Failed Yeast?

I brewed a batch of beer about a month ago.  Simple brew, I’ve made it before.  Starting gravity was 1.070, as expected.  But the fermentation (Safale US-05) was slow.  After 2 1/2 weeks I bottled it, but the FG of 1.020 was unexpectedly low.  I was a little concerned that I might end up overcarbonated.  But after two weeks in the bottle, the beer is completely flat.  Yes, I did remember to add a priming solution!  I’m thinking that the yeast was not viable.

Next thought is to unbottle everything, add fresh yeast and rebottle.  Any suggestions?

How much yeast did you use? That is pretty low for 05 but I suppose it could depend on your grist, mash, etc.

Two weeks at about 70 degrees F is an average time for carbonating an average beer. Colder temperatures will slow the process as will high gravity or low amounts of yeast remaining in the beer. Gove it more time and move to a warmer place if needed.

Recipe?  Are you using a refractometer, or a hydrometer?

Using a hydrometer, same one I’ve used for 23 years.  I did move several bottles to a warmer room in hopes of speeding up the process.  I’ve never had a batch show absolutely no carbonation after two weeks before.

I used one packet of Safale, but the batch was only three gallons.  This quantity has worked before.

Recipe-wise, it’s my simple Winter indoor extract batch.  6 lbs. pilsner malt extract, Citra and Cascade hops (1oz. each), boiled for one hour.  Cooled to 72 degrees, yeast added.  I made the exact same recipe two months ago and reached a 1.014 FG.  The beer was very good, approx. 7.4% ABV.

Back to all grain and liquid yeast starters now that it’s getting warmer!

It could be an extract problem.  Different extracts, especially from different manufacturers, will have different fermentability.  That’s probably the issue with FG.  As for lack of carbonation… might just need another week.  Or maybe there’s a problem with your capper?!  Mine busted after about 20 years and 100 batches.  They don’t last forever.

Thanks for the ideas!  I think my capper is good, but I’ll double check.  I did notice that the malt is very dark for a pilsner extract.  Same brand I’ve used in the past, but noticeably darker.

I bought enough of these same ingredients to make another identical batch.  Brewed it yesterday, and I’m finding that the fermentation is very weak and the color the same.  I’m ordering more ingredients for an all grain batch and including some extra liquid yeast.  I may make a starter and pitch that into this newer batch if fermentation remains slow.

All of this is making me thirsty!

I wanted to get back to those of you who offered solutions.  Here’s where I am now, happily with a positive solution.  It seems that when I lowered my basement temperature (where I store my brew), I slowed everything dramatically.  Only a 4-6 degree change, but it made a huge difference.  I moved several bottles into the room where my furnace is, and within 3 days I now have some carbonation.  My newer batch that started slowly has also become more active.  I’m sure I’ll end up with some taste differences as well, but that’s all part of the fun of homebrewing.

Thanks again!

I had that problem once many years ago with an extract porter.  My capper was relatively new and worked fine (the next batch carbonated perfectly).  The beer just never carbonated for some reason and I suspected the residual yeast in the beer may have been dead.  Glad that you got results by moving the bottles to a warmer environment…

Cheers!