Stout stuck fermentation ?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ozgu

Member
Joined
Oct 6, 2018
Messages
16
Reaction score
0
Hi there,
I made my beer at 16/01/2019 with an 1,121 o.g., and when i checked the s.g. after 13 days it was about 1,041-1,042. Temperature stayed at 18-19 C most of the time.
So, today, after 60 days of fermentation i thought that gravity should be down to about 1,035s, and i can bottle the beer. But, when i checked the gravity with a hydrometer, there was nearly no change after my previous s.g, it stayed at 1,040.
So, is it about amount of unfermentable sugar, or fermentation temp./yeast, or anything else ?
Also, there is not any sign of infection. Its look, and taste pretty normal.
I used 2 package Us-05, without starter. Batch size about 18,5 liters.
And here is the list of fermentables:

11.6 kg German - Pale Ale 78.4
0.79 kg German - CaraAroma 5.3%
0.4 kg German - CaraFoam 2.7%
1 kg German - Carafa III 6.8%
0.675 kg German - Carafa II 4.6%
0.25 kg German - CaraRye 1.7%
0.075 kg German - Melanoidin 0.5%

Thank you.
 
Last edited:
I would say you're fermentation is pretty much done. You're at 10.5% ABV right now. Trying to get yeast to eat that last little bit of sugar will be difficult. You could do one of the following if you wanted:

1. Pitch a starter of some more yeast of your choice. Pitch the starter at high krausen (12 hours?) and hope that will eat the rest of the sugars.
2. Pitch some champagne yeast like EC-1118. This wouldn't affect the flavors of your stout. You've already gotten the character from the US-05 and the fermentation that already happened with the yeast. The EC-1118 would just eat a small amount of sugar and shouldn't change your flavor profile.
3. Leave it as is and finish it from there.

My first RIS stalled at 1.050 and wouldn't budge. I tried option 1 & 2 above, as well as adding some rehydrated US-05, and it did nothing. I've seen a few posts on this forum where people ran into the same problem just recently and couldn't get it to budge.

The problem is that it's such a toxic environment for the yeast at this point that getting them to do anything is going to be very difficult.

My personal opinion is leave it as is. Once it's carbonated, I bet it'll still taste good. I can't sit here and tell you that you WON'T notice the difference between the beer finished at 1.040 and 1.035, but you might not be able to tell the difference.

In the future, not sure how you aerated the wort but a beer like that should be aerated VERY well. Additionally, people will usually aerate at yeast pitch, and then again 12 hours later. Big beers like this require the extra oxygen for healthy fermentation. I'd also bump it up to maybe 3 packs of US-05.
 
I would say you're fermentation is pretty much done. You're at 10.5% ABV right now. Trying to get yeast to eat that last little bit of sugar will be difficult. You could do one of the following if you wanted:

1. Pitch a starter of some more yeast of your choice. Pitch the starter at high krausen (12 hours?) and hope that will eat the rest of the sugars.
2. Pitch some champagne yeast like EC-1118. This wouldn't affect the flavors of your stout. You've already gotten the character from the US-05 and the fermentation that already happened with the yeast. The EC-1118 would just eat a small amount of sugar and shouldn't change your flavor profile.
3. Leave it as is and finish it from there.

My first RIS stalled at 1.050 and wouldn't budge. I tried option 1 & 2 above, as well as adding some rehydrated US-05, and it did nothing. I've seen a few posts on this forum where people ran into the same problem just recently and couldn't get it to budge.

The problem is that it's such a toxic environment for the yeast at this point that getting them to do anything is going to be very difficult.

My personal opinion is leave it as is. Once it's carbonated, I bet it'll still taste good. I can't sit here and tell you that you WON'T notice the difference between the beer finished at 1.040 and 1.035, but you might not be able to tell the difference.

In the future, not sure how you aerated the wort but a beer like that should be aerated VERY well. Additionally, people will usually aerate at yeast pitch, and then again 12 hours later. Big beers like this require the extra oxygen for healthy fermentation. I'd also bump it up to maybe 3 packs of US-05.
Thank you for your reply, much appreciated. As you wrote, it stuck, probably because i did not aerated it well.
At this point the thing is, if i add proper amount priming sugar, and bottle it, is there any probability that becoming bottles over carbonate and make them explode, due to high f.g. ? Or, there is no need to consider f.g., since yeast done with residual sugar?
 
Thank you for your reply, much appreciated. As you wrote, it stuck, probably because i did not aerated it well.
At this point the thing is, if i add proper amount priming sugar, and bottle it, is there any probability that becoming bottles over carbonate and make them explode, due to high f.g. ? Or, there is no need to consider f.g., since yeast done with residual sugar?

To be 100% honest, not sure. My thought is that you should be fine, but you should take precautions just to be safe. Bottle it as normal, but after it's bottled, store the bottles in some kind of "hard" container, like a rubbermaid bin or something, while they're carbonating. This way, if you DO have bottle bombs, it helps keep it contained. Once they are carbed up where you want them, I'd put the majority of them in a fridge to keep them cold which will keep them from continuing to carbonate and exploding. You could then leave a few bottles out at room temperature, still in the hard container, and just let them go for a month or two and see what happens. If they don't blow up, you should be good with the rest of them as well.
 
To be 100% honest, not sure. My thought is that you should be fine, but you should take precautions just to be safe. Bottle it as normal, but after it's bottled, store the bottles in some kind of "hard" container, like a rubbermaid bin or something, while they're carbonating. This way, if you DO have bottle bombs, it helps keep it contained. Once they are carbed up where you want them, I'd put the majority of them in a fridge to keep them cold which will keep them from continuing to carbonate and exploding. You could then leave a few bottles out at room temperature, still in the hard container, and just let them go for a month or two and see what happens. If they don't blow up, you should be good with the rest of them as well.

Ok then, i will try it. Nonetheless i am pretty nervous, hope that they will not explode or something.
 
Good luck. Let us know how it turns out. Remember, keep them in a hard container until you're sure you aren't going to have bombs.
Since i was busy a bit, i will bottle today. And i have got a quick question, should i add some fresh yeast while bottling ? I have seen before that it suggested for high abv beers.
 
Back
Top