A retort system includes a vessel defining a heating chamber and including a product receiving area therein, and a product agitating arm mounted for reciprocating movement through a wall of the vessel and having a first end within the vessel and a second end outside the vessel. A drive arrangement is located exterior of the vessel and operatively coupled to the arm for moving the arm in a reciprocating manner. The drive arrangement includes a crankshaft assembly, a first flywheel and a second flywheel. The crankshaft assembly includes a crank throw operatively coupled to the arm, the crankshaft assembly having a rotational axis offset from the crank throw. The first flywheel is mounted to the crankshaft assembly to a first side of the crank throw for rotation with the crankshaft assembly about the rotational axis. The second flywheel is mounted to the crankshaft assembly to a second side of the crank throw for rotation with the crankshaft assembly about the rotational axis.
