Over all the years that I've come and gone, and come yet again to Germany....I have continued to attempt to eat German-style hamburgers (I'm not talking about Micky D's or the Whopper King). I'm referring to just regular imbiss-style shops.
For an American, it's just about impossible to find some German imbiss which close to the American-style that you might be used to. The bun will be slightly different. The guy will use some sweet pickle. The kid will put hot peppers on the burger without saying anything. The gal will serve you a burger that is fifty-percent beef and fifty-percent of some mystery substance. Or the guy will use some weird mustard and ketchup mixture that is loaded with sugar.
Two years ago, I came to this one shop in the Wiesbaden region that came almost close to perfection with their burger. I'll admit....it's a gourmet burger shop and you end up paying a hefty amount for the dish (figure 11 Euro for a full-up burger and fries plate).
It's not really rocket science to cook up a burger. You need quality meat (something without filler), some decent bun (toasted), real mustard (not that French-sweet stuff), sour pickles, wholesome onions carved thin, and a really thin tomato. That's it.
The three worst burgers that I've had while in Europe? 1. At some French autobahn rest-stop, they offered up a burger plate. If you've never been to France.....you need to emphasize WELL-DONE....otherwise, it comes out cooked half-raw and blood dripping off the bun. Yeah, that a lesson upon me. 2. I sat at some diner in the Frankfurt area in 1979 that offered up a burger on a brotchen (the typical German bread), with some sweet pickles, sweet mustard, and sweet mayonnaise. It was the first burger that I ever had one bite out of, and decided to throw it away. 3. In the 1990s at some K-town carnival....I had some burger that was loaded with some mystery sauce (about 30 seconds into this, I came to note that it was jalapeno within the secret sauce), and with each additional bit....I needed a quarter cup of soda....eventually going through two additional sodas to down the entire burger.
American and German McDonald's burgers? If you put both out in front of me.....I don't think anyone can tell a difference. Occasionally, the Germans will run some special with some seasonal additive. A double-burger deal with some weird sauce that would not interest Americans. But there is not basic difference in the way that a typical McDonalds would serve it.
My general advice to Americans coming over to Germany? Skip experimenting with German burgers, and just stick with brats and various German dishes. If someone does come offering some tangy sauce or some hot sauce deal.....you might want to ask what's in it and have some liquid refreshment ready to cool off your mouth.