Attenuation Question - 1272

I am on day 9 of fermenting a 1055 OG APA with Wyeast 1272, American Ale II. I pitched a 1 liter starter at 66F. The temp rose to 70F in 24 hours where it has held since.* My yeast fermented vigorously for a few days and then flocculated, by about day 5, I'd say.

(*There was an episode yesterday--day 8 of fermentation--where the carboy rose to 74F for about 6 hours because the room got too hot. I moved it to another room, and it returned to 70.)

Back to my story. This morning I took a gravity reading, expecting to be at FG, but I was about .005 high. I'm trying to understand why.

Here's what the Wyeast web site says about 1272:

With many of the best qualities that brewers look for when brewing American styles of beer, this strain’s performance is consistent and it makes great beer. This versatile strain is a very good choice for a “House” strain. Expect a soft, clean profile with hints of nut, and a slightly tart finish. Ferment at warmer temperatures to accentuate hop character with an increased fruitiness. Or, ferment cool for a clean, light citrus character. It attenuates well and is reliably flocculent, producing bright beer without filtration.

Origin:
Flocculation: Medium-High
Attenuation: 72-76%
Temperature Range: 60-72F, 15-22C
Alcohol Tolerance: 10% ABV

And in their brochure:

Expect good attenuation, but this will vary with grist makeup, mashing protocol, or other wort characteristics.


With an 1055 OG, 72-76% attenuation would be 1013 - 1015. This morning I'm at ~1020. My first thought was this could be fixed by a little yeast rousing, a little heat, and a whole lot of patience. I can do all that.

My second thought was that I might have already fully attenuated, based on my grist makeup and mashing protocol. My APA was mashed at 154 for one hour, and the grain bill contains .25 lbs CaraPils/Dextrin Malt, which is 5% for a 2.5 gallon batch. I purposefully chose this mash temp and grain addition to provide body and head retention. The problem is that since this is my first all grain batch, I don't understand whether, how, or the extent to which these choices might have limited the fermentability of my wort.

My specific question is this: is it possible that full attenuation in this instance could be 1020? Is it possible to get full attenuation outside of the 72-76% range cited by Wyeast?

Incidentally, the hydro sample was delicious. I don't know if I'm tasting the Munich malt (see below for my recipe) or the slight nutty flavor that Wyeast promised, but right now this APA has a wonderful hazelnut flavor. It's beguiling, really. I've been thinking about it all day.

If this beer doesn't hit 1015 after another two weeks I won't mind a bit. I just don't want to bottle when the yeast might have more work to do--I'm afraid of bottle bombs. I also see this as an opportunity to get to know the yeast better.

Any thoughts from yeast experts and experienced brewers would be welcome.


Here's the beer:

American Pale Ale

2.5 Gallon batch (3.8 gallon pre-boil, 3 gallon post-boil)
OG 1.055
~27 IBU
~8 SRM

4lb 2-Row Malt
0.75lb Munich Malt (10 L)
0.25lb CaraPils
(All crushed for BIAB)

Mash at 154 F

.25 oz loose Simcoe - FWH
.25 Simcoe - 10 minutes
.25 Simcoe - 1 minute

Boil 60 minutes

Ferment at ~68 F with Wyeast 1272, American Ale II

tonyolympia said:

how much exactly do grain bill and mashing protocol influence the final fermentability of wort?

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Probably more than you think. Mash & fermentation conditions are key. If I were in your shoes I'd rouse & maybe raise ferment temp. a tad.

How well the yeast was handled and it's viability also matters.

Soperbrew said:

How well the yeast was handled and it's viability also matters.

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The yeast was a pretty recent vintage. Not sure of the date, but something like 10-14 days prior to purchase.

I think that I handled the yeast carefully. I was certainly careful in making my starter. However, I did have a Three Stooges moment right before pitching where I stupidly shook the starter (rather than swirling) and some of it sprayed on my face. (I don't think I lost too much of it.)

tonyolympia said:

I stupidly shook the starter (rather than swirling) and some of it sprayed on my face.

