Crazy Attenuation.....is This Bad?

[bignath]

Hi brewers, find myself in a weird situation that i don't understand...

Have recently brewed my "generic aussie fake lager" recipe, no chilled to cube, and fermentation started 1st October. Walked away from it, came back today to measure gravity, and my refractometer is giving me 4.6Brix. It started at 11.0 before i pitched the yeast. In gravity, that relates to corrected readings of 1.044 dropping to 1.002.

Yes i have checked and double checked my refractometer for calibration accuracy - it's spot on.
No there isn't any hint of an infection. Tastes like it should (albeit a tad more bitter due to lower gravity/higher attenuation.) But otherwise it tastes like i expect it to. I have brewed this often, so i know the recipe well.

It is:

20lt batch

3.6kg BB Pale
.2 Carapils
.2 Cane/Table/White Sugar

POR 10% 22g @ 60mins

Whirfloc @ 10mins

US05 @ 18deg.

I am wondering if the high attenuation (95.5%) is a "bad" thing, or somethig to worry about? It won't quite be the same as the other times i make this i know, but is it something to be concerned about? Typically i get a touch over 82% attenuation, so this is a big jump.....

As a side note (and i can't believe i'm asking this.....) We leave in the morning for Adelaide and we will be gone for a week. Getting back next thursday. I have a poker night hosting at my house on next Saturday (sat week) and this was going into a keg for the night.

Assuming it is done (how much further can it go below 1.002) would you throw it in the fridge to condition? If it's safe to do so, i will, as it means when i get back from Adelaide, i won't have to worry about conditioning, carbing and serving in time for the poker night. If i can get it in the fridge in the morning, all will be sweet.

I am concerned that it's only been 6 days, and the attenuation is showing she's done and dusted, way below where i expected it to finish (1.008)

I find myself in strange territory here, so thought i'd put it too you'se brewers..

Cheers,

Nathan

 

[Lord Raja Goomba I]

Bizarre (and I don't mean a market in Istanbul).

I've had notto do it down to 1.002, but not us-05.

Figuring you've either mashed a very sugar-y wort, your US-05 has been switched with notto, or it's a possible infection.

As for chucking in the fridge to condition - go for it. I do it all the time, and it tends to mean clearer beers without the farting around of gelatin, finings or any other junk I simply couldn't be bothered doing.

Goomba

 

[mxd]

refractometer aren't usable for fermenting beer, you need to put your SG and current G into a formulae (I use the beer smith tool) to convert it

unless of course you have done the conversion then ignore me.

But I can't see the us05 doing 97%

 

[manticle]

@mxd: Yes but normally it's the other way (reading way too high) and he did say 'corrected' reading.

@Big Nath: Have you tried with a hydrometer just to be sure?

 

[bignath]

refractometer aren't usable for fermenting beer, you need to put your SG and current G into a formulae (I use the beer smith tool) to convert it

Refractometers work just fine for fermenting beer.

As per my post above, the readings i'm getting have already been converted.

Walked away from it, came back today to measure gravity, and my refractometer is giving me 4.6Brix. It started at 11.0 before i pitched the yeast. In gravity, that relates to corrected readings of 1.044 dropping to 1.002.

 

[bignath]

Don't own a hyrdometer anymore Manticle.....completely switched over to my refractometer a year or so ago once i got used to doing conversions and all that stuff. Gave my hydro to a brewing mate to get him started.

Don't think i can catch up with him tonight to borrow it back either. Buggar....

Is there any "downside" to having higher than normal attenuation? Apart from the possible presence of an infection? Or lack of consistency between batches...

The first thing i thought of when i converted the readings (and this was before i tasted it) was, ****, it's gotta be infected, but all seems good. Normal looking krausen that seems like it might start dropping tomorrow, normal taste (apart from being a little more present with the hop profile - as you'd expect).

It's got me buggered.

It's actually also a double batch of the recipe above and both fermenters are showing the exact same readings...Both look and taste normal.

 

[jyo]

Nath, I had this problem for a couple of beers with US05. My 1050 APA got right down to nearly 1006 So, yes, very dry...
The good man Cocko suggested to check the thermometer I was mashing with in a kettle of boiling water. Turns out my thermometer was 2 degrees out. I was actually mashing at 64'...The last couple of brews I have compensated for this and attenuation is back to normal.
Worth a check, mate.
Cheers.

 

[manticle]

Only problem if it isn't infection is the obvious one - beer will be a different balance to expected. Might be super refreshing and beer can still have a dry finish with sweetness or body (in my experience).

The only issue I see with cold conditioning now is the lack of time spent on the yeast cake at ferment temps to clean up diacetyl, acetaldehyde and whatnot that may or may not be present.

 

[bradsbrew]

Nath, I had this problem for a couple of beers with US05. My 1050 APA got right down to nearly 1006 So, yes, very dry...
The good man Cocko suggested to check the thermometer I was mashing with in a kettle of boiling water. Turns out my thermometer was 2 degrees out. I was actually mashing at 64'...The last couple of brews I have compensated for this and attenuation is back to normal.
Worth a check, mate.
Cheers.

Thats exactly what I was thinking as I was reading through the replies. Is the mash temp lower than it should be?

Cheers

 

[WarmBeer]

Is there any "downside" to having higher than normal attenuation? Apart from the possible presence of an infection? Or lack of consistency between batches...

How does it taste?

That's what really matter.

 

[bignath]

Hmmmm, to be honest i haven't checked my mash thermo (mashmaster 4" dial) for a while. Will check it out.

My mash measured 66 which is what i was aiming for, and what i always brew this recipe at. Will check that this is accurate though.

 

[bignath]

How does it taste?

That's what really matter.

Tastes good. Tastes normal, just a little more pronouned on the hop side of things. As it's a generic megaswill recipe, it's still not overly hoppy or bitter by any stretch, but it is a little more than bog standard recipe.

 

[manticle]

Then look forward to drinking it when you return and check all your equipment before your next mash

 

[Tim]

Hmmmm, to be honest i haven't checked my mash thermo (mashmaster 4" dial) for a while. Will check it out.

My mash measured 66 which is what i was aiming for, and what i always brew this recipe at. Will check that this is accurate though.

Regardless of what temp the mash was out, you won't get 97% attenuation out of US05. Its most likely that you have either made a mistake measuring your FG (unlikely by the sounds of it) or you have picked up a wild yeast. Luckily the beer tastes ok.

 

[mckenry]

Regardless of what temp the mash was out, you won't get 97% attenuation out of US05. Its most likely that you have either made a mistake measuring your FG (unlikely by the sounds of it) or you have picked up a wild yeast. Luckily the beer tastes ok.

Agreed.
Also, refracts arent good for measuring finished beer unless your corrections are this;

from Wolfy

Open BS, then Refractometer tools.
Enter your original refractometer reading and select 'Unfermented wort gravity'
Then it should spit out exactly the same value your hydrometer measured OG.

Now enter your final refractomer reading, select 'Finished beer ABV/OG' and enter your OG value.
Now the result should be the same as you measured for your final gravity with the hydrometer.

 

[drsmurto]

If it tastes normal then i would be pointing my finger at a dodgy calculation/refract readings. How many data points did you use to calibrate your refractometer?

1.002 would be very dry and you should be able to taste the difference.

EDIT - Beersmith allows you to calibrate your refractometer but only uses 1 data point which is woefully inadequate. You should be using at least 3 data points for a calibration.