Author Topic: Attenuation  (Read 5910 times)

Offline cheba420

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Re: Attenuation
« Reply #15 on: July 21, 2012, 10:32:41 AM »
I was under the impression that Chico topped out at 80% attenuation.
There's really no such thing as a yeast "topping out". The fermentability limit of the wort is set in the brewhouse, and with a low-flocculating strain like Chico, the FG should always be very near that limit.

Just for reference, our standard mash at the brewery is 153.5°F, which gives a target FG of 2.5°P given a 12°P OG. That's 79% ADF, and obviously we could mash several degrees lower to increase that. Normally, I'd suggest that you calibrate your mash thermometer, but given that your results are exactly in line with what I see 4-6 times a week, I think you are actually mashing at about 152°F, and getting the fermentability that would be expected from that mash.

I very much doubt you have a contamination issue. There just isn't enough "surplus" attenuation happening.
Thanks for the breakdown. But it poses another question. If the recipe calls for a 152 mash and targets a 1.013 FG using the chico yeast and I am hitting that 152 and getting 1.008 FG with that yeast, theres something wrong there. What are your thoughts? Thermometer calibration? Perhaps my thermometer is reading 152 but I'm actually at 148 or so thus giving me a more fermentable wort and higher attenuation?
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Offline a10t2

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Re: Attenuation
« Reply #16 on: July 21, 2012, 11:12:32 AM »
Maybe the rest length was different. Maybe the person who wrote down the recipe didn't have a calibrated thermometer, or a calibrated hydrometer, or both. Or had a stalled fermentation on that batch, for whatever reason. Or maybe it's just a typo.

There are so many variables to consider that I doubt you'll ever get a definitive answer. All you can do is try to be as accurate and precise in your own measurements as possible, and keep your notes so that you can replicate or adjust in the future.
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Offline DrewG

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Re: Attenuation
« Reply #17 on: July 23, 2012, 07:45:12 AM »
I kegged an IPA yesterday, mashed at 153 that finished at 1.008 with chico. I regularly have beers that finish that low with 001. I wouldn't worry about it. If you want 1.012 with that recipe just mash it higher and find the sweet spot for your system
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Offline lazydog79

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Re: Attenuation
« Reply #18 on: July 26, 2012, 12:39:14 PM »
Thanks for the breakdown. But it poses another question. If the recipe calls for a 152 mash and targets a 1.013 FG using the chico yeast and I am hitting that 152 and getting 1.008 FG with that yeast, theres something wrong there. What are your thoughts? Thermometer calibration? Perhaps my thermometer is reading 152 but I'm actually at 148 or so thus giving me a more fermentable wort and higher attenuation?

I've come to learn that mash temps, as with many other things, depend on your system.  I have figured out that a 150-152 mash on my system is like a mid 150s mash for some other people, and a mid-fifties mash is like an upper 50s.  Could be the thermometer, could be some other factors.  The key is figuring your system out.

I agree with several of the others, Chico is great if you want a madman of a yeast that is going to be a high attenuater, can take some manhandling, and will leave your beer fairly dry.  I will still use it for APAs, IPA's, etc.  It's not the yeast for you if you want a nuanced malt profile.  It used to be my "house yeast" but it doesn't really fit my goals for what I'm trying to brew.  Once size doesn't always fit all.