Stalled Ferment - Usual solutions already tried

[trussyd]

I've two bitters in fermenters at the moment that have both stopped at a FG of 1030. The malt bill was the same on both of them, 90% ale and 10% dark crystal to an OG of 1045. Single step mash at 68C for an hour.

Both were aerated before pitching using my new aeration pump.

Yeast was an old sample of 1469 that I had saved from a previous batch. It was very old so I built up a big starter (6L in total) and decanted before pitching. The starter took a while to get going but was pretty active by the end. After decanting I split it and made a starter with some of the wort which was then pitched into the main batch while still active.

I was fermenting pretty low, about 17C, as I didn't want the yeast to give too much flavour to the finished beer.

I've given it a swirl to try and rouse the yeast the last couple of days and have also upped the temp to 19C to try and get it going. Still nothing.

Hydrometer is correct. I've calibrated and cross checked. The beer is still very sweet too, so I'd say 1030 is about right. Temp probe is correct too.

Has anyone else had experience with 1469 packing up its bat and ball and refusing to play anymore? In the past I've had issues with it going too hard and making a huge mess everywhere, which was part of the reason I kept it so cool.

Also, any suggestions on where to go from here? I don't have any more 1469 but I do have some US05 I could throw at it to finish the job...?

 

[Camo6]

Are you certain of your mash temps? Maybe your method of measuring mash temps is way out and the beer is finished?

If it is a stalled ferment you could try a fast ferment test. And if you do repitch, do it with a starter at high activity to give it the best chance.

What was your batch size?

Have you searched "stalled fermentation" or "high final gravity?" There's a few threads with advice that's helped me before.

 

[warra48]

If and when you repitch, use an active starter of an adequate size, but do not aerate your main batch. You are not looking for growth, just fermentation.