My stout stopped at 1.030, what should I do?

[Cranapple]

For my second batch I decided to make the "Toad Spit Stout" from Papazian. Something seemed a little off right from the beginning, because I followed the recipe exactly and the OG was 1.072, way over the 1.054 recipe target.

I pitched 2 packets of safbrew s-33, at 70-75F, however I may still have underpitched since I had stored them in the freezer, so that may have killed a lot of the yeast. Ambient temp for fermentation was 65F, but they were on the basement floor, and I think that dropped the temp by more than 5 degrees.

The airlock started bubbling extremely fast, like within a few hours, but stopped abruptly after about 30 hours. I've lurked long enough to read Revvy's take on airlocks as fermentation gauges, so I just let it sit for 2 weeks. It was at 1.030 then, and the same a week later.

If I'm doing my math right, that's a 47% real attenuation. Am I done? Does the high OG mean that I got too many unfermentables out of my grains?

So what should I do? I'm in the process of warming the fermenter up to 75F, but I'm trying to decide whether to repitch or just try to gently rouse with a sanitized spoon.

 

[Pappers_]

If you pitched two packets of s-33, I don't think i'd repitch. Your idea of warming it and rousing is probably the best.

We can't really diagnose what went wrong without more details. But it sounds like you're not sure what exactly happened - a twenty point difference in original gravity means something happened. If you give us some details, we might be able to help.

 

[Beer_Guy]

Check your hydrometer.

The drop of 0.044 would give the 1.054 a nice 1.010.

How does it taste?

 

[SwampassJ]

Check your hydrometer in 60 degree water, should be at 1.000. If you did an extract you should be right on the money, very difficult to miss gravity with pre measured malt sugars with the right water volume.

 

[Cranapple]

Thanks for the tips guys, I appreciate it.

SwampassJ, The hydrometer checks out perfectly, that's the first thing I checked. I thought the same thing, how did I mess up an extract OG? This is one of my first batches that used real grains though, so I'm not sure how much the "mash" of the grains can affect the OG.

FYI: After bringing it up to 75F and rousing the yeast, my airlock is bubbling again. I guess now I'm just looking for answers about how much variability you can get in your OG when using specialty grains. Also, how long do I need to keep the fermenter at 75? Can I bring it back down to 65-68 now, or will that shock the yeast into settling out again?

To avoid a tl;dr, I'm putting the recipe at the end in case someone wants to critique my method.

Here's the recipe as I did it (some small adjustments to Papazian's recipe):

3.3 lbs. Munton's Dark LME
4 lbs Munton's Dark DME
.75 lbs crystal malt (60L)
.33 lbs roasted barley
.33 lbs black patent
2 oz pellet Northern brewer (60 min)
1 oz pellet Fuggles (5 min boil)
8 tsp gypsum
2 packets Safbrew S-33 yeast (11g ea)

I put the grains in a bag and the bag into my boil pot, which I filled with room temperature water. I turned on the heat and brought the whole mixture just up to boiling, then removed the grains so as not to remove too many tannins. That took approx 30 mins.

I added 3lbs of the DME and boiled my bittering hops for 55 mins, then added my late addition for 5 more mins. I added the LME and remaining 1lb DME at flameout. I cooled to 70F and pitched the yeast.

 

[Cranapple]

In case anyone else has an issue with this recipe in the future, I found a version of it on beertools.com which lists the OG at 1.068.

They used 0.7lb more malt extract and a couple ounces less grain, but my guess is that the OG should be pretty similar. It really isn't far from my 1.072 value, and I might have been an ounce or two heavy on the grains.

At this point I'm thinking that my OG was fine, but my pitching/aeration/fermentation temperature were the issue with the stuck fermentation. Any comments/corrections?

 

[SwampassJ]

Check it again in a week and see if it's dropped any, if not consider making another starter and or repitching some dry yeast to try and drop it some more.

I can't talk from experience because I completely skipped Extract and went all grain but I think someone mentioned in another stuck thread that using all dark extracts can yield a higher FG or if the extracts are older.

 

[rweird]

I had the same problem with my stout. I used dark extract too. I tried to warm the beer and rousing the yeast. nothing. repitched another 1L starter. nothing. I ended up adding 1lb of corn sugar to raise the abv and to thin the mouthfeel a little. mine ended at 1.026 Which gave me ~70% attentuation which was at the lower end of my yeasts range. better than the60%? it was. in short it took some simple sugars to get my yeast going again.

 

[Toga]

Now that you have warmed it up and it sounds like you have woken the yeasties up keep it at around 75 degrees. I have found 75 degrees to be the sweet spot for S-33.