Pomelo fruit has a nice citrus taste, quite sweet, but at the same time with a hint of grapefruit's bitterness, that is less intense if you eat the fruit's flesh segments after peeling off a thin rind around them. The fruit itself is covered with thick skin, which makes it look huge.
The difference between a ripe and a green pomelo is its weight. You might feel this huge fruit and find out that it is light and it means pomelo still has to ripen, whereas mature pomelos are rather heavy, as they are full of vitamin liquid.
Pomelo fruit is a good anti-oxidant and supplier of vitamins C and A, calcium, iron, dietary fibers and potassium. In Singapore, it is harvested in August and September and is plentiful at the Mid-Autumn Festival.