https://www.homebrewersassociation.org/homebrew-recipe/old-helen-helles-exportbier/
Single infusion mash at 152°F (66.7°C) for 60 minutes. Mash out at 168°F (75.6°C). Lauter, add first wort hops, and bring to a boil. Boil 90 minutes, adding hops as indicated. Chill to 50°F (10°C), pitch yeast, and oxygenate 1 minute. Hold temperature at 50°F (10°C) for 5 days and slowly ramp to 65°F (18.3°C) over 4–6 days. Hold at 65°F (18.3°C) until fermentation is complete, then begin to slowly chill beer to the mid 40s °F (6–8°C) or colder. Rack to a keg and carbonate to 2.5 vol. (5 g/L) CO2.
Pro tip: Serve young as a hazy Kellerbier, and after a month of lagering in the keg, the beer will mature into a clear Dortmunder. Serve in a 2 L boot, preferably
Garrett Notes:
Original recipe called for 1.2oz magnum at 60min, this appears incorrect. It looks like it should be 0.5oz at 60min to hit the target IBUs. (Under the original scaled 10gal, the recipe has been scaled to 12gal since.)