New Organic Ume Su Plum Seasoning. Due to the challenge of sourcing organic shiso leaves this recipe is made just with ume plums and sea salt. This tart, tangy seasoning is the juice resulting from the pickling of Umeboshi, the Japanese everyday staple salt pickled plums. A very versatile condiment that adds a refreshing zest to salad dressings, cooked vegetables and marinades. Use like vinegar, but due to its inherent saltiness, any salt in a recipe may need to be reduced.