Another stuck fermentation question

[griffi]

I brewed a RIS on Jan 10, so 3 weeks ago. It was an extract kit from NorCal Brewing. Nice kit, I pitched the two packs of S-05 into the well oxygenated (fish pump not pure O2) wort at 1.102 OG. Bubbled like crazy for a week at about 66 degrees, and bubbled away for another week more slowly but now seems to be stuck at 1.036. I raised the temp to 68 then 70 but it doesn't seem to be responding. It's supposed to get down to 1.023. Tasting the hydro samples, it's way too sweet. Any suggestions of what to do with it at this point? I'm inclined to try to pitch more yeast in an effort to save it.

 

[didinho]

I brewed a RIS on Jan 10, so 3 weeks ago. It was an extract kit from NorCal Brewing. Nice kit, I pitched the two packs of S-05 into the well oxygenated (fish pump not pure O2) wort at 1.102 OG. Bubbled like crazy for a week at about 66 degrees, and bubbled away for another week more slowly but now seems to be stuck at 1.036. I raised the temp to 68 then 70 but it doesn't seem to be responding. It's supposed to get down to 1.023. Tasting the hydro samples, it's way too sweet. Any suggestions of what to do with it at this point? I'm inclined to try to pitch more yeast in an effort to save it.

S-04 or US-05?
mash temperature?
how many liters?

 

[bransona]

+1 on the questions above. Could easily be mash temp or yeast

 

[griffi]

This a 5 gallon extract batch, so there was no mash per se but I steeped the specialty grains for 30 min at 155 IIRC... I pitched two hydrated packets of S-05.

 

[griffi]

What do you think about pitching another pack of S05 this late in the game?

 

[griffi]

To follow up, I tried several times even making a starter from a pack of S05 and trying to train it to eat the RIS, but finally the other day I put a tsp of amylase extract and dumped a 1.2 liter starter of WLP001 in there. I've had 2 days of active fermentation now and I'm feeling confident I've escaped from stuck mountain as some other poster called it. This is great because it's going to be very tasty when it's down another 13 points!

 

[IslandLizard]

Just be prepared, the enzymes may chew it down 20 points... or 30. No way of telling. Chances are the alcohol level will stop the yeast at some point.

Many extract brews seem to stall around the dreaded 1.020, so your super high gravity RIS is following that trend. It may have to do with insufficient oxygenation or vitality of the yeast, or a combination of factors.

 

[griffi]

Understood. I'm hoping it stops at 1.23 or so. I'll monitor and if it goes to 1.020, I'll cold crash and keg it. I had been hoping to bottle condition this but now that I've used the enzymes that is less likely.

 

[Calder]

Nothing to add, I just want to see how this turns out.

 

[DurtyChemist]

Pitch a vial of Brett

 

[griffi]

Nothing to add, I just want to see how this turns out.

Honestly that's kinda how I feel about it at this point

 

[BarrelAgedForrest]

Update on this one? I have an RIS that started at 1.106 that's been going a few days now and am curious to how this turned out in case mine stalls.

 

[JosephN]

What is an RIS?

Also I saw a video the other day saying that dry yeast doesn't need to have the wort oxygenated due to the yeast already having something that liquid yeast needs the oxygen to create. The guy said he was reading it from some paper he had, I don't know where the info came from, but it sounded convincing. And I would think that you probably needed 3 packets of yeast for a sugar content at 1.106. I brewed a 6 gallon batch of an Irish red ale and used that yeast cake to ferment a barleywine, while the yeast was still pretty fresh, and it fermented down about .006 points lower than expected. I'm letting it bulk age another week or two before bottling. When I do bottle it I'm gonna use a fresh package of WLP001 to carbonate.


Now what are the enzymes you are talking about that got "used up"?

 

[griffi]

Well, your request for an update sent me for my hydrometer. I'm happy to say that it has been bubbling slowly since adding the yeast and amylase enzyme. It seems to have been getter slower over the last week and it is now down to 1.028. I'm going to see where it goes for another week. Hopefully it will stabilize rather than keep going down...