Does commercial barley water, available in grocery stores, contain a percentage of alcohol due to its preservation method, and is consuming it considered a sin?

The default ruling is that it is permissible to use all barley products, unless they reach the point of intoxication on their own or by adding other substances to them. Accordingly, if barley water is intoxicating by its nature or by the addition of alcohol to it, then it is not permissible to use it, sell it, or buy it; due to the Prophet's (peace be upon him) saying: "Every intoxicant is forbidden."