Fermentation sometimes has very strange SG reading

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rjenman

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Hi

I have made a pretty good brew that consistently starts at about 1.032 SG and usually ends at 1.010 , however twice now it's ended at 1.020

(I'm brewing an ale, leaving it in a fermenter for 7 to 10 days , taking the "end" SG reading and then bottling it up.)

I'm trying to figure out what's going wrong with the batches that end at 1.020 ... the first was in a cold spell in Brisbane, with temps likely several degrees below 12C and adding more Yeast and leaving it for another week did nothing (assuming it died).

Surprisingly, despite the SG remaining at 1.020, bottling the beer resulted in beer with full strength alcohol content. As i assumed the SG would reflect alcohol content. However it has a very thick and unrefined, comparatively dirty sort of consistency and is "drinkable" rather than "good"

I assumed it was temperature, but now I've just done a batch in perfect weather (15C to 22C all day every day) and it's happened again. Does anyone have any idea as to the factors causing this? My only guess is that brewing without temperature control is inconsistent in results and maybe I should double the yeast I put in to make it work, but I'm very thrown off by the fact it still seems to have full alcohol content.

I guess it could be the temperature that I Mash, but I'm skeptical that it makes that much difference. I may try really carefully to recreate the temperature conditions recorded on my successful batches to make the wort identical. But I find it hard to believe that 10 degrees celcius mashing malt makes such an extreme difference in the quality of the beer.

Have a good one and don't drink too much
 
Welcome to AHB.
We really need more information to form a view of what's happening here.
What is your recipe, and what volume are you brewing?
How do you measure your SG and your FG, and at what temperature are you doing so?
And yes, a 10ºC difference in mashing makes a potential huge difference in your predicted FG.
Let us know and we'll have crack at figuring out what's happening.
 
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