left with 6.5 gal. The OG for the recipe is 1.085 but we ended up at 1.055. Will this just give a lower abv? Are there other effects with a lower OG?

 

[davidabcd]

lower ABV as you pointed out and a thinner beer, watered down. I looked up the kit instruction and it's supposed to be five gallons which would explain your gravity reading.

 

[Doogie312]

Thank you for the response. Lesson learned about the boil volume. This kit was supposed to be 9% abv. I used two packs of US-05 yeast. Any guesstimate on where it will end up?

 

[bracconiere]

i was calculating the ABV in beerwmith but it was making my brain hurt....i hear there's free online thingie's that can calculate OG/FG aBV....i've heard of brewer's friend?

edit: i did make it far enough to figure you'd get a little under 6% at an estimated FG of 1.012....

 

[frankvw]

Thank you for the response. Lesson learned about the boil volume. This kit was supposed to be 9% abv. I used two packs of US-05 yeast. Any guesstimate on where it will end up?

As a rule of thumb, your ABV decrease is the inverse of your volume increase. So 5.5 gal. at 9% = 6.5 gal at (5/6.5 x 9) = 6.9%. Alcohol production is not a factor of yeast, i.e. more yeast does not mean more alcohol. Two packets of US-05 is a bit more than you need for this OG so you'll have a "cleaner" palate with less fruity esters, but other than that you'll be fine.