I've been asked that by a couple of people. It is not known as a beer city. In fact, the bulk of the ride is thru the former East Germany (DDR) and in German terms is a bit of a beer wasteland. At least compared to Bamberg and Oberfranken.
It's a bit convoluted but I don't pay (or get paid) by the word so here goes...
About 5-6 years ago I had a tooth pulled and a dental implant, well, implanted. I wasn't really happy with the high pressure sale the dentist did (since switched dentists) so I went online and did some searches. One site that came up was a dentist in Rostock that had a deal if you needed a mouthful of implants. It required you spend a lot of time in Rostock and so he had a description of the town (obviously in its best light). It sounded a bit like Bamberg, without the breweries.
I didn't need a mouthful of dental implants so I moved on.
Fast forward to last year, when I was trying to decide what bike tour to do in 2014. It is the year I turn 60 so I was looking for something interesting. I considered riding down the Rhine from Basel, or riding around Lake Constance and then down the German part of the Danube. Then I came across a mention of a Berlin to Copenhagen bike trail. Research showed that you rode to Rostock and then took a ferry across the Baltic and then thru Denmark to Copenhagen. Perfect -- I could visit Berlin, which has vastly improved, Beer-wise since my last visit (or so I've been told) and I have been wanting to go back to Copenhagen. Plus, I get to see Rostock.
Then my youngest brother -- who in his youth was an avid cyclist, said he'd like to come. He also has a Bike Friday New World Tourist (but with an 8-speed rear hub) and while he had some some long distance rides (like RAGBRAI) they were all fully supported and he had never done any kind of self supported tour. He also has never been to Bamberg in the summer time, only a few trips in the fall.
We were all set when the real world intruded. He has a real "day job" -- unlike me who is a lazy freelancer -- and also three kids (the youngest just graduated from Hight School). It ended up that he just didn't have the time to go all the way to Copenhagen. So we added a few days on the front end (Jena to Leipzig to Berlin) and decided to stop at Rostock.
So that is why the tour ends in Rostock. Oh, and there was a fare sale on Delta earlier this year so I managed to get a really cheap ticket to Copenhagen in September. so I will get to do that part, sans bicycle.
And one final irony -- last week I started having problems with the crown on the implant. I went to my new dentist and she said it will have to be replaced when I get back. Unless I can find that Rostock dentist.