Allow pomelos to ripen on the tree if you are growing them yourself. Leave the fruit in place as long as possible before harvesting. The trees may flower and fruit more than once per year, but the main crop of fruit begins to ripen on the trees around November. The rind yellows as the fruit ripens.
Place the fresh-picked pomelos in a dry, well-ventilated spot in the home or garage where they will not freeze. Store the fruit for up to three months. As the fruits age, the rind will become wrinkled and deeper yellow, but the fruit inside will be sweeter and juicier than fresh-picked fruit. Hang the fruits in individual mesh bags, if desired.
Look for thinner, shiny rinds and fruit that seems heavy for its size when buying pomelos at the supermarket. Store the fruit in the refrigerator or in a dry, well-ventilated spot in the home or garage for one to two weeks to allow the fruit to age and sweeten.