A new generation of designer solvents emerged in the last decade as promising green media for multiple applications, including separation processes: the low‐transition‐temperature mixtures (LTTMs). They can be prepared by mixing natural high‐melting‐point starting materials, which form a liquid by hydrogen‐bond interactions. Among them, deep‐eutectic solvents (DESs) were presented as promising alternatives to conventional ionic liquids (ILs). Some limitations of ILs are overcome by LTTMs, which are cheap and easy to prepare from natural and readily available starting materials, biodegradable, and renewable. Liquefaction: LTTMs are promising “green” media for multiple applications, including separation processes. They can be formed by mixing high‐melting‐point starting materials, which form a liquid as a result of hydrogen‐bond interactions (see picture). Among LTTMs, deep‐eutectic solvents (DESs) are presented as renewable, biodegradable, and cost‐effective alternatives to conventional ionic liquids (ILs).