3 weeks - high FG, sweet porter

Brewed my 1st BIAB AG batch (2nd batch ever) EdWort's Bee Cave Porter 3 weeks ago today. Was planning on bottling tomorrow so I checked the FG. Turns out it was about 7 points too high and the sample was very sweet. Here are my notes:

Batch Size 2.75
Expected OG - 1.061
Expected FG - 1.015
IBU 38.85

Actual OG - 1.056
Actual FG - 1.022


5.5# 2-row -79.64%
0.5# Chocolate malt - 7.24%
0.5# Crystal malt - 7.24%
4 oz flaked barley - 3.62%
2 oz black patent - 1.81%
0.5 oz roasted barley - 0.45%

0.5 oz norhtern brewer - 60min
0.25 oz cascade - 60min
4oz malto-dextrine 20 min

1 pkg London Ale Yeast

My target mash temp was was 152, when I checked it after 15 minutes it was 156 so I added some cooled water.
I did a dunk sparge with what turned out too be too much water by ~ 0.35 gallon.
My preboil OG was a little high, but I over-estimated my boiloff so my actual OG was only 1.056
I hadn't yet purchased my immersion chiller so it took ~ 1hr to cool to 70*
I pitched then fermented around 65 (some small fluctuation when I wasn't around to change out the frozen water bottles)

Questions:
1-Anything obvious that would cause the apparent low attenuation/high FG?
2 - Any way to fix that sweetness other than carbing it up and hoping for the best?

the yeast is a lower attenuator.

the mash temps spiking may have caused some unfermentables, but it sounds like you caught that quickly and corrected.

Looks like you came out pretty good on the numbers and is the style a "Sweet Porter"?

Isn't a sweet porter supposed to be sweet? Pitching a higher attenuating yeast or even some amylase enzyme could dry it out some but you run the risk of changing the flavor. I would not change it but that is just my opinion!

Good luck

No I suppose that title was a little misleading, I was only referring to the taste of the sample - I think EdWort calls it a Robust Porter.

Hmm, that does make a little difference. What about throwing in a package of Nottingham? That may dry it out a bit more without changing the flavor too much.

woops-see below

Did you notice a weak krausen? Not that i think it matters but Thats what im getting now, i also harvested/washed yeast with 2 oz slurry and only pitched the seperated yeast,maybe i should have just threw in the whole 2 oz slurry. I dont know if i underpitched or not I used wlp005 and that yeast does not like to start below 70.
I would try swirling carefully and getting your temps up 5 more degrees and check to see if it drops in a week. I wouldnt pitch more but thats up to you,make shure your boil thermometer is accurate also. If your going to pitch nottingham i wouldnt raise it to 70 though just in case you were thinking of doing both. Let us know what happens if you decide to pitch nottingham.
Like somebody else said if its a low attenuating yeast that is why,is this what Edwort used in the recipe?
EDit:
I just looked at the recipe and he used nottingham. I wouldnt repitch my self just because i dont know how that would work at 3 weeks; Unless you dont want to have a sweet stout-just like you titled.Maybe it was meant to be?
Your looking at 4.4% abv,im shure it would turn out really good either way.

Krausen looked good and was very active for a few days

I just brought the carboy to a spot that stays closer to 70, suppose I will leave it there until next week.
Yeah, he used nottingham in the recipe. When I went to the LHBS I didn't have the yeast listed on my shopping list, so London Ale was recommended to me.

I calculated my attenuation to be about 61%. Wyeast lists London Ale as 73-77%. This is my first time looking at this kind of information but that makes it seem like it should have come down further.