beer finished high

[Hoochin'Fool]

Had a beer that finished "too high" for a second time in a row now, and I don't know what I did wrong...

It's a stout, OG is 1063, and FG is supposed to be 1.011 -- but after 6 weeks in the fermenter, it is still stuck at 1.020, and hasn't budged one bit in over a week!

I do a full volume BIAB, with water tuned to London Profile, and phosphoric acid added to reach a software-predicted pH of 5.5
I'm very confident that my ThermaPen is reading my mash temps correctly (152F, dropping down to 149F after 60 mins).
I know my ferment temperature is reasonable for the yeast I'm using (64F to 70F in my basement this time of year, and the yeast is US-05).

Think it's safe to bottle?

 

[VikeMan]

It's a stout, OG is 1063, and FG is supposed to be 1.011 -- but after 6 weeks in the fermenter, it is still stuck at 1.020, and hasn't budged one bit in over a week!

Where is the expectation of 1.011 coming from? Most brewing software does not adjust attenuation based on the grain bill, and stouts tend to use significant amounts of grains with fairly low fermentability.

You provided the OG, mash temp, mash length, and yeast strain. If you can provide the grain bill, I can tell you what BrewCipher would predict for FG. I strongly suspect it's going to be something higher than 1.011.

 

[Hoochin'Fool]

Thanks VikeMan! 1.011 is coming from BrewersFriend. The first 2 times I made it, it came out on the nose: 1065 -> 1011, and now the last 2 times, I must be doing something wrong...

[3 gallon into fermenter]
5 lb Briess 2-row
8 oz Briess Munich 10L
8 oz Turbinado
8 oz Fawcett Dark Crystal 85L
4 oz Weyermann Chocolate Rye 240L
4 oz Fawcett Pale Chocolate 230L
2 oz Briess Chocolate 350L
2 oz Briess Roasted Barley 300L
2 oz Briess Midnight Wheat 550L

And before anyone critiques the overly-complicated dark grains, hey it's tasty! Very chocolatey!

Also, the grain was purchased at either RiteBrew or NorthernBrewer within the last 4 months, and milled by myself the morning of the brewing.

 

[VikeMan]

For your grain bill, OG, mash temp and length, and yeast strain, BrewCipher predicts an FG of 1.014

But I would say that if the beer has been stable at 1.020 for over a week, it's probably safe to bottle.

 

[BrewnWKopperKat]

Had a beer that finished "too high" for a second time in a row now, and I don't know what I did wrong...

For the last two beers that finished high, was it the same recipe or two different recipes?

Also, was your source water a blend of tap and RO/distilled? If so, could there be a seasonal cycle to some aspects of the tap water?

 

[Hoochin'Fool]

For the last two beers that finished high, was it the same recipe or two different recipes?

Same recipe (well, I played around a little with hops, but all hops were in boil or flameout for all versions).

Also, was your source water a blend of tap and RO/distilled? If so, could there be a seasonal cycle to some aspects of the tap water?

Actually, it was all tap water (my water's already pretty close to "London Profile", I just need a gram of CaCl, a gram of Gypsum, and a half-gram of sea salt. Oh, and a freakin' ounce of phosphoric 10% acid, to get my mash pH under 5.6 -- so yeah, if my tap water changed dramatically from winter, maybe that explains something? Doesn't taste any different, tho my spouse says she notices more chlorine lately (I do treat with K metabisulfite).

 

[Bobby_M]

Despite confidence that the expensive thermapen is correct, did you confirm by testing an icewater slurry and water at boiling to see if there has been some calibration drift? 3-4F of higher mashing temps would do this.

 

[Hoochin'Fool]

Despite confidence that the expensive thermapen is correct, did you confirm by testing an icewater slurry and water at boiling to see if there has been some calibration drift? 3-4F of higher mashing temps would do this.

It's been a while, so I just tested it now.

Ice bath: 32F
While waiting for my water to boil, tried it in my mouth, under the tongue... 95F, a brief moment at 96F, then nothing but 95F
Boiling water: 212F... actually, water boils at 211F here, and the pen USED to say my boils were always at 211. Tho it's been a long time since I bothered to take a temp reading on the boil!

So ice bath and boil are reasonable enough, but there's no way in hell my body temp is 95!

Google tells me 40% vodka should boil at 173F, but none in the house right now, seems like that'd be a reasonable data point to check. Something to check this weekend.

 

[doug293cz]

Google tells me 40% vodka should boil at 173F, but none in the house right now, seems like that'd be a reasonable data point to check.

The phase diagram I have says 40% ABV in water (vodka) boils at 84°C, or 183°F. 173° (78.3°C) is the boiling point of pure ethanol or the water ethanol azeotrope (78.4°C and 78.1°C.)

Brew on

 

[Hoochin'Fool]

The phase diagram I have says 40% ABV in water (vodka) boils at 84°C, or 183°F.

Brew on

Are you suggesting that Google search would serve me up some inaccurate results?!? Thanks, upon closer examination, while the question was about 40% ethanol, the answer was for 95+% ethanol, and I just took a quick glance!

 

[Hoochin'Fool]

Man, a guy can't even boil a couple of ounces of vodka on the stovetop in peace, without some busy-body popping in and loudly asking "WHAT THE BLEEP ARE YOU BOILING VODKA FOR?!?" ...

Anyways, the pen says ice bath is 32F, tap water boils at 212F (it should read 211F at 930 feet elevation), and Phillips 80 proof vodka boils at 182F. If I press the pen uncomfortably into the underside of my tongue, it flutters between 97 and 98.

So I don't think my mash temp should have been over 152 for more than about 5 minutes, whilst I'm stirring the grain in. Going to re-brew the recipe on Friday, and pay extra attention everything (grain weight, water volume, temps, etc). Would doing an iodine test be of any benefit?