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?

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.

Did you rehydrate your yeast? What form of aeration did you use prior to pitching?

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.

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.

afr0byte said:

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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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.

Math0 said:

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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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.

Actually... That was my mistake. Feeling dumb right now