Adding hops for bitterness after fermentation starts?

I have a very high gravity beer fermenting right now, but feel like I should have added more hops for bittering to the boil. Its an Porter with a SG of 1.097. Besides dry hopping, which I understand to be for aroma, is it possible to boil additional hops in water and add after fermentation begins for bitterness? Is there any other way to correct this after the fact?
Thanks in advance for any help/tips!

Yes, you could try that. Some told me about using a french press for adding hops flavor but I"m not sure how it works for bittering flavor.

If the beer is too sweet, you could try boil some hops in some water for an hour and seeing if that fixes the issue.

You could try to make a hop tea in a french press. Use boiling water. You'll get some bitterness, not sure how much.

You could try making a hop extract in ethanol. You could soak some hops (high alpha would be most effective) in vodka or other neutral spirit. You will end up extracting compounds besides the bittering acids, but to what extent they will contribute flavors I'm not sure. For the commercially produced stuff they boil off the ethanol from the solution, which will isomerize (some) of the acids. If you go this route you should definitely try a few drops in a sample; it's apt to be brutally bitter, as ethanol extraction is much more effective than boiling.

french press + hops will add a lot of bitterness post ferment. I once steeped 0.5 oz Centennial in keg and it was noticable.

I'd say leave it until it's done fermenting, taste it, and then decide whether you need any more bitterness. You can certainly boil hops in water (or a weak ~1.020 wort) to get bitterness, but I'd start with less than you think you need. You can always add more in a couple days if you feel it's not bitter enough, but if you overshoot it you'll just have to wait it out.

Thanks for alot of really good input. I think I may wait it out like suggested and then add if I think its needed at that time. Its a BIG beer so I'll be waiting for awhile yet but I will keep you all posted as to what I end up doing.

How many IBUs ans what style is it?

Hi Daver77...to the best of my calculations, the IBU's is right about 26 and it is a Porter. I don't know alot about determining the IBU's but I used a tool from The Screwy Brewer and came up with 26. Also according to this tool they suggest the IBU's to be around 64. Does that sound about right?

I have just done the same thing to my beer. I did a partigyle and way overboiled the big beer down to 1.120. I guess i will wait and see how this tastes after fermentation is over and maybe when I rack to clear it, I will possible add a hop tea.