Fgs Using Darker Malts

[The King of Spain]

I brewed the Schwarzbier on Ross's web site Link
but reduced the Pilsner and Munich to get 5kg that I can fit it all into my tun. I got an OG of 1.05 which is pretty standard for a 5kg bill with my set up. Here is the thing though, a 64C mash with rainwater (1 tsp of Gypsum included) I have finished at 1.018. I usually get ~1.011 FG for a lager using S189 with no dark grains and 1kg of rice flakes in my regular lager bill .. so whats different? This has happened before when I get into darker grain.

I read in Palmers books that the high acid in dark grains makes it a good practice to seperate them for a late addtion to the mash. What do you guys do (that are getting lower FGs than me) with your Schwarzbier/dark grains?

Any expert experience on this welcome.

 

[underback]

Some interesting reading in this article to explain the likely causes of lower attenuation when using darker malts.

http://www.scientificsocieties.org/JIB/pap...05-0330-275.pdf

I'm also surprised that at 64C you are not getting an even lower FG with your pale lagers considering. Could be your thermometer is just a couple of degrees out?

Cheers

 

[wessmith]

Some interesting reading in this article to explain the likely causes of lower attenuation when using darker malts.

http://www.scientificsocieties.org/JIB/pap...05-0330-275.pdf

I'm also surprised that at 64C you are not getting an even lower FG with your pale lagers considering. Could be your thermometer is just a couple of degrees out?

Cheers

An interesting article that digs pretty deeply into the theory of fermentability of darker malts. But if you check out the potential extract figures for any crystal/munich/roasted malt you will see that this lower fermentabilty has already been factored in. Promash and Beersmith have these numbers already loaded for a range of generic specialty malts.

Lets keep it simple! I also agree that at 64C the FG should be lower with pale malts. I would think the problem is in the rainwater - it will need more than just gypsum to bring the mineral content into line for brewing.

Wes

 

[underback]

Wes I know that potential extract is factored for various malts. But potential extract it isn't the same as attenuation, unless the program can account for this also. I suspect you could be right on the rainwater theory.

Cheers

 

[The King of Spain]

I will try adding the dark malts in the last 30min of the mash and post back here next time

What confused me is that I got a pretty std OG (1.050) from 5kg. T thought mash Ph etc would have effected my OG more than my FG

Cheers