The Krymchaks (Krymchak: кърымчахлар, , кърымчах, ) are Jewish ethno-religious communities of Crimea derived from Turkic-speaking adherents of Rabbinic Judaism. They have historically lived in close proximity to the Crimean Karaites, who follow Karaite Judaism.
At first krymchak was a Russian descriptive used to differentiate them from their Ashkenazi Jewish coreligionists, as well as other Jewish communities in the former Russian Empire such as the Georgian Jews, but in the second half of the 19th century this name was adopted by the Krymchaks themselves. Before this their self-designation was "Срель балалары" (Srel balalary) – literally "Children of Israel". The Crimean Tatars referred to them as zuluflı çufutlar ("Jews with pe'ot") to distinguish them from the Karaites, who were called zulufsız çufutlar ("Jews without pe'ot").
Krymchak language
The Krymchaks speak a modified form of the Crimean Tatar language, called the Krymchak language. It is the Jewish patois, or ethnolect of Crimean Tatar, which is a Kypchak Turkic language. Before the Russian Revolution in 1917, the Krymchaks were at least bilingual: they spoke the Krymchak ethnolect and at the same time mostly used Hebrew for their religious life and for written communication. The Krymchaks adhered to their Turkic patois up to World War II, but later began to lose their linguistic identity. Now they are making efforts to revive their language. Many of the linguistic characteristics of the Krymchak language could be found in the Crimean Tatar language. In addition, it contains numerous Hebrew and Aramaic loan-words and was traditionally written in Hebrew characters (now it is written in Cyrillic script).
The Krymchaks are likely a result of diverse origins whose ancestors probably included Sephardic and Ashkenazi Jews, and Jews from the Byzantine empire, Genoa, Georgia, and other places.
Other more speculative theories include that the Krymchaks are probably partially descended from Jewish refugees who settled along the Black Sea in ancient times.