Low Final Gravity

[ErsteBrau]

Hi All,

I'm up to my third brew now - all extract brews to get my experience up. Each problem I've had is that the final gravity has been too low. My first three batches has been (OG/FG):

1.041 / 1.020 - A lager which I arsed up, didn't rehydrate yeast (21 litres)
1.052 / 1.018 - Wheat beer, fermentation temp stable at 18 degrees(64 f), rehydrated yeast (19 litres)
1.045 / 1.015 - Same Wheat beer, fermentation temp stable at 18 degrees (64 f), rehydrated yeast, but used double the amount of yeast (21 litres)

So, has been a bit frustrating as the alcohol content is lower than I want. The kits I'm using are Mangrove Jacks. Does anyone have any ideas? The only other solution I thought is maybe having a fermentation temp of about 20 degrees (68 f) or more?, but am welcome to any ideas and experimentation!

Thanks muchly,
Doug

 

[C-Rider]

What do the kits say you should finish at?
How long are you fermenting?

 

[AT-JeffT]

Do you mean you FG has been too high(numerically)? Extract has issues fermenting to low gravities. 1.015 is a very reasonable FG for an extract wheat beer. Partial mashes would help hit lower gravities. Also, a more fermentable sugar would help lower the final gravity, dry out the beer and produce more alcohol. Try adding 5% corn sugar (dextrose) or Table sugar(sucrose).

 

[rodwha]

Are you aerating the wort well enough at pitching time?

Your temp is likely good, though it depends on the yeast.

The only other issue might be the amount of time you are allowing it to ferment?

Or maybe you have a temp swing that drops the temp lower, like at night possibly? I stalled my beer this way and added a little sugar and a gentle stir to rouse the yeast.

 

[ErsteBrau]

Hey, thanks for the feedback. The kit reckons the final gravity should be 1.010. Being a perfectionist, I want to hit this. This time I'm putting the fermentor in a slightly warmer area and will see how it differs.

Thanks Comrades

 

[rodwha]

The FG is just an assumed FG. Your FG can hit a little above or below that, but should be close.

 

[GibbyGibson]

Hey, thanks for the feedback. The kit reckons the final gravity should be 1.010. Being a perfectionist, I want to hit this. This time I'm putting the fermentor in a slightly warmer area and will see how it differs.

Thanks Comrades

Check the info on your particular yeast strain from the manufacturer before you bump up the temp. I'd start on the low end of what they recommend and when fermentation slows, gradually increase the temperature to the upper limit of the yeast strain.