[bomdo]

Impressively, it also works for languages other than English (albeit having trouble with formatting here and there).

Is there a behind-the-scenes somewhere? Is this regex magic alone?

[mstaoru]

There are two open formats for recipes: hRecipe microformat, and Schema.org Recipe entity. Aggregators like Yummly parse those. Most food blogs are based on Wordpress or Typepad, both of which has recipe "editors" as plugins and produce valid hRecipe definitions.