When people ask, are you a yekke (and I get asked this often enough) they generally mean, I believe, do your parents or grandparents come from Germany? And I suppose the strict definition of a yekke is a Jew from Germany or a Jew with traceable lineage to Germany as parents from places like England, South Africa, the USA, Holland, or Switzerland (countries to which German Jews immigrated over the last 100 years) with known ancestors from Germany, Prussia, or Austria also seem to qualify. The term yekke is of uncertain origin. It might be a reference to short coats or Jacke in German as German Jews of the last few centuries tended to wear shorter jackets than their brothers out East.
So you might wonder then what is an Ashkenazi Jew as you certainly know of Ashkenazi Jews from places like the Ukraine and Poland. The name derives from the biblical figure Ashkenaz, the first son of Gomer, the eldest son of Japeth, a son of Noah. For reasons which are much debated, this name became attached to the mass of Jews who made their way through Italy and into Central Europe in the centuries after the destruction of the second Temple. Another set of Jews, which we now call Sephardim, made their way to Babylon and then North Africa and eventually Spain. In the words of the Jewish Virtual Library, "The name Ashkenaz was applied in the Middle Ages to Jews living along the Rhine River in northern France and western Germany." Many of these people migrated East and by the 16th century, the center of Ashkenazi Jewry was located in Poland, Lithuania, Bohemia and Moravia and soon after in Russia, the Ukraine, and the Baltic states. They all are Ashkenazim, decendents of the Jews who lived along the Rhine River. Their shared lineage is evidenced in the language Yiddish which is an offshoot of German. As R' Shlomo Hamburger, an expert on German Jewish customs, points out, the Yiddish word for translate - titsche - comes from the word Deutsch or German. So imagine a conversation where two people are chatting away in Italian and you can't follow it. You want them to switch to English so you shout "English!" Centuries ago one of your ancestors, if you are Ashkenazi, might have shouted, "Deutsch!" or "German!"
So you might ask, are they yekkes too? Well it gets complicated due to the rise of the Chassidic movement in the 18th century as a large portion of Ashkenazic Jewry took on a new set of customs, called Sefard, some of which developed under the new conditions of Eastern Europe and some of which were taken from Sephardic liturgy and kabbalah. Technically, these people are Ashkenazim, but we wouldn't call them German Jews or yekkes, even though originally their ancestors were from Germany. There also are Eastern European Jews such as those from Lithuania, who didn't take on nusach Sefard, yet don't call them German either. They are Litvacks and their practice is much closer to that of German Jews with many significant differences.
Interestingly, the USA currently is home to more Ashkenazi Jews than any other country in the world. Here's a chart from Wikipedia:
|Regions with significant populations|
|United States||5–6 million|
|State of Israel||2.8 million|
|United Kingdom||~ 260,000|
So that's what I'll say for now about the German Jews. Torah Im Derech Eretz came out of Germany. It's the work of Rabbi Hirsch but he designed it for Germany utilizing the traditions from his German Jewish rebbes. A person need not take on German Jewish custom or identity to gain from Torah Im Derech Eretz as the philosophy is useful to the modern, western dominated world in general.