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Old 10-08-2013, 05:26 PM   #1
Math0
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Default Fermentation temperature variation

I did 3 mini-mash kits about 2 weeks ago and all the OG were between 1.045 and 1.049 (estimated OG were 1.049 and 1.050). I am using the Nottingham yeast for all of them. I mashed at 154-152F for 1 hour. Refractometer is accurate and thermometer also (I checked). The 3 kits seems to be stuck around 1.020.

What I do is I put my primary in my wine cellar at 17C for 2-3 days so the fermentation doesn't go in the airlock (and because of the heat in the beer) then I move the primary to room temperature to proceed with fermentation (21C). After 10 days, I transfer to secondary and bottle when ready.

Is it normal to get a FG of 1.020 with a mini-mash kit? The kits estimate FG at 1.011 and the other one at 1.014.
Can the temperature change when fermenting stop the process?
What could possibly be the issue?

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Old 10-08-2013, 05:32 PM   #2
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It seems that your fermentation temps are just about perfect (62F stepped up to 69F). There shouldn't be any reason that a mini kit would have a different FG than a larger batch, the process should all be the same. I suspect something else is the culprit.

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Old 10-09-2013, 02:42 PM   #3
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Did you rehydrate your yeast? What form of aeration did you use prior to pitching?

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Old 10-09-2013, 05:02 PM   #4
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It sounds like you're probably using a refractometer for your FG reading. You should use a hydrometer, as the refractometer reading will be off once alcohol is present.

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Old 10-09-2013, 05:42 PM   #5
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I did use a starter solution 1 day prior to brewing every batch! And I shook well enough the wort before pitching the yeast in. I don't know if this makes a difference but I pitched the yeast at fridge temperature in a room temperature wort.


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It sounds like you're probably using a refractometer for your FG reading. You should use a hydrometer, as the refractometer reading will be off once alcohol is present.
You are saying that using a refractometer to get FG is bad? So what's the point of buying one if I cannot use it all the time? I calibrate it every time with water before and I assume a margin of error of about 0.002.
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Old 10-09-2013, 05:50 PM   #6
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You are saying that using a refractometer to get FG is bad? So what's the point of buying one if I cannot use it all the time? I calibrate it every time with water before and I assume a margin of error of about 0.002.
It's useful for things like checking to see if the beer is done fermenting, or to see if your sparge run-off gravity has gone below a particular level (at which point you might start extracting tannins), and of course for OG. You can use a refractometer alcohol correction formula (Google "refractometer alcohol correction".), to estimate your true FG, but it's more accurate to use a hydrometer. The presence of alcohol raises the refractive index of the solution, counteracting (somewhat) the drop you see from the yeast eating sugars in solution.
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Old 10-10-2013, 08:10 PM   #7
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Actually... That was my mistake. Feeling dumb right now

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