Plums are a tricky fruit to get right. At the moment we are entering the last phase of supply from South Africa and Chile, with varieties from mid to late season. This is usually good news for flavour and sweetness: look out for FlavorKing, the most tasty; then African Delight the most common variety in retailers and Laetitia, both of which are generally very good when properly ripened. The first Angelino (from South Africa & Chile) have been spotted in Aldi and Tesco: normally the last variety of the season, with dense, almost crisp flesh.
Finding the Tastiest Fruit in UK