Slow fermentation with multi-grain recipe

I’m brewing a clone of Pretty Thing’s Field Mouse Farewell, recipe below. I started with Wyeast 3724 Belgian Saison, which had a visually normal kick in the first couple of days - everything looked fine. I didn’t get a measured OG because my graduated cylinder broke, but I’m guessing in the 1.070s based on a calculated OG. It was in primary for a week+, in secondary for three weeks during which there was a steady white foam on the top. Racked to keg, at which point I had a graduated cylinder, and discovered the SG was 1.064.

Time in the secondary was during very cold weather, wort was probably in the low 60s. After a week in the keg, I racked it back to secondary thinking that temp was the issue, threw in a pack of Wyeast 1968 ESB (this actually matches what I can find for the original recipe, believe it or not), put a heating pad on it and brought it up to 70F. No head formed, but fermentation continued based on airlock. Checked SG 2 weeks later, now it’s 1.050. I’ve tasted it all along and while it’s funky like you’d expect from that grain bill, it seems otherwise fine. After being in the keg, it’s very nicely carbonated, even after going back into the secondary.

I’ve used Wyeast 1968 dozens and dozens of times, it’s been very reliable and vigorous across a wide range of temps and at that SG range. Why wouldn’t it have taken off? And why would the original Saison pitch not get it done? Is there something about the other grains that might be inhibiting fermentation?

Any thoughts much appreciated. This is a great beer, I really want to figure out how to make it.

  • Gregg

Field Mouse Retreat clone

13 lbs Belgian Pilsner Malt
12 oz Briess Rye Malt
8 oz flaked wheat
8 oz flaked oats
1 oz UK Bramling Cross (60 min)
1 oz UK Bramling Cross (40 min)
1 oz French Strisselspalt (30 min)
1 oz French Strisselspalt (flameout)

Is your hydrometer calibrated? WY 3724 is notorious for rapid onset of fermentation then tapering off. It benefits from increased temps as it goes. With that being said 1.064 is too high for this yeast to taper off.

When you racked it too soon (if your hydro is calibrated which I suspect its not) you forced a stalled fermentation. From my understanding once a fermentation stalls it takes a ver large slurry of active yeast to get it going. I prob would have left it in the secondary after you repitched and kept it warm since the bulk of fermentation was done which would have limited off flavors caused by high ferm temps.

I don’t see anything in the recipe that would result in a higher FG. What was your mash temp and is that thermometer calibrated?

Hi Josh,

Thanks much for the thoughts. It’s still in the secondary now, puttering along. I’m going to keep the temp up and keep checking the SG until it looks reasonable. I have a stir plate and flask, I could always whip up a huge starter and see if I can get it to kick. I’m not familiar with stalled fermentation, this is keg #70 and I haven’t run into it yet.

Hydrometer is right off the store shelf, so not calibrated. Thermometer is.

I used a traditional multi-step mash schedule:

15m @ 137F, 35m @ 145F, 25m @ 165F, 5m @ 172F

Sparge was at 175F for 40 min.

  • Gregg

For the record, I made a starter with DANSTAR Belle Saison, wrapped a heating pad around the carboy and got it up to 70F, and the thing took off and ended up coming out very nicely. I’m about to order the ingredients to make it again.

The Belle Saison yeast works wonderfully. No starter required, either. However, for any saison, a good 4-week fermentation time may be required – don’t try to rush it because it takes time for the yeast to finish the job.

Good point Dave, it continued to ferment for another solid two weeks. I was amazed at how long it carried on. I think it got down to 1.007 by the end.

Lesson to be learned here: don’t rack to secondary until you’ve reached the desired FG. :cheers: