Stuck Fermentation

robcoombs · January 21, 2015, 05:50:50 PM

Why do I find myself posting problems so often

I brewed a RIS about a week and a half ago. OG 1.080. After 6 days it had reached 1.033, I checked it two days later and it is still only 1.031 and seems to be stuck there. I've tried rocking the carboy, increasing the temp to 21C, gently stirring a few times to rouse the yeast. Two days ago I pitched another pack of rehydrated US05, SG is still 1.031. I'm going to try adding some yeast nutrient mixed with water and dextrose tonight. Anyone have any other suggestions. I really don't want to dump this batch, it tastes pretty good aside from the obvious sweetness.

paulmaybee · January 21, 2015, 06:01:21 PM

Would it help to aerate the beer by racking it again?

robcoombs · January 21, 2015, 06:26:52 PM

Aerating the wort at this point would cause oxidation I believe and cause that paper/cardboard off flavor.

paulmaybee · January 21, 2015, 07:02:53 PM

I don't know, I kinda liked it.

Roger · January 21, 2015, 07:47:41 PM

I don't know what to suggest. I seam to always have the opposite issue with my final gravities going lower than 1.010. I hope your idea of using yeast nutrient with dextrose works out for ya.

robcoombs · January 21, 2015, 07:57:20 PM

I normally get under 1.010 as well. This is the second time I've used US 04, and each time I've gotten a stuck fermentation. Though last time was 1.022

Two Wheeler · January 21, 2015, 07:59:30 PM

S-04 is usually a beast for me.

https://byo.com/stories/issue/item/3170-stuck-fermentations-techniques

QuoteWhat we need to add is some fresh yeast that can pick up the baton from the tired cells and complete the race. But just tossing in more yeast is unlikely to work, because there is no oxygen present to help yeast growth, but there is sufficient alcohol present to "poison" the yeast and reduce its vitality. Instead, the yeast must be in active, vigorous growth phase when it is added to the beer. And that means (yes, you've guessed it) adding a fresh starter. This technique is called kräusening.

robcoombs · January 21, 2015, 08:18:41 PM

Thanks for the link. I did read that AFTER I pitched another pack. I'll try the yeast nutrient tonight. If it hasn't changed by the weekend I'll try pitching a starter. This is starting to become an expensive batch.

Al-Loves-Wine · January 21, 2015, 11:42:48 PM

This seems similar to the Scottish Heavy I just made awhile back, it was 1.084 and after 10 days of primary holding 1.028 I figured it was done. Racked it over to secondary to age it, and the the rest of the yeast flocculated out and finished fermenting. S04 is high flocculation with a rated attenuation of 75% and from 1.080 should get you somewhere near 1.020 @ 75% so might be just a sit back and wait, if you can secondary it and put it in a closet if all else fails.

jamie_savoie · January 22, 2015, 10:08:37 AM

One tip when making a big beer is to use a second generation yeast and use the whole yeast cake (and don't worry overpitching). That's the way I always do my big beer.
And like Al said, give it time. Patience you must have, young Padawan

wy3711 or belle saison is a very for stuck fermentation but make sure it's alive and active. Brett is also good to chew up some unfermentables. Krausen from an active fermentation would work very well too

robcoombs · January 22, 2015, 11:24:49 AM

Quote from: jamie_savoie on January 22, 2015, 10:08:37 AM
One tip when making a big beer is to use a second generation yeast and use the whole yeast cake (and don't worry overpitching). That's the way I always do my big beer.
And like Al said, give it time. Patience you must have, young Padawan
wy3711 or belle saison is a very for stuck fermentation but make sure it's alive and active. Brett is also good to chew up some unfermentables. Krausen from an active fermentation would work very well too

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