Basch was born in 1929 in Tacovo, modern day Tachiv, in the Carpathian Mountains which were then in the most easterly part of Czechoslovakia. In 1941 there were 2,150 Jews living in Tacovo.
Basch’s parents were Mendel and Blanka. He had two siblings, his twin Frieda (b. 1929) and his younger sister Ruzena (b. 1930). It is unknown if these were his only siblings.
There is little information about Basch’s childhood other than that he was part of an ultra-orthodox family.