Sourdough starter

I have a Sourdough Starter which I made some time ago using an organic apple, cored but not peeled and then grated, along with some white bread flour and water. At first, it worked really well, making my bread rise nicely, but now it's not so good and I don't know why.

However, a week or so ago I saw a video clip on YouTube from a guy in Birmingham, England, who made his sourdough starter only from organic rye flour. I have followed his recipe and the starter is now 5 days old. This morning, when I came to look at it, it had a bloom (I think it's called) on the top, see picture below.

   I hope you can see what I mean from this image.

What I want to know is, is this how it should look? It has a yeasty smell about it and I think slightly vinegary, but my wife doesn't think it is vinegary.  If this is as it should be, I will just keep feeding it as instructed. But if it is not OK, presumably I should start again, but what has happened to make it go like this?

Any advice would be most welcome.

Thanks in advance. handymanchef