Ruby on Rails中的局部变量未定义

我目前正在youtube上关注食谱框教程。当我打开Rails控制台并键入

@recipe = current_user.recipes.build

我收到以下错误：

NameError: undefined local variable or method `current_user' for main:Object
from (irb):3
from /Users/matthiascordes/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/console.rb:65:in `start'
from /Users/matthiascordes/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/console_helper.rb:9:in `start'
from /Users/matthiascordes/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:78:in `console'
from /Users/matthiascordes/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
from /Users/matthiascordes/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in `<top (required)>'
from bin/rails:9:in `require'
from bin/rails:9:in `<main>'

是否有人知道哪里出了问题以及如何解决这个问题？我正在将devise gem用于我的用户模型。