At best if you were to average around the 155f mark I would say from experience that your FG would range around 1.012-1.015 at a high again varying on average SG. Most times a high depending on yeast would be closer to 1.013 depending on grist. You had mostly base, so grist was not an issue here. Your temp should be fine for Nottingham and the 70’s should have kicked it up.
I would hope for 1.015 at this point from all indications.
Are you sure you have calibrated your hydrometer and are compensating for temps etc…Its really a 50/50 game with hydro’s and over the years I have had ones that read -/+ 1.001-1.005 as sometime the paper shifts inside during handling is my thought.
Most hydro’s will read 1.000 @ 60f with low/ no TDS H2O. If in question just look at yours as it will say.
Now if you plan to bottle condition, I would be very leary of adding additional sugar and/or would myself add more yeast to primary to get this SG down to norm as you will have “bombers” for sure if you add additional bottling sugar now. I don’t have a chart handy but in the past when I checked the “sugared” wort prior to bottling it was only 1.003-1.005 higher than terminal to hit around 2.5 volumes.
If you are 1.006-1.010 higher than terminal (depending on mash temp/ grist again) right now and were to bottle, just a real wild guess is you would carbonate in the bottle to around 3-3.5 or higher volumes which may or may not cause issue. If you wish to just salvage this batch without much todo I would do the following.
Just leave the wort unsugared and add like a half/quarter pack of fresh yeast and fill some plastic 12/20 oz pop bottles and then test one at 7 days, 14 days etc… and when they are carbed up then put them all in the fridge to try to stabilize at the current volume you wish plus if just moving forward in this way then they should “dry” out and not be sappy sweet.
According to the danstar technical data sheet, they claim attenuation to 1.008. In my limited experience, I’ve usually end up around 1.018-1.020 when using this yeast. [/quote]
No way, It will always ferment close to 1.010 unless you used alot of dextrin malt/ mashed only at/above 158f or used other unfermentables in the grist OR your making strictly extract based beers as this can cause high FG but usually no higher than 1.015 unless your making really high gravity beers or something else in combo like I will mention below.
The only Diff if you happened to overlook at some point and used without noticing etc… is Danstar Windsor yeast. As this other British yeast is a very low attenuator and will always leave beers at least 1.003-1.005 higher than Nottingham.