Chai Latte Stout stalled

[Waynealford]

Followed the recipe exactly, using S04 yeast at 18 degrees.  Started at 1.060, the recipe reckons 7-10 days to ferment out to around 1.015ish, but after 8 days it is still 1.030!  Considering the majority of the fermentation should happen in the first few days, not sure what is going on.  Should I tweak the temp UP a little bit (it says 18-20), or pitch some more yeast?

[Hairy]

S-04 has a reputation for stalling so I like to ferment it a little warmer at 20 degrees.

Probably best to pitch some more yeast and increase the temperature a little.

[Waynealford]

Advice from LHBS is to dissolve about 1/3 cup of sugar in warm water, pour in gently, then up the temps to wake the wee beasties up!  He reckons they're not dead, just exhausted, so maybe some food and some warmer temps will kickstart them [I'm paraphrasing, obviously] .  Can't get in contact with Coopers helpline yet...….

Thoughts?

[Hairy]

28 minutes ago, Waynealford said:

Advice from LHBS is to dissolve about 1/3 cup of sugar in warm water, pour in gently, then up the temps to wake the wee beasties up!  He reckons they're not dead, just exhausted, so maybe some food and some warmer temps will kickstart them [I'm paraphrasing, obviously] .  Can't get in contact with Coopers helpline yet...….

Thoughts?

You can definitely do this. You can also give the batch a very gentle stir to get the yeast back in suspension too, but avoid splashing and vigorous stirring.

[Waynealford]

Sugared, stirred, foamy!!  Checked on it this morning at 22 degrees, nice and foamy.  Would still like to understand why it happened, so I can avoid it in the future.

[Beerlust]

Hi Wayne.

Stalls generally occur as a result from either not pitching enough yeast to ferment out the required gravity of wort, or as Hairy has already mentioned, the ferment temperature is a little lower than the yeast strain likes to operate in.

In your case 11.5gms of yeast should be ample to ferment 8.5 litres of 1.060 wort, so the lower ferment temperature combined with the S-04 is the likely cause. S-04 is notorious for going to sleep if fermenting below approx. 20°C. I've experienced the same situation as you have with it, & a gentle re-rouse of the yeast & raising the ferment temperature is generally enough to get it back & fermenting.

Best of luck with the brew.

Lusty.

[Waynealford]

26 minutes ago, Beerlust said:

Hi Wayne.

Stalls generally occur as a result from either not pitching enough yeast to ferment out the required gravity of wort, or as Hairy has already mentioned, the ferment temperature is a little lower than the yeast strain likes to operate in.

In your case 11.5gms of yeast should be ample to ferment 8.5 litres of 1.060 wort, so the lower ferment temperature combined with the S-04 is the likely cause. S-04 is notorious for going to sleep if fermenting below approx. 20°C. I've experienced the same situation as you have with it, & a gentle re-rouse of the yeast & raising the ferment temperature is generally enough to get it back & fermenting.

Best of luck with the brew.

Lusty.

Thanks Lusty.  My only rhetorical question would then be, if S-04 is notorious for stalling under 20 degrees, why the hell would the recipe specify S-04 @ 18-20? Are they trying to make problems???

[Beerlust]

9 hours ago, Waynealford said:

Thanks Lusty.  My only rhetorical question would then be, if S-04 is notorious for stalling under 20 degrees, why the hell would the recipe specify S-04 @ 18-20? Are they trying to make problems???

Some brewers have no problems fermenting S-04 @ 18°C, where others run into this stall scenario if they attempt to ferment at this temperature. I could only speculate on possible reasons for this, so it's just easier to play it on the safe side (from my perspective) & ferment a brew with S-04 @ approx. 20°C to avoid the chance of this happening.

One could say S-04 is a temperamental yeast. 

Cheers & good brewing,

Lusty.

[Waynealford]

Bottled it last night on advice from Coopers and LHBS.  Didn't move from 1.028 in the 6 days since sugaring, so with bottle conditioning, will only be about 4.5% ABV, instead of the advertised 6.5%.

Longer term bottling should mellow out flavours and make it a smooth drop, looking to do another fancy stout for the missus, but a little gun-shy from this one.  Will ponder......

[Shamus O'Sean]

Hey @Waynealford, one to consider that there was good feedback on is the Island Toasted Coconut Porter

[YeastyBoy]

In my experience is it can be a slow ride with S04.

My Extra Stouts normally start at 1056 and finish at 1014.

Can take 3 weeks at 18c to get there as they tend to really slow down fermenting after a week.

I just apply the Don't Panic motto and wait it out. Works for me.

Cheers YB