Post Brew day extract addition??

[DHaught]

Last night I brewed an IPA but due to a miscalculation I missed my O.G. and ended up with a 1.052 and probably should have tried to be mid to high 1.060's.
It's a 5 gallon batch and has been fermenting since last night.
Can I boil up some concentrated wort and add it to the fermenter today to get my gravity up and if so how do I calculate how the addition will effect the gravity of the beer?

 

[scoundrel]

I had the same thing. I OG reading was 1.036. I boiled up 2lbs DME and added it. Gravity ended up at 1.062. It turned out fine. Almost like a late extract addition. I would ad maybe a pound of DME, take a reading and call it a day. There are formulas to calculate the OG based on extract addition if your really concerned with a specific number. I'd just add it and if it ends up at 1.070, no big deal.

 

[Calder]

There is no problem adding extract while it is fermenting. Some people do this deliberately for higher gravity beers, to reduce the osmotic pressure on the yeast.

1 lb of LME has 36 gravity points, so in 5 gallons, it will add 7 points per gallon.

1 lb of DME has 45 gravity points, so in 5 gallons, it will add 9 points per gallon.

Assuming you have 5 gallons at 1.052 (5 x 52 = 260 gravity points). If you add 2 lbs of LME in 0.5 gallons (2 x 36 = 72 gravity points), you will end up with 5.5 gallons of wort with and effective OG of 1.060. Total gravity points = 260 + 72 = 332. Divide 332 by 5.5 = 60, or 1.060.

 

[DHaught]

Thanks for the replies. I ended up adding about 3/4 lb of DME boiled in about 1/3 gallon of water. Should have the desired effect.