Attenuation Question

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bakeup

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I just bottled my first AG batch. When I measured my FG, it seemed low at 1.007. My OG was 1.051, and I used WL001. The FG seems a little bit low for the yeast and mash. I mashed at 158 for an hour, and the temp stayed within 1 degree over the hour, which should make it less fermentable.

Is there something else that that would make a difference in fermentability that I am missing, or something with the yeast? I did do a 1L starter, and fermentation began within a few hours. Would that make a difference in attenuation?
 
most likely:

1- your hydrometer is off.. check it in plain water, it should read 1.00
2- your thermometer is off and you mashed much lower than you think
3- you fermented at too high of a temperature
4- you had a bunch of sugar in the mash (corn/table etc)
5- some combination of the above
 
most likely:

1- your hydrometer is off.. check it in plain water, it should read 1.00
2- your thermometer is off and you mashed much lower than you think
3- you fermented at too high of a temperature
4- you had a bunch of sugar in the mash (corn/table etc)
5- some combination of the above

Thanks.

My hydrometer is good; I checked.
I'm pretty sure my thermometer is good; it reads 100C in boiling wort.
My ferm could be too high; it was in the low 70s.
I didn't add any sugar to the mash.

The beer still tastes good. I just want to know where my shortcomings are and address them. I know I need better fermentation temperature control, and this just further shows that that is the case.
 
86% ADF isn't all that high for 001. I've mashed as high as 72°C in order to keep attenuation in the 70s when using that strain.

It's entirely possible that your thermometer is accurate at boiling but not at mash temps, though.
 
also, don't get too hung up on the numbers. How does the beer taste? Attenuation and final gravity numbers can be very misleading. Ultimately the taste is what's important.
 
Post ferment taste was good. How much are FG and body related?
 
bakeup said:
Post ferment taste was good. How much are FG and body related?

That is difficult to answer. Body is based on alot of factors. For instance, if you had a low FG that had low carbonation, you might petcieve it to have good body. The same beer more carbonated can seem to have a lighter body. Head, sweetness, hops, these and more all play a role in perceiving body.
 
certainly, FG measures the remaining dextrines and that effects body but it's not that simple. Dextrines are just one part of the picture. So, don't go crazy with the numbers. If the beer tastes good then RDWHAHB

But getting back to your mash out. Did you do one? How quickly was the wort heated above 170F If you do not heat the wort ASAP the enzymes will continue to break down the dextrines and you end up with a more fermentable wort.

and WLP001 is one of the most highly attenuative yeasts.
 
did you do a mash out?

No mash out.

86% ADF isn't all that high for 001. I've mashed as high as 72°C in order to keep attenuation in the 70s when using that strain.

It's entirely possible that your thermometer is accurate at boiling but not at mash temps, though.

I was just going by the data sheet for 001, but I was thinking that was just typical and could go outside that.

Regardless of the numbers, it's still good beer.
 
certainly, FG measures the remaining dextrines and that effects body but it's not that simple. Dextrines are just one part of the picture. So, don't go crazy with the numbers. If the beer tastes good then RDWHAHB

But getting back to your mash out. Did you do one? How quickly was the wort heated above 170F If you do not heat the wort ASAP the enzymes will continue to break down the dextrines and you end up with a more fermentable wort.

and WLP001 is one of the most highly attenuative yeasts.

No mash out. I didn't heat quickly, and that makes sense. I will have to remember that for next time. Thanks. That really helps.
 
Yes, and more than likely as indicated above, the yeast is a beast. You HAVE to mash very high, or use a ton of crystal malts to keep it from really drying out.
 
How quickly was the wort heated above 170F If you do not heat the wort ASAP the enzymes will continue to break down the dextrines and you end up with a more fermentable wort.

At what temp do they stop working, I mashed out a brew at 165ish (my first AG) and then it sat for 30min while I tamed the zoo of kids at my place before I got back to brewing. And if the temp drops back down to 150/140ish does that mean that it starts again or does the 170 kill the enzymes?

Clem
 
Clementine said:
At what temp do they stop working, I mashed out a brew at 165ish (my first AG) and then it sat for 30min while I tamed the zoo of kids at my place before I got back to brewing. And if the temp drops back down to 150/140ish does that mean that it starts again or does the 170 kill the enzymes?

Clem

At 170 the enzymes are dead and cannot be awaken again.
 
At 170 the enzymes are dead and cannot be awaken again.

170°F is pretty marginal as far as denaturing enzymes goes. Ideally you want to get to at least 80°C (176°F). And then you need to hold that temperature for at least 15 min for all the proteins to be completely denatured. Briefly heating the mash and then allowing it to cool again isn't enough.
 
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