I made a beer and ended up with too much water (6 gallons instead of 50 I added 4 ounces of malto dextrine, to try and add some body. The recipe called for Hazelnut extract. I don't remember the brand of the extract but after aging for a few months, the extract taste is way way too strong and the beer is pretty bad - not infected - just tastes like crap.
Instead of dumping the remaining 5 gallons, I was thinking of pouring all the bottles back into a fermentor, and adding some honey (12-16 ounces) and sugar (6-16 ounces). While that will thin out the beer, it will help raise the alcohol level a bit, and hopefully get rid of some of the hazelnut taste because of the fermentation.
I will also add another 4 ounces of malto dextrine to counter the further thinning due to additional alcohol.
(The only alternative is to let it sit for many additional months and hope the hazelnut flavor fades, but even so, the beer has too much water so I don't think it will ever be good as it is.)