The two kinds of fruits are not crushed and the high fiber is not filtered, so it is a pure cellulose drink, not a juice.
Grapefruit is peeled off, and a piece of pure grapefruit is cut out.
Cut the apple pieces, put the grapefruit meat into the blender and pour a cup of pure water. I use the most common hexagonal glass of IKEA about 300ml.
All made into mud. The thick flesh cellulose is very full, sour and sweet, don't add any sugar.