https://www.homebrewersassociation.org/homebrew-recipe/pickelhaube-marzen/
Original Gravity: 1.056
Final Gravity: 1.010
ABV: 6%
IBU: 23.5
SRM: 10
To brew the Pickelhaube Märzen, mash in for a protein rest at 122°F (50°C) for 20 minutes. Pull your first decoction of about 9 quarts (9 L) and boil for 15 minutes. Add back to main mash and equalize at 150°F (66°C). Hold at that temperature for 60 minutes. Apply heat or boiling water to mash out at 168°F (76°C) for 10 minutes.
Sparge, boil 90 minutes, and add hops at stated intervals.
Chill and oxygenate when wort temperature falls below 80°F (27°C). Pitch a strong starter of yeast at 48°F (9°C).
Fermentation temperature may be allowed to rise to 50°F (10°C). As fermentation slows, bring to 55°F (13°C) and hold three days for a diacetyl rest.
When the gravity reaches 1.012 (3°P), crash to lager temperatures (35°F or 2°C) and lager the beer for two to three months or until Oktoberfest.