Another "stalled fermentation?" thread...

[thecolin]

Hi everyone, first time poster, long time lurker. I've got an IPA (canned extract from Blackrock) that's been sitting in primary for about three weeks. I started off with an OG of 1.050 and I now sitting at about 1.019. I've added amber malt instead of sugar, plus another 500g of chestnut honey. From looking at other recipes, it seems a little high to me, though I'm not certain, maybe it's time to bottle? With the addition of the honey, I thought it would go lower.

My house is heated to about 20c (68f) so it should be warm enough. When I first notice the higher than expected FG (1.020), I started to shake it every few days, and it dropped down a point, but nothing more for a while after. So should I repitch yeast? Or is my extract just too high in dextrins perhaps? Will a different strain of yeast consume more sugars? Or should I try and warm it up a bit?

Thanks for any info one might be able to provide.

 

[Revvy]

THere's nothing wrong with 1.019 actually.....It's below the dreaded "curse of the 1.020," that often happens with extract beers. It's almost expected these days that extract batches often finish at 1.020 (or 1.030 on occasion) and nothing will bring them lower. Back in my extract days I bottled many a batch that finished that high, the beers were fine. I've often wondered if it doesn't have something to do with the production of some nonfermentable sugars in the wort carmelization during the boil.

It's been 3 weeks, so I'd say you are probably done....I would give it another 2 days, take another grav reading, if it is the same, then you should be safe to bottle. It really isn't about the how high the fg is, as much as if it is finished fermenting yet. I've bottled at 1.030 with no issues before.

 

[thecolin]

Alright, thanks for the advice. From what I've seen, you seem to have an excellent philosophy when you brew, so I'll do just as you said. (as I said, first time poster, long time lurker)

 

[thecolin]

So it looks like my patience has paid off. A few days ago, full on fermentation suddenly kicked in pretty strong for a good 24 hour period. It was pretty out of the blue, given that there had been next to no activity for over two weeks before. I was worried there was some sort of infection that had suddenly taken hold, given the strength of the activity. But when I checked the gravity, it had dropped another 8 points, and no funny taste when I tried it (though obviously a bit lighter in body).

Does anyone have any insight into this sudden burst of activity? Is this normal? The ambient temperature and the temperature of the fermenter appeared to be identical to what they had been for the past three weeks. I had been shaking the fermenter a while before, but I had stopped by that point. I suppose that could be a contributing factor, since it seems to be the only variable since primary fermentation over the preceding three weeks. But I'm curious if there is another more technical explanation that somebody might provide to explain this. Is there possibly some sugar that eventually broke apart into something that the yeast could eat? Or did the yeast suddenly wake up for some other reason?

Since my last few batches (extract based) have stabilized at about 1.020, I want to understand the variables to I can get fuller fermentation in the future.