High Quality Content by WIKIPEDIA articles! Yoghurt, yogurt or yogourt (UK: /j?g?t/, US: /jo?g?rt/, Turkish: yogurt, pronounced ) is a dairy product produced by bacterial fermentation of milk. The bacteria used to make yoghurt are known as yoghurt cultures. Fermentation of lactose by these bacteria produces lactic acid, which acts on milk protein to give yoghurt its texture and its characteristic tang.