Stuck fermentation, guess not, attenuation questions...

So... Here's the deal. Last Sunday I brewed a Holiday Spiced Ale extract recipe. Basic recipe as follows:

5lb. Light LME
2lb. Amber LME
Steeped 1/2lb. Crystal Grains
1lb. Honey
2oz. Hops
Added: orange zest, cinamon, ginger for 10 mins of boil
Added: aroma hops last 2 mins of boil
Pitched: Safale US-56 American Ale Yeast into wort at 70 degrees, aerated 5-10 minutes VIGOROUS. There was 2"+ of air bubbles on top, so I believe it was aerated well?
OG ended up being 1.050 before pitching yeast

Anyway, 24 hours later I had bubbling through the airlock at 6p/m, 48 hours later I had 20 bubbles p/m through the airlock and this lasted two days.

Now, I don't know if 20 bubbles p/m is "vigorous" fermentation, but I had 0 bubbles coming through the airlock today when I returned from work and the temp dropped from the normal 70 to 64-66ish with the colder weather today. I watched for literally 10 minutes, not one bubble. I heated it up with the brewbelt, still nothing.

I figured after 5 days it could be done fermenting and I was worried about it being stuck, so I removed the airlock, then removed the lid to grab a sample. There was a small krausen remaining/yeast floating on top. I took a sanitized cup and dipped through and got a sample. Replaced the lid ASAP. Sanitized the bottom of the airlock and replaced.

Dumped the sample in my hydrometer sleeve and measured a gravity of 1.016. First question was, what attenuation am I at. I can't recall how to calculate this and couldn't find a calc in Papazians "bible". Anyway, from 1.050 down to 1.016 seems pretty respectable, but am I done?! Should I rack to secondary soon?

Well, maybe my question was answered? I came downstairs after testing the sample and now my airlock is bubbling at about 10 bubbles per minute!!! Did I just have a bad seal before? Hard to believe considering it bubbled fine for 4-5 days.

Could the little stir from the measuring cup have restarted the yeast? Or did the CO2 on top of the batch just get warm enough from removing the lid that it has started to perk through the lock a bit? Am I Ok removing and replacing the lid like this? Or should I just rack to secondary now that I'm down to 1.016?

Comments, questions, thoughts?

Oh, beer smelled good too!

If it's bubbling that fast again, just let it go. You probably roused the yeast a bit. Don't worry about racking to the secondary - you can let it go for another 3 weeks without hurting a thing. When the bubbling stops (again), wait another day or two, then rack. Sounds like everything's fine. Even if it stops at 1.016, it'd probably be a good beer.

Cool; I just hope now I didn't contaminate anything by opening it up; I sanitized the airlock again, but not the lid itself. It was off for literally 1 minute...

Can anyone comment on how to calculate attenuation? I'd like to know what % I'm at and where I'm heading (anywhere between 70-80% is good correct?). My yeast pack did not mention an attenuation, btw.

Ok think I found it:

(OG-FG)/(1-OG)

So, (1.050 - 1.016)/(1 - 1.050) = .034/.050 = 68% Attenuation

Is this correct?

If so, I guess I do still have a few points to drop off... Should be ready to rack by the end of the weekend hopefully.

68% is pretty respectable for attenuation. The numbers reported by the yeast labs are almost always optimistic and measured in ideal conditions. Sounds like you're probably going to see even better than that. Good beer is only a few weeks away!

Yea, pretty good thus far... I've searched yahoo and came up with a few other brew-sites reviewing the Safale US-56 yeast. Seems it has good attenuation. I've found 3 cases in maybe 10 mins where people have claimed to gotten 73-85% attenuation out of this yeast. (Yes, 85%; he claims to have went from 1.082 to 1.012!?).

Oh well, I'll wait until Sunday, hopefully bubbling will subside and I can rack to a secondary.

Ok; the confusion is back...

Went to bed with it bubbling 10 per minute; woke up and not 1 bubble in 5 mins. Still sitting at 70 degrees, etc. How does it just die off so quickly?!

Or did removing the top just heat the C02 in there enough that it started rising more when I replaced the top?

A final gravity of 1.016 is fine. Even if you managed to get it to 1.012, you're only talking about a difference of 0.5% ABV. Most of my beers end up in the 1.016 - 1.020 range.

On the other hand, it might be completely screwed, in which case you can just drop it off at my place and I'll take care of it for you.

Haha. Thanks man. I'm going to wait until Sunday and rack this to a secondary.

What is the protocol for racking to secondary if the krausen and yeast on top hasn't fallen? Obviously I won't know this until I remove the lid again as its in an ale pail... What if I pop it and there is still stuff on top? Replace lid and do not rack?

I sincerely doubt you'll see any krausen if the fermentation has dropped to the level you describe. I'm not sure what to do if there's still some there! I'd probably leave it alone.

The reason I ask is b/c last night there was still some remaining. It probably was only 1/4" or so, but it was still there...

SilkkyBrew said:

The reason I ask is b/c last night there was still some remaining. It probably was only 1/4" or so, but it was still there...

Click to expand...

D'oh! Looks like I'm unqualified to answer this one.

Pull the airlock off an take a look, but 95% chance the krausen has fallen. 1/4 inch isn't enough to worry about.

Some times when honey is added, the initial ferment is fast (fructose & glucose are easy to process), then it stops for a while and restarts as the yeast adapt to the more complex malt sugars.

david_42 said:

Some times when honey is added, the initial ferment is fast (fructose & glucose are easy to process), then it stops for a while and restarts as the yeast adapt to the more complex malt sugars.

Click to expand...

I wasn't aware of this. In any case I only added 1lb. Honey and 7lb. malt extract. I doubt if only the honey was fermented at this point that my gravity would be down to 1.016?

I'm still a beginner myself, but I found that when using a bucket primary, the airlock activity is only an indicator of vigorous fermentation. That is, the pressure is so great that CO2 is escaping at both the bucket lid and through the airlock. Once the ferment levels off a bit, it's likely that the offgassing is finding enough escape through only the leaks in the lid.

Beside the impatience that I know you're feeling right now, there's really no hurry to rack it.