Yeast pitching mistakes - Now what?

[Vetal]

Brewed an NEIPA about 10 days back... OG was 1.068 (Refractometer). I pitched Wyeast 1318 London Ale III yeast after cooling the wort to approx 64F. I aerated the wort (before I pitched) using a stir stick on a power drill.... Typically the recipe claims that the fermentation is done in 5-7 days with a target FG in the 1.015 range. Its been 10 days since my yeast pitch and my SG reading stands at 1.025 (tested using refractometer and converted using online calculator).. I figure - these are the mistakes I made:
1) Used a slightly older yeast - best before date was July 2021 - so I estimate it was approx half way through its shelf life ... probably a bit more.
2) Did not make a yeast starter - just waited a few hours for the liquid yeast packet to swell up and pitched directly.
3) Forgot to sanitize the packet or the scissor before opening the packet and pitching.
4) Having the wort too cool (64F) for the yeast (recommended temperature is 68F)
5) Keeping the fermenter in the basement where the current temperature is reading 64F ... so assume that the fermentation has been on the cool side for the entire duration.

So I have an attentuation of approx 68% - where I was expecting it to be 75%... the FG is still about 8-10 points off. I have raised the temperature on the fermenter using a heater (set it for 70F).

Should I assume the fermentation is finished? Should I give it a few more days at a higher temperature? I can take a SG reading again in a day or two. I still see bubbling in the airlock every 4-5 secs.... Any advice on what to do next is appreciated.

 

[MMP126]

Hey.

Yeah, you underpitched, and started the ferment pretty cold, so you will have a much longer lag time than pitching a starter at a higher temperature.

And, if you still have bubbles from your airlock, you are still 100% fermenting.

Let it ride for a few more days, and check your gravity again. Keep the temp at 70F, no lower or higher, and you should be good!

 

[bailey mountain brewer]

For the most part I agree, but bubbles don't always mean active fermentation, especially if the temp was raised.

 

[rburrelli]

Nothing sounds exceptionally wrong with the yeast. I might look at how you mashed before blaming the yeast.

 

[hotbeer]

I wouldn't expect the refractometer measurements to necessarily match a hydrometer reading even when corrected. But for simply telling if fermentation is stopped and the SG not moving it's probably accurate for that.

If you have a hydrometer, use it and see if it's different if you really want to be certain of your FG.

As far as letting it sit longer... sure, probably better IMO to go longer than shorter.