I brewed a blonde ale with extract a little over a month ago. I fermented in primary for three weeks and have been bottle-conditioning for two weeks. I didn't take an OG, but the final gravity before bottling was 1.011 (exactly what the recipe called for). I cracked one open this morning to give it a taste, and while it's good, it has a distinct, syrupy taste similar to green apples. Any ideas what might have caused this? Is this a taste which will likely mellow out with time?
Green apple flavor is called Acetaldehyde. It's one of the off-flavors that can dissipate over time, though it can be caused from a bacteria that won't go away.
I would certainly wait awhile to see if the flavor dissipates.
Green apple taste can be caused by acetaldehyde, which will generally mellow out over time. Iirc, it's a middle-compound between sugar and alcohol that the yeast still needs to work on.