US-05 attenuated my AAA to 1.004???

[bell0347]

I brewed an AG American Amber a few weeks ago. It was a small 3 gallon batch that contained 1lb of caravienne and .25lb crystal 120. .25lb toasted 2 row and several lbs of 2 row pale. I broke the hydrometer prior to brewing that day so I don't know my OG. Should be around 1.052 or so. Pitched and fermented at 66F for two weeks then bottled. FG at bottle time was 1.004! Hydro sample was tasty but dry and very alcoholic. What caused this? I've used 05 before and it never attenuated like that. Was it the relatively high amount of caramel type malt? Mash temps were around 153F.

 

[blackwaterbrewer]

did you use the whole package of yeast?
i think those are made for a 5 gallon batch.

 

[Saccharomyces]

Check your thermometer... I doubt you mashed at 153*F if you got over 80% attenuation. 150 maybe...

 

[david_42]

I'd agree on the thermometer check. High caramel levels should reduce attenuation, since the caramels are unfermentable.

 

[Cpt_Kirks]

05 will surely suck down the sugar.

I'm brewing a light amber ale with it this weekend.

Good stuff.

 

[bell0347]

Well, bought a new thermometer, a "lab" type instead of the floaty kind with paper scale inside assembled by some chinese kid that does not care how well my beer turns out. So, if it was the mash temp. that should be resolved. I did pitch the entire packet in the 3 gallon batch. But I am not sure that would cause over attenuation. Thanks for the suggestions though!

 

[mmb]

Well, bought a new thermometer, a "lab" type instead of the floaty kind with paper scale inside assembled by some chinese kid that does not care how well my beer turns out. So, if it was the mash temp. that should be resolved. I did pitch the entire packet in the 3 gallon batch. But I am not sure that would cause over attenuation. Thanks for the suggestions though!

Over pitching will push the attenuation higher and affect the flavor profile.

US-05 goes gangbusters anyway. Mash temp was probably lower than you thought as well.

 

[Dubcut]

Over pitching will push the attenuation higher and affect the flavor profile.

As a novice brewer, I am a little perplexed by this. Also because I pitched two viles of yeast to a split batch 3g/2g yesterday. How can this be, when it is encouraged to make a starter?

 

[usurpers26]

Mr Malty Pitching Rate Calculator

You pitched two times the amount of yeast you needed.

I brewed an AG American Amber a few weeks ago. It was a small 3 gallon batch that contained 1lb of caravienne and .25lb crystal 120. .25lb toasted 2 row and several lbs of 2 row pale. I broke the hydrometer prior to brewing that day so I don't know my OG. Should be around 1.052 or so. Pitched and fermented at 66F for two weeks then bottled. FG at bottle time was 1.004! Hydro sample was tasty but dry and very alcoholic. What caused this? I've used 05 before and it never attenuated like that. Was it the relatively high amount of caramel type malt? Mash temps were around 153F.

 

[Dude]

I'm pretty sure over-attenuation doesn't have anything to do with pitch-rate.
It can be opposite (underpitching can affect attenuation) but not by overpitching.

I think either you have some wild yeast bringing it that low, or some other factor.

I use US-05 a ton and I've never seen it go that low. It is quite unreliable as far as attenuation goes, but something else is happening there.

Would love to see a reference for how overpitching affects over-attenuation. Methinks that is bunk.

 

[HairyDogBrewing]

No one has asked yet, so I will ...
Did you check your new hydrometer against plain water?
They can be off by a bunch.

 

[Bobby_M]

There's some truth to the overpitching thing but not THAT much. In my dry yeast experiment, 4 test samples were pitched to the recommended 11g/5 gallon rate and went down to 1.014fg. I had a control sample setup that was pitched to something like 7g/2qts which is like 14x the normal pitch rate and it fermented to 1.010.

To the OP, I think there's a chance that either you really mashed at 147F or you picked up some kind of stray contaminant.