fermentation "stuck"? Have tried everything

Hi,

I brewed a batch of American Brown Ale about a month ago, OG .055, estimated FG .018.

I started fermenting at about 68 degrees and left for a week. During that time the temp dropped and the yeast crashed out early.. when I got back, my gravity was .040 with no more activity. I warmed the batch back up and things progressed, to about .030 after another week. From there, it's been absolutely stuck.

I tried agitating, I tried pitching more yeast, I tried just waiting... it's been a month since brewday now. I'm entertaining the idea that I screwed something up (it was an AG BIAB) and the FG is actually going to be .030, but that's a BIG difference.

Anything else I can try here? I'm afraid of exploding bottles and having a really weak beer

-Ed

If you list the recipe, process and temps people ca chime in, sounds like too many crystal type malts and too high a mash temp off the cuff.

The only thing you can try is amylase enzyme to chew through it

duboman said:

If you list the recipe, process and temps people ca chime in, sounds like too many crystal type malts and too high a mash temp off the cuff.

The only thing you can try is amylase enzyme to chew through it

Click to expand...

Thanks. I've attached my beersmith report. Looks like my OG was really 1.048 which makes this situation even worse...

Please note that it is a small batch and only makes 2.5 gallons

Thanks!

View attachment recipe.bmp

View attachment steps.bmp

This is a long shot but if you are using a refractometer for your final reading and NOT correcting for the presence of alcohol then your final brix/gravity is inaccurate.

OG: 1.048, ~12.2% Brix
Observed reading: ~7.7% Brix, ~1.030
Corrected FG: 1.0166 which would be close to your expected FG of 1.015

(calculator: http://seanterrill.com/2012/01/06/refractometer-calculator/)

stpug said:

This is a long shot but if you are using a refractometer for your final reading and NOT correcting for the presence of alcohol then your final brix/gravity is inaccurate.

OG: 1.048, ~12.2% Brix
Observed reading: ~7.7% Brix, ~1.030
Corrected FG: 1.0166 which would be close to your expected FG of 1.015

(calculator: http://seanterrill.com/2012/01/06/refractometer-calculator/)

Click to expand...

+1
Good call!

First, a high mash temp means a higher FG. but it's not all that high.


Check it with a hydrometer and make sure the hydrometer is accurate. You'll probably want to be under 1.020 but higher would be acceptable with that mash temp.

Thanks for all the responses.

Yeah I did all of my readings with a trusted hydrometer. I did manage to keep the mash temp at 155 throughout - is that uncommonly high and potentially responsible for these "unfermentable" sugars? Also, I probably mashed longer than 45 min - upwards of 1hr 15 min. I was under the impression that longer mash would help with efficiency (my efficiency is seriously lacking with current setup)

How should I make the final decision on whether to bottle? If I do it now I'm looking at a seriously weak beer (1.048 - 1.030 = 1.8% abv )

I knew it was a long shot

I have not found 155F to be uncommonly high especially for a malt-forward beer containing no carapils (or other body/head enhancing additions). As an example, I recently did an ESB mashed at 157 for 60 minutes with a 10 minute mashout and it fermented to completion within 5 days or so (SG 1.058, FG 1.015).

A longer mash actually gives the enzymes more time to work on breaking down the sugars, thus making a more fermentable wort, which should yield a lower final gravity.

Based on the information you've provided, I have not come up with a reason why you would be stalled at 1.030 with the possible exception of "the yeast just crapped out due to temperature drop". If you're willing to throw more money at this batch then you could picked a vigorous liquid yeast strain, make a 1L starter, and pitch it at high krausen with starter-to-beer temperatures very close to each other (~70F for each). This should give the yeast the best chance of just going from eating the starter sugars right into eating the beer sugars, and if the temperatures match then there really should be no acclimation or lag phase.

I personally would not bottle that batch for several reasons: possible bottle bombs, high residual sugars, low alcohol. If I was in your situation and was unwilling to put more money into the batch I would either wait indefinitely for the batch to finish (1-6 months) with what's already in the ferementer; try to encourage it to finish up by pitching a starter at high krausen; or dump it if nothing ever worked.

Edit: I just had another idea about your hydrometer reading. Are you giving the hydrometer sample enough time to dissipate co2 and let sediment settle? It could be as simple as pouring your sample through a coffee filter and letting it sit for 12 hours on your counter prior to taking a reading. High levels of either of these will increase the gravity reading.

Thanks a ton for the detailed response. I haven't let it sit for THAT long, but I drew my sample off the top and sat it for ~20 min, didn't see any sediment. Not so sure about the CO2 dissipation, but I did have a taste of the wort and it's pretty sweet still. I'm going to go with the starter and see where I get. If that doesn't get me anywhere, I guess I'll just end up dumping it.