I am using node.js with express. I read out data from MongoDB with Mongoose and deliver it the normal way with `res.send(data)`. Unfortunately the delivering fails for some requests. Even so the header says the encoding is utf-8, it seems to be ANSI in some cases, causing the jsonp callback function to fail with an error.

You can reproduce the error at this page: <http://like-my-style.com/#!single/9837034> . The jsonp call fails just on some products, most of them (also the ones with special chars) work fine.

How can I ensure, that a given String is encoded in utf-8 in node.js?