Redirect from www.* to your apex domain. Or from your apex domain to a www. subdomain.

routes-www.rb

Brewhouse::Application.routes.draw do
  constraints(host: /^(?!www\.)/i) do
    match '(*any)' => redirect { |params, request|
      URI.parse(request.url).tap { |uri| uri.host = "www.#{uri.host}" }.to_s
    }
  end

  resource :drink_up, only: [:show]

  root :to => redirect('/drink_up')
end

routes.rb

Brewhouse::Application.routes.draw do
  constraints(host: /^www\./i) do
    match '(*any)' => redirect { |params, request|
      URI.parse(request.url).tap { |uri| uri.host.sub!(/^www\./i, '') }.to_s
    }
  end

  resource :drink_up, only: [:show]

  root :to => redirect('/drink_up')
end

via: :all should be appended to match since Rails 4.