IPA really bitter

10 days after bottling or 10 days into fermentation?

If it's into fermentation I wouldn't worry. IPAs always taste very bitter to me when still but after conditioning are fine.

 

Like what was said above, Pisa are bitter at first, then mellow some so I believe you'll be fine 10 days to 2 weeks after bottling or legging.

 

Bitterness is probably related to such a long steep overnight. How long was it from the end of boil to when the wort was cooled down?

 

Tons of questions here... This is a 5 gal batch? How long before you started chilling? Did you chill by just placing the pot in the fridge? Alpha acid%s on the hops? With just a guesstimation, you landed at 65 IBUs if you chilled immediately. That's in the ball park for an IPA…but again depends how long it took to slow down the isomerization rate of alpha acids.

Other possible things are culprits are hardness levels of your water…astringency from tannin leach….

 

This is your problem. Have to cool relatively quickly or else so much alpha acid will isomerize into the wort and over-bitter your beer.

I've done this recently with a new system that I now cool in ice bath as opposed to counter flow chiller I used to use. I will now change my flameout hops to a whirlpool hop addition when the beer cools down to 180F I will add them and whirlpool until 65F for pitching.

 

I wouldn't dump it. I'd go ahead and bottle it, but you may have to give it extra time after carbonation to further condition the flavors in the bottle. Hop flavors (and I assume hop bitterness too) always take a bit longer to reach their peak taste before beginning the mellowing and declining process. It may not be the best beer that you'll ever brew, but maybe it will be, and you won't know the answer for another month.

P.S. Welcome to the BA site and to the Homebrewing forum. We're glad that you're here.