Thin mashing = Extreme US05 Auttenuation. or?

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Bonde

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Attenuation with S-05

I had a few beers going quite low recently. I know the first thing that spring to mind is an infection here in the summer time but I very much doubt it due to my process and the looks/taste of it.

But, the last supposed to be, session Centennial IPA went from 1053 to 1006in 5 days (today). I’ve never seen that before and I’ve been quite hysteric about cleanliness recently due to a few very low fgs. No sign of infection though.

Is a thin mash really capable of making the worth that much more fermentable? 88%.

Mashed 1:5.5 so quite thin.
 

Obliviousbrew

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More than the thin mash I´ll check on you mash temp, if temp is very low or you do a long protein rest for a long time with well modified malts you can get this, US-05 is a working horse too, some people have reported a low FG with it, I´ve used quite a lot and never had those problems, did you checked that you hydrometer is accurate?
 
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Bonde

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Had 2 thermometers going due to the recent problems with low fg. And even crosschecked them before brewing with 2 other thermometers.
Single infusion mashed at 68-69c (154-156) for aprox 2 hours incl. sparge (mashed 65) Also another crazy thing 11% crystal, that really speaks aginst the low fg.
 

HollisBT

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A thinner mash will make a more fermentable wort, but like above, I think you might look more into your mash temps and also tell us your grain bill.


88% AA is pretty astonishing though.
 

duboman

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+1 on mash temp, if you were below 150 you got a much more ferment-able wort and greater attenuation. Is your thermometer calibrated? You may be mashing much lower than you think:) Also, at what temperature are you fermenting at, high temperatures will cause fast and furious fermentations as well as off flavor production depending on the yeast.

Edit: WOW, two posts before I finished typing!
 
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Bonde

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Grain bill:

Pale 66%
Crystal 120 11%
Munich 11%
Flaked Oats 11%

In terms of thermometers, I must admit that I do not use state of the art thermos. But 4-5 cheap digital ones. Threw 2 away as they were 2c off. Chose the one in the middle of them all, and hoped for the best, maybe not that good after all.

Fermentation temps are at a steady controlled 67.1f
 

weirdboy

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I have (deliberately) gotten over 90% attenuation with US-05.

A 2 hour mash is pretty long, and likely to result in a more fermentable wort. If your thermometers are off by a degree or two, you are more likely to favor beta amylase and break down those complex sugars a bit more than you may have expected.
 
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Bonde

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I have (deliberately) gotten over 90% attenuation with US-05.

A 2 hour mash is pretty long, and likely to result in a more fermentable wort.
Above 90% now thats crazy...

i thought i was crazy when my french Saison hit the late 90'ies... but us05...

The 2 hours was including batch sparge, the normal mash took 65min.
 

jtejedor

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I would check thermometer as others have stated. I used to get crazy attenuation but now that I am using a thermopen my numbers are more in line with what they should be. That is a pretty thin mash though. I even do overnight mash and my attenuation numbers are still pretty close.
 

Denny

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Above 90% now thats crazy...

i thought i was crazy when my french Saison hit the late 90'ies... but us05...

The 2 hours was including batch sparge, the normal mash took 65min.
Waidaminnit....are you saying you batch sparged for an hour?
 
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Bonde

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Waidaminnit....are you saying you batch sparged for an hour?
Almost yes :) But not intentionally, something came up in the middle of sparging. It’s a difficult job sometimes with a little kid and brewing at the same time :)
 

ArcLight

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2 hours vs 1 hour might not make that much difference.
But coupled with a lower mash temperature, such as 148, certainly could.
While Alpha Amylase will be slower acting, it will act, and that will expose additional molecules to Beta Amylase.

1.5 quarts / 1Lb is not a thin mash. 1.25 - 1.5 is a "normal" mash when using a cooler (at least in many parts of the USA).

Mashes at 2+/1 may extract more sugars than the traditional 1.25/1
 

Obliviousbrew

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What about BIAB then? that´s a diluted mash and I don´t think high fermantability it´s a problem if you BIAB. Low mash temps not only because of the alpha or betha amylase but also for the breakdown of proteins, a lot more aminoacids (read yeast food) plus a very fermentable wort plus US-05 can lead you to this problems.
 
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