S04 attenuation problems

[Tancred the Brewer]

I just brewed 3 extract beers using s04 yeast. The first was a Brown Ale. 1.052 OG finished at 1.020 for 60% apparent attenuation. The second was a chocolate milk stout. 1.051 OG finished at 1.022 for 56% attenuation. The third was a scotch ale using yeast harvested from the brown ale. 1.069 OG finished at 1.022 as well for a 67% attenuation. All beers were fermented in my basement and maintained a 64-68 degree temp throughout fermentation. S04 is supposed to have 72-82% attenuation. Any ideas why all these beers would be so low on the attenuation? The milk stout could partially be the lactose sugar that doesn't ferment. Can't really come up with a reason for the others except maybe temperature.

Any thoughts or advice appreciated.

 

[Dland]

Extracts do tend to finish higher than all grain, or similar to an all grain that is mashed at high temp. My experiance with S-04 is it attenuates pretty well. Your fermentaion temps are not likely the problem.

 

[day_trippr]

All three of those dark styles - if dark DME was used there's going to be a fermentability hit.
Check out this page with the makeup of Briess extracts, and take a look at the difference between, say, Pilsen Light and Traditional Dark...

http://www.brewingwithbriess.com/Products/Extracts.htm
Cheers!

 

[BrewnWKopperKat]

Any thoughts or advice appreciated.

Can you provide recipes?

 

[SteveHeff]

I can only offer what I've experienced with S04, although it may not add any real empirical information. When I first started brewing, S04 was my go to yeast due to its availability and general function in fermenting the kind of beers I enjoyed at the time. For my first 5-6 beers that I brewed with it, I produced OK beer but my attenuation was anywhere from 62-68%, much lower than expected.

After consulting with my LHBS dude and reading a few of the threads on this site, I began managing my temps and volumes better than in the previous batches. Brewing with the same yeast, I was hitting 73-75% with no changes to my recipes or fermentation temps/time. It's also worth mentioning that I began using yeast nutrient, as well.

I'm not going to assume that either one or the other is directly responsible, but by utilizing both methods I was able to increase the attenuation and make the beers that I really wanted to make. Since you are working with extract, I would suggest using yeast nutrient. How long are you fermenting the wort for? Are you oxygenating your wort, with oxygen (not just shaking a fermenter/carboy)? I do agree that seeing the recipes will be helpful in determining what the expected FG should be.

 

[BrewnWKopperKat]

if dark DME was used there's going to be a fermentability hit.

Where are you reading this?

 

[SouthForkBrew]

My experience with S-04 is that it starts fast, ferments like a beast, and then chugs FOREVER! That being said, I've never made a bad beer with it. When it seemingly looks like it's crapped out, its still working, just very slowly. We did a NEIPA with it earlier this fall and it did the same thing. Reached 4-5 points above target in 36 hours, then took another week to get those last few points. Beer turned out awesome, too.

 

[day_trippr]

Where are you reading this?

Did you look at the linked material?

 

[BrewnWKopperKat]

Did you look at the linked material?

I did. In the "product information" PDFs, I noticed that "Fermentability" percentages for Pilsen and Traditional Dark were 75%.

 

[day_trippr]

Hah! Do you believe that though?
I mean, if you were to do two mashes, with all else equal, using these two grain bills...

99% Pilsen Malt
1% Carapils® Malt

vs

54% Munich Malt 10L
30% Base Malt
13% Caramel Malt 60L
3% Black Malt

...do you really think they'd finish at the same gravity?
I sure as heck don't

Cheers!

 

[BrewnWKopperKat]

Why not measure the fermentibility of the DME/LME more directly?

 

[BrewnWKopperKat]

Can you provide recipes?

How many gallons brewed in 2020 #786. Kit instructions are on-line, but don't contain information about the specific brand of liquid extract.

 

[Tancred the Brewer]

How many gallons brewed in 2020 #786. Kit instructions are on-line, but don't contain information about the specific brand of liquid extract.

Thanks KopperKat. Work schedule didn't allow me to post an answer yet. Yes they are all kits from Northern Brewer. Caribous Brown, Chocolate Milk Stout and Winter Warmer.

 

[Tancred the Brewer]

My experience with S-04 is that it starts fast, ferments like a beast, and then chugs FOREVER! That being said, I've never made a bad beer with it. When it seemingly looks like it's crapped out, its still working, just very slowly. We did a NEIPA with it earlier this fall and it did the same thing. Reached 4-5 points above target in 36 hours, then took another week to get those last few points. Beer turned out awesome, too.

I allowed the Brown ale to ferment in primary for 2 weeks before transferring to a keg for secondary. The other two stayed in primary for 3 weeks before going into a secondary. Given what you posted I may find them improving some as they age. Will be transferring the stout to keg in another 9 days so I will see if there is any change in gravity again at that point.

 

[Tancred the Brewer]

Also, for those who asked. I did use yeast nutrient for all three. I don't have an oxygen tank but I shake vigorously in the fermenter, and have never had any issues in 15 years of brewing with just that. I guess it could be a lack of O2 but the stout was pumping away CO2 within about 4 hours of pitching so not sure that would be the problem.

 

[BrewnWKopperKat]

Maybe a Fast Ferment test (link) for the next batch?

Answers about yeast and fermentation has a Q&A on aerating the wort.

 

[SteveHeff]

Perhaps I missed this somewhere in the thread, and I know the viability of dried yeast, but how old were your packets? It sounds like you covered most of your issues outside of the yeast. Pitched a single pack per 5 gallons of wort? I grasping at straw, here. Good luck with the future brews, Tancred.

 

[BrewnWKopperKat]

... Brown Ale. 1.052 OG finished at 1.020
... chocolate milk stout. 1.051 OG finished at 1.022
... a scotch ale using yeast harvested from the brown ale. 1.069 OG finished at 1.022 ...

What did you use to measure FG?