Finicky Wyeast 3724 Stall

Question

Looking for some useful suggestions. I’m a veritable noob when it comes to brewing. I’m on my second brew and already trying to experiment with my own recipe albeit sticking to extract / specialty grains.

Trying to do a saison style beer and landed on Wyeast 3724 for my chosen yeast. Brew went relatively straightforward and hit my target OG on the nose @ 1.062.

Into 5gal glass carboy for primary, pitched yeast and fitted blow off tube. A day in and super glad I used a blowoff as kreusen to the brim and into the tube.

6 days into fermentation and activity completely ceased. Took a sample and OG only dropped 20 points to 1.042.

Now I’ve since read about problems that come with this yeast and that it is know to start vigorously and stall out around this point sometimes for weeks and weeks.

I also didn’t know about the high temps need for the yeast so the first week was done at 18c. At day 8 or 9 I ramped temps to 27c and held it there since. Now 16 days in and things are moving painfully slow. I’m in no rush but keep second guessing it and thinking I should dump and start again, perhaps with 3711 instead.

I don’t want to pitch another yeast (but would use US05 if I did). So aside from the temp increase I’m thinking I could rouse the yeast some way.

That’s where my question comes in - any suggestions about how to rouse it? I can’t give the FV much movement as the kreusen really caked onto the glass and I don’t want any of that to mix back into the wort. Is there anything else I could try?

If it helps, recipe was:

8lbs extra light DME 1.25lbs Crystal 20L 1lb clear Belgian Candi sugar

Steeped crystal for 30 mins @ 160f

60 min boil of 3gal topped off with water to make 5gal total in FV.

Answer 1

The Saison strains are very sensitive to CO2 toxicity. Most of the CO2 produced during fermentation escapes out the airlock but some of it does dissolve into the beer. (A taste test of a small sample of any fermented beer will be slightly carbonated as a result of this).
Swirling the fermentor occasionally during the fermentation process agitates the solution and CO2 will come out. You will see the airlock gurgle away. After a couple days of this the ferment will restart and finish the beer. The reason why the high temp concept works is not that the yeast need heat. It works because the increase temp decreases the solubility for CO2 in solution. The CO2 comes out and the yeast start to ferment again.
This has been my experience with side by side testings. Do it carefully as to NOT introduce new oxygen into the beer. There should be enough CO2 escaping to prevent it from happening as long as you are not overly aggressive. (i.e. don't think opening a bucket fermentor and stirring it is better than shaking.)

Answer 2

Obviously too late to help you, but I've used 3724 extensively and never had the stall after reading an article about saison yeasts by Drew Beechum. He said that 3724 doesn't perform well under pressure and recommended using a sanitized piece of aluminum foil placed loosely over the fermentation vessel. I use a Ss Brewtech bucket and just lay the foil over the top. I also run the temp up to 90 plus degrees and up to 100 degrees with no ill effects and no stall at all. 3724 isn't the vigorous fermenter that 3711 is, but I get no stall.

Answer 3

My suggestion would be to shake the FV and just mix the old krausen back into the beer. It came out of the beer in the first place, and it should not have any significant impact on the end result as it drops out. Besides, it could be beneficial for the yeast to introduce some fresh oxygen.

How much volume did you brew? In general one smack pack is not enough for a 5 gal beer of this gravity. Belgian strains tent to produce lot of phenols and esters when under pitched and are prone to stalling.

So shake it, keep the temp high and wait a few days for it to take off again. If it doesn’t, consider pitching that us-05. Most of the yeast phenols and esters that give the saison its character, are produced in the first days (or hours) of fermentation, during the yeast growth period. Adding a neutral yeast like us05 wont impact the end result much I think.

Answer 4

Just be patient. This is a known issue with this yeast when fermented at lower temps. Most times it will wake back up and finish out after a few weeks. If it doesn't, many labs suggest using a clean fermenting strain like White Labs WLP001 to finish fermentation.