Bamberg Rauchbier

(5 gallons/19 L, all-grain)
OG = 1.054  FG = 1.013 IBU = 30  SRM = 18  ABV = 5.3%

Ingredients

4.0 lbs. (1.8 kg) Pils malt (<2° L)
2.0 lbs. (0.91 kg) Munich malt (10° L)
3.0 lbs. (1.4 kg) Weyermann smoked malt (2–3.5° L)
0.5 lb. (0.23 kg) dextrin malt
0.5 lb. (0.23 kg) Vienna malt (2–3.5° L)
1.0 lb. (0.45 kg) Weyermann Caramunich® II (~45° L)
3 oz. Weyermann Carafa® Special III (450–488° L)
6.7 AAU German noble hops, such as Hallertauer or Tettnanger (75 min.) (1.5 oz./43 g of 4.5% alpha acid)
0.75 oz. (21 g) German noble hops, such as Hallertauer or Tettnanger (30 min.)
0.75 oz. (21 g) German noble hops, such as Hallertauer or Tettnanger (15 min.)
2 packages of Wyeast 2206 (Bavarian Lager) or White Labs WLP830 (German Lager)
1 cup DME or corn sugar (for bottling)

Step by Step

Rauchbier-mashing involves several rests. To imitate the original Bamberg method, dough in at a cool 113 °F (45 °C) and keep the temperature at that level for about 30 minutes. Next, infuse the mash slowly with very hot water, while stirring gently, to raise the temperature by about 2 °F (1 °C) per minute to 149 °F (66 °C) for another 30-minute rest. At 149  °F (66 °C), beta amylase enzymes are at their peak performance, while alpha amylase have become active as well (they start at 140 °F/60 °C). The optimum target pH value for a rauchbier mash is around 5.0. Infuse the mash again with hot water to reach 162 °F (72 °C) for yet another 30-minute rest. At this temperature, alpha amylase reach their peak performance. Finally infuse the mash to reach 170 °F (77 °C). This is the temperature you should maintain for the duration of a 90-minute sparge. Boil time for the wort is at least 90 minutes, but two hours is better, because a longer boil promotes wort browning from melanoidins. Add the bittering hops about 15 minutes into the boil, the flavor hops about 30 minutes before shut-down, and the aroma hops about 15 minutes before shut-down. Check the gravity at the end of the boil and compensate for evaporation losses by adding cold water to the fermenter. Heat-exchange the wort to roughly 55 °F (13 °C) and aerate. Primary fermentation lasts about seven days, at which point there should be a gravity drop of about 90% of the difference between OG and FG. Rack the brew, and start reducing the brew’s temperature by about 2 °F (1 °C) per day to as close to 28 °F (-2 °C) as your equipment allows. Lager the brew at this temperature undisturbed for six to eight weeks. Then rack, prime and bottle. The rauchbier is ready for drinking after about another week. Serve the beer at around 45 °F (7 °C).