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I think that's called a yeastkake. Looks like you're ok.

My pale with 5% crystal, 154 mash temp went from 1.046 to 1.012 for about 72% so the yeast isn't a super strong worker but it's not a slouch either. Try warming it and rousing, if it doesn't do anything bottle it on up.

I used 1272 once in a pale. 148 mash temp, 80% Golden Promise, 17% combined caramel malts and 3% carapils. 1.053 - 1.0105, ~80% ADF. I pitched around .8 million cells/mL/ºP and O2'd to about 12ppm (3 Lpm for 27 seconds in 5.5 gallons of wort).
Pitched at 65F and held for 2 days then let warm to 70F until finished.
After 4 days it was at 1.017 and it took another 11 days to hit 1.0105. There was very little CO2 being produced from day 5 to day 15 but there was still krausen.

SwampassJ said:

Try warming it and rousing, if it doesn't do anything bottle it on up.

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I warmed and roused last night, so we'll see.

Is it really OK to bottle a beer that you expected to reach 1015, but is stuck at 1020? I won't have to worry about gushers or bombs?

I'm getting the hang of brewing pretty well, mastering the techniques and concepts, but for some reason I have a block with this one.

dstar26t said:

I used 1272 once in a pale. 148 mash temp, 80% Golden Promise, 17% combined caramel malts and 3% carapils. 1.053 - 1.0105, ~80% ADF. I pitched around .8 million cells/mL/ºP and O2'd to about 12ppm (3 Lpm for 27 seconds in 5.5 gallons of wort).
Pitched at 65F and held for 2 days then let warm to 70F until finished.
After 4 days it was at 1.017 and it took another 11 days to hit 1.0105. There was very little CO2 being produced from day 5 to day 15 but there was still krausen.

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Thanks, dstar. I pitched more yeast than you and fermented warmer, but my mash temp was 6 degrees higher. I had slightly more CaraPils than you. I don't know how Munich compares to crystal malts in terms of fermentability. In any case I'll wait it out for another week to see if gravity drops at all.

I almost wish I hadn't roused and warmed the yeast last night. It looked so pathetic all swirled up and greenish-gray, when it had been so tight and prettily stratified at the bottom of the carboy.

Wait one more week then test. If it's done at 1.020 it's done, not too high like 1.030 or 1.040 where you wouldn't have a drinkable beer.

*deleted*

Carapils - evil evil malt that one is. Kidding of course, but I often fail to see the need most of the time with high enough mash temps, and I definitely don't use it if any crystal malts are in the grist all ready.

And if anything, I usually find myself infinetly happier when a beer attenuated better than expected, rather than the other way around. My .02 anyway.

Soperbrew said:

I think that's called a yeastkake. Looks like you're ok.

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Ate you certain you aerated properly? I've only ever had two beers fail to attenuate and 1 of them was because I completely forgot to aerate it...doh.

I'm not sure what I did wrong... I started this thread about a year ago.

These days I tend to get much higher attenuation. Two batches in a row, one fermented with Denny's Favorite 50 and the other with Wyeast 1968, both finished at 1.009. It sort of blew my mind. I'm starting to feel more comfortable mashing high.

tonyolympia said:

I'm not sure what I did wrong... I started this thread about a year ago.

These days I tend to get much higher attenuation. Two batches in a row, one fermented with Denny's Favorite 50 and the other with Wyeast 1968, both finished at 1.009. It sort of blew my mind. I'm starting to feel more comfortable mashing high.

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Haha, I saw it in current threads and never even bothered to see the original post date! I have an Irish Dry Stout from a few months back that locked up tight at 1.020. I don't know why. I'm guessing that the 25% Flaked adjuncts gave me too many long chain sugars...but I'm still bothered by that one. If anything, I usually get my beers a touch more attenuated than I had hoped. Brewing is a silly game.