Rich snippets provide site owner’s additional way to communicate with search engines and shows additional information in the search results. This is not only for reviews or recipes but also for events, products, people, video, music, apps, article and blog posts. In adding Rich Snippets in WordPress using a plugin, you need to installs and activate first the All In One Schema.org Rich Snippets plugin. On the activation simply click on the Rich Snippets menu icon in the sidebar to continue. You can see different content types that consist of Item review, events, person, product, recipe, softwareApp, video and article. Choose any content type that will show you the field that will be available when a user is writing a post/page or any custom post type. Then create a new post or edit an existing one and below the post editor, you will able to see a new meta box labelled Configure Rich Snippet. Inside, you will see a drop down menu where you can select content type for the post you are working on. Selecting a content type will display the rich snippet field you need to fill. Note that you are not required to add all fields but some of the fields are required by Google to display rich snippets and save your post to store the rich snippets data.
If you want to manually add Rich Snippets in WordPress, kindly check the three different vocabularies at Beginner’s Guide: How to Use Rich Snippets in WordPress.