Summary: We exhibit a non-finitary sentential logic that is algebraized by a quasivariety -- in fact by a finitely based variety of finite type. The algebraization process requires infinitely many defining equations. The existence of such a logic settles a question posed by \textit{J. Czelakowski} [Protoalgebraic logics. Dordrecht: Kluwer (2001; Zbl 0984.03002)] and implicitly by \textit{B. Herrmann} [Stud. Log. 57, No.~2--3, 419--436 (1996; Zbl 0864.03043)].