new_contents: # -*- coding: utf-8 -*-
  
  from .sugar import sg_to_gu
  
  __all__ = [
      u'calculate_brew_house_yield',
  ]
  
  
  def calculate_brew_house_yield(wort_volume, sg, grain_additions):
  
      gravity_units = 0.0
      for grain_add in grain_additions:
          gravity_units += grain_add.grain.ppg * grain_add.weight
      return sg_to_gu(sg) * wort_volume / gravity_units
  
subject: Add a brew house yield calculator