Whenever you travel through Germany and stay in a hotel, I strongly recommend, you add the option to have breakfast there. The added price is reasonable, especially given the great variety of foods you can sample at their buffet.
The ingredients of the buffet vary by region. You find commonalities and each region adds their local type of bread, pastries, cheese, sausage and other cold-cuts. Fruit & veggies vary by season.

Those german buffets put the breakfasts you get at a typical hotel in the US to shame. They dare to call them "Continental Breakfast".

In contrast, the breakfast Lufthansa served after the long flight before arriving at SFO was an utter disappointment. It was a decidedly "german" breakfast with dark, multi-grain bread instead of bland white toast common in the US.
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This page has a very fitting description of a typical german breakfast at home.
"How Germans Eat" : en.bab.la/germany/eating-germany

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