Why do I never hit the brew mate FG?

Discussion on brewing beer from malt extract, hops, and yeast.
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lad

Why do I never hit the brew mate FG?

Post by lad » Tue Aug 09, 2011 11:07 pm

Designed my last 3 brews with the Brewmate software and never seem to hit the stated FG, the last one was spot on OG but after 3days it stayed the same at 1.012 when the software stated 1.006, I have allowed for temperature too, any ideas?BJ's Best Bitter (Bitter)

Original Gravity (OG): 1.041 (°P): 10.2
Final Gravity (FG): 1.006 (°P): 1.5
Alcohol (ABV): 4.57 %
Colour (SRM): 8.9 (EBC): 17.5
Bitterness (IBU): 50.2 (Average - No Chill Adjusted)

50% Liquid Malt Extract - Light
33.33% Dextrose
16.67% Crystal 60

3.3 g/L East Kent Golding (4.7% Alpha) @ 60 Minutes (Boil)
1.1 g/L East Kent Golding (4.7% Alpha) @ 10 Minutes (Boil)

0.0 g/L Irish Moss @ 10 Minutes (Boil)
0.0 g/L Malto-Dextrine @ 0 Days (Primary)

Single step Infusion at 66°C for 60 Minutes. Boil for 60 Minutes

Fermented at 20°C with Safale S-04

Notes: Strike Temp 68c

4lt mash



To commemorate the Birth of our 3rd grandchild.

Recipe Generated with BrewMate

lad

Re: Why do I never hit the brew mate FG?

Post by lad » Tue Aug 09, 2011 11:10 pm

Sorry! reading it back it looks like I only fermented for 3 days, it was 11 actually, what I meant to say was that the reading was the same from the 9th day.

DaveyT
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Re: Why do I never hit the brew mate FG?

Post by DaveyT » Tue Aug 30, 2011 10:38 pm

Hello
It might have something to do with your yeast and how it's behaving. The end of fermentation is when the yeast has either run out of sugar (in this case maltose) or it's run it's cause. The strain/batch/packet might have run it's cause within the conditions you have set for it. As it has happened three times, it looks like you are being consistent with your brewing which is great. I also hit these kind of FGs and I don't know why the software expects me to hit anything different.
Apparently, many kits are designed to only go as far as 1.014 or so. And Turbo yeast is designed to go as far as 0.090 or some such. As Turbo digests sucrose, though, it would no use in a beer brew.
I have used US-05 and got down to 1.008 but nothing further than this. US-05 is famously dry. If a yeast is designed to give a sweet flavour I can imagine the designers want some sugars left over for that specific taste.

Cheers
David
Evolution didn't end with us growing thumbs.
Bill Hicks

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