Older German blog posts will be translated. Recently I have started posting both in German and in English, but there is still more work for me to do. The good news for you: all existing posts will be translated into English sooner or later.
We use the poylang WordPress plugin to organize translations. While this works well from German to English, somehow the language switcher from English back to German does not show up all of the time, which might or might not be a bug in the plugin. We will try to fix that as well.