High Attenuation with US-05

[hoosier2137]

I'm relatively new to brewing but an apparent attenuation of 90%+ just seems wrong to me. I brewed a single hop centennial pale a few weeks ago with an OG of 1.045. That was pretty close to what I was shooting for. It fermented in primary at about 68F for 2 weeks and I bottled. I took my FG reading and it came out to 1.004. The bucket I'm using has been put through the paces so there's a chance for infection but I think I do a great job with sanitation and cleaning.

Grain bill:
8# 2 row
.5# Munich
.5# crystal 40L
.25# carapils

Mashed at 151F

Any help is appreciated.

 

[Rivenin]

are you checking with a hydrometer? or refrectometer?

 

[hoosier2137]

Hydrometer.

 

[Psylocide]

Was that 68° ambient temp or wort temp?

Is your thermometer that you used for mash temp calibrated?

What method are you using? Three vessel? BIAB?

 

[brew_darrymore]

Did you manage to maintain your mash temperature for the entire time? It probably went down by a degree or two by the end of your mash, and temperatures near 150 or below would produce more fermentable wort.

Check your thermometer as well to make sure it gives accurate readings.

 

[balrog]

All of the above, and is there any off taste like vinegar?

 

[hoosier2137]

Was that 68° ambient temp or wort temp?

Is your thermometer that you used for mash temp calibrated?

What method are you using? Three vessel? BIAB?

68F is according to the stick on car it thermometer.

It's only a month old so I'm assuming it is.

3 vessel

 

[hoosier2137]

Was that 68° ambient temp or wort temp?

Is your thermometer that you used for mash temp calibrated?

What method are you using? Three vessel? BIAB?

68F is according to the stick on car it thermometer.

It's only a month old so I'm assuming it is.

3 vessel

 

[hoosier2137]

Ambient was around 66F.

I haven't tried the beer yet but I will taste for vinegar.

 

[hoosier2137]

Stick-on carboy* @psylocide

 

[Rivenin]

It's only a month old so I'm assuming it is.

never assume an out of box thermometer is correct - they can vary a ton.
i've bought one before that was 7-8* off

stick it in boiling water and see if it shows 212