Reasons For Low Final Gravity?

[nick_lavender]

My last few all grain batches of beer have ended with lower FG's than they should have.

I ferment them with 11 g's of ale yeast at the recommended temp and usually bottle after 7 days in the primary.

The OG's have always been on target, and they still carbonate well in the bottle.

I'm also fairly sure its not a problem with the hydrometer.

So, what else could it be?

Cheers.

 

[bconnery]

My last few all grain batches of beer have ended with lower FG's than they should have.

I ferment them with 11 g's of ale yeast at the recommended temp and usually bottle after 7 days in the primary.

The OG's have always been on target, and they still carbonate well in the bottle.

I'm also fairly sure its not a problem with the hydrometer.

So, what else could it be?

Cheers.

Mash temp.
Sounds like you are getting a lower mash temp than you planned.
If you mash lower then you finish lower.

You can either up the initial temperature of the water you are adding to your mash and/or increase your insulation.

That would be my guess, barring some sort of infection, which can cause more sugars to be eaten. But if they taste fine then this is unlikely to be it...

 

[BenH]

My last few all grain batches of beer have ended with lower FG's than they should have.

It depends on what you mean by "lower" and what you mean by "should have".

Some styles require high attenuation. The cause is more than likely to be your mash temperature, but also depends on the amount of yeast you pitch (though I know you've said you use 11g of dried yeast), and the oxygenation of the wort and fermentation temperature.

I get some very high attenuation beers by mashing at 68 degrees, pitching a lot of yeast starter and oxygenating as much as I can. Produces drier, crisper beers which I've found are more palatable to my mates (though I'm a malt head :wub: ).