Stalled at 60% attenuation

[Leard]

I recently brewed a chocolate brown ale:

2.88kg Pale ale
0.66kg Munich I
0.33kg Carared
0.26kg Melanoidin
0.21kg Chocolate
0.41kg Lactose
217g Cocoa pwder

1 pack of Mangrove Jack's M42

OG was 1.051 so Beersmith estimated an FG of 1.016. It's been 18 days now and I'm stuck at 1.020, it's been at that for a week. I've tried adding some yeast nutrient. I've tried increasing the temperature. I've tried swirling it to get some of the settled yeast back to the top. I've also tried adding some old Nottingham yeast that's been stored in my fridge for a while, that could likely be dead however. I'm not sure what else to do now. Should I just accept quite a high FG or is there anything else I can try?

 

[kelper]

Try adding some hop pellets or some amylsase

 

[dillz2003]

In my experience Beersmith isn't that good at estimating FG when lactose is used in the recipe. 1.020 could be as far as you get with the lactose in there.

I had the same problem a few months ago with a Russian Imperial Chocolate Stout that started at around 1.1 and stuck at 1.039 and I got it going by adding WY3711 saison yeast, also specifically recommended by Wyeast to start a stuck fermentation;

https://wyeastlab.com/yeast-strain/french-saison
It finally finished at 1.020, with no saison taste I should add, although I would have been happy with anything under 1.025 in the end.

Given the cost of the yeast I duplicated it first in DME and have since made two gorgeous saisons with it, something I never considered doing before. I did consider Amylase but I was worried it would run riot, converting everything in sight to a fermentable sugar and not know when to stop, which i felt would alter the character of the beer and i didn't want a dry stout!

Anyway I went for 3711 and it worked a treat. Your 1.020 doesn't seem too bad but I can understand why you might want it a bit lower. Does it taste too sweet? If it tastes OK I would feel inclined to leave it and see how it conditions.

 

[Leard]

I've since kegged the beer and it's really good. The 1.020 gives it a lovely thick mouthfeel that you want from a milk chocolate beer. It's definitely a dessert beer. I'll have to bare that in mind next time I brew something with lactose in on Beersmith.

 

[dillz2003]

Sounds lovely! I'm sure it will get even better as time goes on. From my own experience and from a lot of stuck fermentation threads quite a few people struggle when lactose is involved.

 

[Keruso]

I recently brewed a chocolate brown ale:

2.88kg Pale ale
0.66kg Munich I
0.33kg Carared
0.26kg Melanoidin
0.21kg Chocolate
0.41kg Lactose
217g Cocoa pwder

1 pack of Mangrove Jack's M42

OG was 1.051 so Beersmith estimated an FG of 1.016. It's been 18 days now and I'm stuck at 1.020, it's been at that for a week. I've tried adding some yeast nutrient. I've tried increasing the temperature. I've tried swirling it to get some of the settled yeast back to the top. I've also tried adding some old Nottingham yeast that's been stored in my fridge for a while, that could likely be dead however. I'm not sure what else to do now. Should I just accept quite a high FG or is there anything else I can try?

With that amount of lactose you’re unlikely to get anything less than 1.020, it’s unfermentable sugar.