Abstract: In a process and apparatus for the production of carboxylic acid esters, a liquid carboxylic acid stream is fed to an upper section of a reaction zone maintained under esterification conditions. An alcohol vapour stream is fed to a lower section of the reaction zone; allowing the carboxylic acid stream to pass in countercurrent to the alcohol stream to form a liquid product stream of product ester. A refiner stream is withdrawn from at or near the top of the reaction zone and includes unreacted alcohol, water and ether by-product. The refiner stream is passed to a refining zone and treated to reduce the water content thereof to form an ether-containing stream having a water content that is lower than that of the upper stream removed from the reaction zone. This ether-containing stream is recycled to the reaction zone.