The type only matter locally and in RecipeIterator class which I've edited.
The field is also used in CraftServer but it only uses clear() and re-asigns it (on clearRecipes() and resetRecipes() methods).

It would break server mods and plugins that directly use that field (which for plugins is unsupported anyway)... should I change the Map and getRecipe()'s  types so other classes know what types it uses ?