Need answer fast…
Is it possible to over brine a turkey? I’m talking about a wet brine here. I’ve heard everything from 6 to 18 hours soaking in brine.
What if you left it in 19 hours? Assuming you are keeping everything cold of course…
I don’t have an answer, but I was wondering about a related question: is it okay to remove the turkey from the brine and stick it in the fridge until you’re ready to cook it, specifically to avoid too much brining?
19 won’t matter one bit. I’m using a brine that says 24-36 hours. The salinity of the solution is what sets the time for how long the bird needs to sit in the brine but it’s not a precise science.
I sure hope so, because that’s what I ended up doing.
I would guess yes. The purpose of a brine is to draw moisture into the bird. You can stop that process any time you like, although it may not be as moist.
You might want to seal the bird up so that the low-humidity environment in the fridge doesn’t suck out all the moisture the brine added.
In my experience you can’t over brine a turkey.
I usually Alton Brown’s brine and leave it in for 24 hours, once as long as 36.
No problems.
I have also pulled the bird out of the brine a day early left it uncovered in the fridge for a day to crisp the skin.
I use a flavor brine with 3 quarts apple cider, three quarts cold water, one cup kosher salt, one pound brown sugar, 4 quartered oranges, a dozen cloves, 6 bay leaves, 4 ounces of sliced ginger, and 4 crushed garlic cloves. I brine it 24 hours, then let it air dry uncovered overnight in the refrigerator. The overnight air dry make the skin crispier, that’s why I do it.
I’m also an Alton Brown briner. I do about 24 hours, and never worry too much about the time.
I see no reason you couldn’t pull the turkey out and just put it in the fridge for some extra time, as long as it isn’t TOO long. Eventually the turkey will go bad, no matter what you’re doing to it…other than eating it. 
This year, I put the turkey in the brine around 4pm, and I’ll take it out tomorrow between noon and 1pm.
I think the only way to overbrine is to oversalt the brine. If you use the right proportions, at some point the cells in the turkey and the brine outside reach equilibrium wrt salinity. After that, I think time isn’t a factor.
So to confirm, I went ahead and brined my bird for 16 hours using the Good Eats brine recipe, which suggests brining 8-12 hours, and the turkey came out fantastic.