Author Topic: How to tell if I have a stuck fermentation or FG  (Read 260 times)

Offline hopsgo

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How to tell if I have a stuck fermentation or FG
« on: September 07, 2017, 11:21:00 PM »
Hey guys,

I brewed an all grain Firestone Wookey Jack clone with Wyeast London ESB. Attenuation is 67-71. I pitched two packets of the yeast and gave it some good shakes, though I wouldn't doubt I could have done a bit better oxygenating it. Target OG was 1.080 and I measured at 1.077.

According to the recipe, my target FG is 1.015, but I'm about day 10 in primary and my gravity is 1.017. It hasn't had any movement in days and the krausen was fallen when I took the sample just now. Should I assume it's done? I'm not sure how big a leap each of these numbers actually are, so I don't know if I should label myself a perfectionist and sit down, or worry that it's stuck. It does taste a bit sweeter than I had expected, but pretty good otherwise.

Advice would be great. I'm going to start my dry hop on day 11.

Also, how much time do you guys usually give for a diacetyl rest? I'm following the recipe I have, but thoughts on that are welcome also.

Thanks!

Thanks!

Offline Ck27

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Re: How to tell if I have a stuck fermentation or FG
« Reply #1 on: September 08, 2017, 12:02:01 AM »
Hey guys,

I brewed an all grain Firestone Wookey Jack clone with Wyeast London ESB. Attenuation is 67-71. I pitched two packets of the yeast and gave it some good shakes, though I wouldn't doubt I could have done a bit better oxygenating it. Target OG was 1.080 and I measured at 1.077.

According to the recipe, my target FG is 1.015, but I'm about day 10 in primary and my gravity is 1.017. It hasn't had any movement in days and the krausen was fallen when I took the sample just now. Should I assume it's done? I'm not sure how big a leap each of these numbers actually are, so I don't know if I should label myself a perfectionist and sit down, or worry that it's stuck. It does taste a bit sweeter than I had expected, but pretty good otherwise.

Advice would be great. I'm going to start my dry hop on day 11.

Also, how much time do you guys usually give for a diacetyl rest? I'm following the recipe I have, but thoughts on that are welcome also.

Thanks!

Thanks!

Give it 4 more days and if it doesn't move then you are done, it wont hurt if its off just a few points.

Offline jtoots

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Re: How to tell if I have a stuck fermentation or FG
« Reply #2 on: September 08, 2017, 08:45:30 AM »
Close enough, if a bump up in temp for a couple days doesn't finish it out I'd call that batch a success either way.

Offline Kevin58

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Re: How to tell if I have a stuck fermentation or FG
« Reply #3 on: September 08, 2017, 10:38:34 AM »
That is so close I wouldn't even question it.

Offline Oginme

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Re: How to tell if I have a stuck fermentation or FG
« Reply #4 on: September 08, 2017, 11:37:52 AM »
I totally agree with what Kevin58 and Jtoots have said.  Estimation of FG is far from perfect given the vast number of factors which may affect the wort fermentation.  If I am within a couple of points and the value is stable over a few days, I am happy with calling it done and bottling.
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