Dusseldorfer Altbier

• Dusseldorfer Alt - Altbier (7 B)
  
  Description:
  Type: All Grain
  Batch Size: 23.0 l
  Pre Boil Volume: 29.6 l
  Pre Boil Gravity: 1.039
  Boil Time: 90 min
  End of Boil Vol: 26.2 l
  Final Bottling Vol: 22.5 l
  Fermentation: Cool fermented Ale 12-16 °C, plus lagering
  OG: 1.046
  FG: 1.009
  ABV: 4.9 %
  Bitterness: 32.5 IBUs
  Color: 14.7 SRM
  Mash: 65°C, 2.75 : 1 (water vs grain), no mash out
  Mash Step: Add 14.0 l of water at 72.7 °C,  60 min
  Sparge Water: 21.2 l
  Sparge Temperature: 77.0 C
  Brewer: !@MMi
  Equipment: Robobrew
  Efficiency: 70.00 %
  Est Mash Efficiency: 77 %
  Carbonation: 2.5 Volume of CO2, 150 gr dextrose
  
  Ingredients:
  3.20 kg Pilsner, Franco Belge, L=1.7
  0.60 kg Munich, L=8
  0.40 kg Caramunich-40, L=40
  0.40 kg Melanoidin, L=25
  0.40 kg Vienna, L=4
  0.10 kg BlackPrinz, L=500
  16 g Magnum [12.0 %] - First wort 90 min
  14 g Hallertau [4.8 %] - Boil 30 min
  1 tab Whirfloc - Boil 15 min
  14 g Hallertau [4.8 %] - Boil 15 min
  1 pkg German Ale (Wyeast #1007)
  1 pkg Nottingham (substitute)

Dusseldorfer Altbier is a style of beer that originated in the Dusseldorf-region of Germany. 
Altbier - which means 'old beer' in German - refers to the period before brewers started to make lager fermented beers. Alt is an ale fermented beer and after fermentation, the beer is lagered (cool stored), leading to a cleaner, crisper beer than is the norm for some other top-fermented beers such as British ales.