"Lewis Walden tasted the fruit, and he named the cross Raspberry Tangor (RT) since the fruit was red inside and had a slight raspberry favor. The tree produces a fruit, shaped like its mother the Umatilla that ripens in February or March, and it, too, has monoembyronic seeds. Chris Kneupper and JoAnn Trial did an acid and sugar test on the fruit and calculated an acid to sugar ratio. They found that the RT has about 11.6% sugar, but it never loses its acidity of about 2.2% citric acid. When you ratio the sugar to acid, you get about 5.2, and this falls in the category that one finds in mild lemons and grapefruits." - John Panzarella