Why more attenuation?

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hotbeer

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I've just started looking at attenuation and thinking about how ABV might be changed in a recipe. So bear with me, I've been reading and trying to make connections from what I've read and what I'm getting.

A batch in the fermenter looks likes it's going to finish at a FG or 1.010. It started at 1.070 which is about 85% attenuation. The yeast was US-05 which lists apparent attenuation at 74 - 82%.

  1. I did miss my mash temp of 154°F and was just under 150°F most of the time. Is this the likely reason for the attenuation being more.
  2. Or is it just a quirk of something else because with more fermentable sugars the wort should have still had an apparent attenuation of 74 - 82%?
  3. 3% is too little to worry about, go have a beer!

I used a real hydrometer, temps pretty much 68°F when SG taken.
 

DBhomebrew

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Recipe and software-derived FG prediction are notoriously inaccurate. For example, most softwares do not account for grist composition.
 

Kickass

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I try to think in terms of high, medium and low attenuation. Then adjust within those parameters, rarely worried about +/- 5%.

Notes help also. Next time you can look back and reference where you finished for this given recipe.

Also, US-05 commonly gets to 85% for me.

Lastly, shoutout to @VikeMan recipe builder. One of the better ones, IMO, accounting for factors that influence attenuation.
 

dmtaylor

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Their listed range is low. I have used US-05 a lot and I've averaged 83% attenuation with it. It is one of the highest attenuators of all "neutral" dried yeasts. If you want to try a similar neutral yeast with lower attenuation, next time try S-04 or Nottingham instead. They average about 77-78%.

Your mash temperature also made a little difference, but not as much as you might think.
 
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hotbeer

hotbeer

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Thanks for all the answers, it sort of is starting to gel in my head.

There is an IPA I've brewed several times and I'd like to change the recipe to be a lower ABV. And I've been playing with the base malts and realized I didn't really understand attenuation other than just the definition.

I think more question will follow later. But probably need to be a different thread.
 
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