compass_config.rb

if environment == :production
  on_stylesheet_saved do |file|
    # pretty logging output when making a gzipp'ed file
    gz_file = Pathname.new("#{file}.gz").relative_path_from(Pathname.new(project_path))
    Compass::Logger.new.record(:create, gz_file)
    # This generates a file of the same name but ending in .gz
    `gzip -f #{file}`
  end
end

If you'd like to keep the original .css files along with the .gzip files, use the -k argument for gzip:

if environment == :production
on_stylesheet_saved do |file|
# pretty logging output when making a gzipp'ed file
gz_file = Pathname.new("#{file}.gz").relative_path_from(Pathname.new(project_path))
Compass::Logger.new.record(:create, gz_file)
# This generates a file of the same name but ending in .gz
gzip -fk #{file}
end
end