I visit Germany 1-2 times a year, and my friend always makes me go to the alte haus. I have been…read morecoming here for over a decade, often during the local Apple Wine festival.
I notice the German reviews are all 4-star, in lock-step. Maybe I'm influenced by the fact I've been attending so long, but I love it.
The food is simple German standbyes - giant knobs of pork, potatoes, dumpling, schnitzel, and so forth. Done well, and unpretentiously.
They serve a lot of local specialties which are hard to find, such as frankfurt green sauce (made fresh from 12 different herbs), and handkaese mit musik, which is not for the faint-hearted .
The building is in the amazing old town of Dreieich, and is centuries-old. No AC of course, as is standard in Europe. :(
Staff does not speak English well, so go with a German if possible. On an early visit, I asked the waitress for their "best dish" and she misinterpreted "largest dish". I got a boulder of pork shoulder so big it had a flag on top. A companion dubbed it the "fleischberg"!
Portions are gigantic, so beware if you can't take leftovers home. My dad ordered wiener schnitzel and got TWO enormous schnitzels, a raft of potatoes, and a hillock of red cabbage. He was daunted.
I know people like to say we Americans eat huge portions, but the alte haus beats us all hollow.