1. How it looks matters a lot
When choosing a watermelon, pay attention to how it looks. What you want is a hard, symmetrical watermelon that has no cracks, dents or soft parts on the rind.
Even if there’s slight damage to the exterior, don’t buy it because no matter what the nature of the damage, it’s always transferred inside. These irregularities normally appear during the growth period as a result of water deficiency or excessive exposure to sun.
A ripe watermelon comprises 92% water and 6% sugar, which means that the watermelon should float on the surface if soaked in a bucket of water. As you probably won’t have a bucket of water when you go to the market, it’s best to compare the weights of two watermelons of quite the same size. The one that’s heavier, it’s sweeter.
3. Check the yellow area on the watermelon rind
The yellow area on the rind shows where the watermelon rested on the ground while ripening in the sun. If this place is darker shade of yellow, it means that the watermelon has ripened properly. If it is pale or doesn’t even exist, it means that the watermelon was picked too early.
The perfect ripe watermelon is dark green and matte. Shinier watermelons are usually less lenient.
Last, but not least, you can use the ‘knocking’ method to check if the watermelon is ripe or not. What you should focus on is the sound produced. An unripe watermelon gives a deeper tone than a ripe one.