Oatmeal Stout Stuck at 1.027

[avachon37]

Hi everyone, this is my first post here but I have been lurking in the background for awhile.

I brewed an all grain oatmeal stout (recipe below) back on Jan. 31st which went into the carboy at 1.054. I used a packet of safale US-04 in a 1 liter starter which had 24 hours to get going before it was decanted and pitched.

The fermentation started off great, I had a solid two days of intense action in the carboy and then everything just settled out. I decided not to take any action right away and let the beer do its thing for about 2.5 weeks.

I checked the beer on 2/17 and got a S.G. of 1.027 . Target per the recipe I used was 1.014.

From information I gathered around here I tried swirling the carboy around to rouse all the yeast off the bottom 2-3 times a day for another week.

On 2/23 I rechecked the gravity and it was still exactly 1.027...

The next day I took a trip to my local homebrew store and was told to re-hydrate another packet of US-04 and pitch it with some powdered yeast nutrient. Which I did that night.

After three days of nothing visibly happening in the carboy I decided to check the SG again today and its still stuck at 1.027.

Anybody out there have more suggestions?

Thanks for the help.


Recipe:

8 lbs US 2-Row
1 lb Caramel/Crystal 60
1 lb Chocolate Malt
0.75 lbs Roaster Barley
1 lb Flaked Oats

2 oz Willamette Hops 5.1%
1 oz Fuggles Hops 4.0%

 

[Yooper]

Is your hydrometer reading water at exactly 1.000? (not a refractometer reading, a hydrometer). If it's a refractometer reading, run and get a hydrometer reading.

What was the mash temperature? Maybe there are a lot of unfermentables if the mash temperature was too high.

 

[avachon37]

The mash temperature was 150°F (slightly lower than my target of 154).

I have been using a refractometer to measure SG. I've checked its calibration multiple times and it is reading 1.000 with pure water at room temperature.

I'll grab a larger sample and check it with the hydrometer.

 

[MilkStout]

It is best to measure the specific gravity after fermentation as the alcohol makes the reading inaccurate. There are conversation calculators that you can use to convert a refractometer reading more accurate in the presence of alcohol. I am sure how much I trust them, but some do. If I use the one I have, I get a 1.011 reading.

 

[avachon37]

Well I'm never using a refractometer again...

Just pulled a sample out and checked it with a hydrometer and got 1.014 which is exactly where the recipe said it should be.

However, that means the OG reading I had was probably bad as well.

In the name of science I added some pure cane sugar to the beer sample I pulled out until I got to 1.054 on the refractometer (which was my OG reading before). Checking this with the hydrometer gave me 1.040.

Looks like I'm going to end up with a weak ass stout at around 3.5% ABV. Hopefully it tastes good enough to make up for it.

This also means I got terrible mash efficiency... I think its time for a beer:smack:

 

[HollywoodTK]

Well I'm never using a refractometer again...

Just pulled a sample out and checked it with a hydrometer and got 1.014 which is exactly where the recipe said it should be.

However, that means the OG reading I had was probably bad as well.

In the name of science I added some pure cane sugar to the beer sample I pulled out until I got to 1.054 on the refractometer (which was my OG reading before). Checking this with the hydrometer gave me 1.040.

Looks like I'm going to end up with a weak ass stout at around 3.5% ABV. Hopefully it tastes good enough to make up for it.

This also means I got terrible mash efficiency... I think its time for a beer:smack:

Refractometers are very useful and accurate for measuring SG of wort where no alcohol is present. Your initial reading is probably right if you properly used a calibrated refractometer.

Hydrometers are best for measuring SG of beer, when alcohol is present. Alcohol will refract light differently in solution and will skew the results of your refractometer. As others have said, there are correction calculations which can estimate the final SG of your beer given your refractometer reading. However a hydrometer will be more accurate for this measurement.

 

[Calder]

As others have said, refractometers work fine for OG measurements.

If you want to re-check your OG reading, you can use one of the refractometer calculators and input both of your FG readings (Hyd and refrac), and it will give you your OG.

 

[Yooper]

A refractometer is a great tool! It's perfect for measuring pre-boil gravity, and for taking an OG.

Since refractometers measure the reflex of light in a sugar solution, alcohol will skew that reading. After fermentation, if a refractometer is used, some conversion software can be used to adjust the reading. It's still not 100% accurate, but it can be helpful in many cases. Here is a good one: http://seanterrill.com/2012/01/06/refractometer-calculator/

For me, I just always use a hydrometer for post-fermentation readings. but others use that calculator and have good results with the conversion.

 

[avachon37]

Wow guys thanks for all the great information! I was unaware of these refractomter calculators which will be hugely helpful in future brews.

 

[jdauria]

I had the same issue with oatmeal stout I recently made for my club competition in March. OG 1.060, BeerSmith estimated 1.014 FG...finished at 1.028! As one of my club mates pointed out, 36% of my grain bill was oats, crystal and roasted malts...lots of unfermentables there. The question is why did BeerSmith not factor in those unfermentables?

The beer still tastes good though, with using wlp007 it finished dry and is not as sweet as I would expect for a 1.028 finish.

Here's what my grain bill was:
8 lbs Maris Otter (Crisp)
1 lbs 8.0 oz Oats, Flaked (Briess)
12.0 oz Chocolate (Briess)
12.0 oz Victory Malt (biscuit) (Briess)
8.0 oz Carafa Special III (Weyermann)
8.0 oz Caramel Malt - 80L 6-Row (Briess)
8.0 oz Roasted Barley (Crisp) (695.0 SRM)

 

[Juno_Malone]

I had the same issue with oatmeal stout I recently made for my club competition in March. OG 1.060, BeerSmith estimated 1.014 FG...finished at 1.028! As one of my club mates pointed out, 36% of my grain bill was oats, crystal and roasted malts...lots of unfermentables there. The question is why did BeerSmith not factor in those unfermentables?

The beer still tastes good though, with using wlp007 it finished dry and is not as sweet as I would expect for a 1.028 finish.

See previous replies - were you using a refractometer to measure your FG? If so, you need to plug it in to a calculator (along with OG) to get the actual FG of your beer.

 

[jdauria]

See previous replies - were you using a refractometer to measure your FG? If so, you need to plug it in to a calculator (along with OG) to get the actual FG of your beer.

Thanks, I am aware, do use refractomter, and I use the calculator in BeerSmith to get actual. Checked with hydro too to confirm my refractometer was not off, I definitely finished high. It's finally carbed, tastes good, but just a tad thin to my liking.

 

[avachon37]

Jdauria - Do you live in Weymouth MA? I'm in Quincy