Stuck Fermentation or Just high FG?

[nacnud]

I put a Brown Ale down a little over three weeks ago and for the last 2 weeks it's been stuck at 1.022. The Target FG was 1.015. It was an attempt at Janet's Brown Ale and I had planned to mash at 66C for 45 mins then up to 73 for 15. Unfortunately I drank a few of the previous batch before mash-in and ended up with 70C for 45 mins and 75 for 15. The grain bill was as follows:

Original Gravity (OG): 1.060 (°P): 14.7
Final Gravity (FG): 1.015 (°P): 3.8
Alcohol (ABV): 5.89 %
Colour (SRM): 20.3 (EBC): 39.9
Bitterness (IBU): 60.5 (Average - No Chill Adjusted)

75% Pale Ale Malt
7.8% Carapils (Dextrine)
7.8% Crystal 60
6.3% Wheat Malt
3.1% Chocolate

Rehydrated US05 and left at 18C for a week by which time it had dropped to 1.022. left for another week and it hadn't changed! Gave the fermenter a swirl to kick up some yeast and left for another two days but no activity. By this time I was getting pretty worried so I raised the temp to 20C and added another rehydrated packet. It's been 3 days now and still no SG change. Could it be at FG or has something gone horribly wrong? I've never managed to keep anything over 1.013 with US05 before. It tastes good but I just worried about my bottles exploding!

Thoughts?

 

[Yob]

At %18 of extras... Probably done I'm afraid..

 

[nacnud]

If it is done I'm not upset. Just don't want bottle bombs! It tastes good so I just want to get it in the bottle and in the fridge!

 

[Yob]

It's a pretty high amount of extras you have combined with a high mash temp mate... Have you tried a fast ferment test?

 

[nacnud]

I found the recipe on HBT. Fast ferment test? I don't think so... what is it?

 

[goodbeerallday]

fermenting at that temp for the last 15mins will give you some more complex sugars which the yeast will find harder to break down and produce alcohol. youll get a bit more depth and obviously more sweetness in the brew which for a brown i dont think is entirely bad..

 

[Yob]

fermenting at that temp for the last 15mins will give you some more complex sugars which the yeast will find harder to break down and produce alcohol. youll get a bit more depth and obviously more sweetness in the brew which for a brown i dont think is entirely bad..

Mashing?

 

[bundy]

You might also want to check your thermometer against some others either you are friends have. I understand if your mash gets above 70 degrees in temp you get a lot of sugars that are not converted by the yeast, hence a higher FG. Have read thermometers are pretty notorious for being inaccurate especially cheaper ones, and not much between 66 and 70. So it may be whilst you thought you were at 66 for 45 mins you may have actually been sitting a bit higher than that.

Grab 5 or 6 thermometers and check them around your mash temps 60 to 70 degrees, as that is the most important temperature you need them to be accurate at.

EDIT - just reread and see you were actually at 70. That would explain the high FG then, as per above.

 

[dr K]

In answer to your question, the ferment is clearly not stuck, it is finished (well as far as in your case it can be).
It may be that you have unfermentable sugars, and after that period of time, that mashing regime and even with with the addition of new yeast thats a fair call.
Priming sugars are not going to make your unfermentable sugars create CO2, so discount bottle bombs.
Not in answer to your question your hydrometer may have slipped paper syndrome, or as suggested your thermometer may be out, which in reality will have very little impact on your mash (unless your L:G is above 5) but will have an impact on your adjusted Specific Gravity.
K

 

[geneabovill]

Brown Ale goes lovely with Brettanomyces as a secondary yeast. And it'll dry those long chain sugars right out. Could take a while, though.

 

[nacnud]

Thanks for the replies. I have checked the thermometer in the past and it's good. I also have two Hydrometers and they are both giving me 1.022 so I guess that's as far as it's going. Will bottle up and see how it tastes in a couple of weeks. Might be interesting to have another go at getting this recipe to 1.015 and see how it compares.

Cheers!