America, please stop inspecting your watermelon's butthole.
The so-called "butthole" on a watermelon is simply the blossom end—the spot where it had produced a small, one-inch yellow, star-shaped blossom in late spring & early summer. Although there are male flowers, only the female flowers become watermelons. The flower lasts only a day or two. Pollination is done by bees, triggering pollen tubes that grow into the ovary. Behind the petals, a miniature baby watermelon grows. These tiny green ovaries become the watermelon you buy. The ovary becomes a sink organ—a biological vacuum that pulls resources from the vine. But the fruit does not hang in the air from the vine; it rests on the soil. The vine is an extremely efficient sugar & water pump, capable of inflating the ovary into a massive storage organ—the watermelon. Fertilization triggers cell division & sugar accumulation. The fruit matures in 35-45 days after successful fertilization. The spot where the flower was attached becomes the blossom end scar—the "watermelon butthole."
The fruit is 92% water & about 6% sugar (that's far lower than grapes at 16%). A medium-sized watermelon has the highest sugar concentration, with about 10-18 lbs (4.5-8 kg) being the sweetest variety. The largest watermelon recorded weighed 350.5 lb (159 kg), but this was not at all sweet. They are agricultural contests—not culinary experiences. Examining the watermelon for its so-called butthole does not tell you anything about ripeness or sweetness. The internet invented this selection method, but don't pay any attention to it. Look for the field spot instead. This is a creamy yellow patch on the watermelon where it rested on the ground while ripening. A deep yellow field spot means the melon spent more time on the vine, accumulating more sugars & therefore will be sweeter.
The field spot is the contact patch between the developing watermelon & the soil. Because that side is shaded from the sun, chlorophyll doesn't develop, the rind stays pale, & over time, it turns creamy yellow as carotenoids accumulate. A large deep yellow spot is an indicator that the fruit had a long ripening time to develop into a sweeter fruit. Avoid white or greenish-looking field spots. Many people tap it to check for ripeness. This works because ripe flesh is firm & water-dense, creating a resonant cavity. It should sound deep, hollow & resonant. The melon should be uniform & symmetrical with a firm, matte rind.
