This paper introduces the difficult relation between language, ethnicity and individual identity of the German population living in Siberia today. In 2010, we interviewed four women born in the former German Volga Republic but now living in a village in Siberia. Their German language and identity were strongly stigmatized as a result of the Second World War. Today they primarily speak Russian in their everyday communication. Nevertheless, the women’s ethnic identity is still very strong, - they call themselves “daitsch” (Germans). In the linguistic analysis, which can be seen as pioneer work for German in Siberia, we identified a large proportion of language contact phenomena such as code switching to Russian and contact-induced structural changes in this spoken German variety. The paper focuses on the essential role of the “mother tongue” that seems to elicit ethnic identity.