Correcting gravity after the fact...
OK, so I've got a beer in the fermenter right now that I brewed on the 4th... By tonight it'll be almost 48 hours into primary fermentation, and as of last night it was definitely rockin'.
Problem was, when I formulated my recipe, I used BrewSmith for the first time, and if anyone spotted my thread on that topic, let's just say I tweaked a couple parameters incorrectly and wound up with a lower OG than I had intended.
So now, a day and a half later, I'm considering how I might fix this, as BrewSmith can now reliably tell me I've actually just missed, to the low side, the style guidelines for an American IPA. I've got just about 6 gallons in my fermenter at the moment. What I want to do is to siphon off about a half gallon or so, add to that either a pound of extra light DME or table sugar, boil that for 10 or 15 minutes, chill it, and re-introduce it to the fermenter.
I know that a pound of table sugar will get me back up to my intended OG, and will also constitute a bit less than 10% of my fermentables, so I think I'd be relatively safe from cidery-like flavors - here's the current grain bill:
12oz crystal 40
12oz flaked barley
Or, I could go with a pound of DME, for a slightly lower gravity contribution but less of a risk of cidery notes.
By the time I do this, fermentation will have been rocking for a good 36 hours or so, so I really won't be concerned about conditioning yeast to go after simple sugars instead of maltose or anything like that, so that kind of concern can be disregarded too.
Which would you choose? I think I'm leaning towards the sugar, just to get to where I had intended to be gravity-wise... Though I guess I could always go with more than a pound of DME too...
EDIT: And now that I've done a little more of the math, I realize: A pound of sugar would actually slightly overshoot my target OG. So, I could add a little less than a pound (haven't done the exact math on that yet) or I could add 17.5oz of DME. Hmmmm....