Whether you can ripen a melon after buying it depends entirely on what type of melon you have. Cantaloupes will continue to ripen on your counter, becoming softer and more aromatic over a few days. Honeydew melons and watermelons will not. They’re non-climacteric fruits, meaning once they’re picked from the vine, their sugar content is locked in. Understanding this distinction is the single most useful thing you can learn about ripening melons.
Why Some Melons Ripen and Others Don’t
Fruits fall into two categories based on how they behave after harvest. Climacteric fruits produce a burst of ethylene gas as they ripen, which triggers changes in texture, color, aroma, and sugar content. Cantaloupes (and other muskmelons) are climacteric. They ripen quickly after harvest and have a short shelf life as a result.
Non-climacteric fruits don’t produce significant ethylene after being picked. Watermelons and honeydew melons both fall into this group. Once they’re cut from the vine, they stop developing internal color and won’t increase in sweetness. The sugar that was in them at harvest is all the sugar they’ll ever have. A honeydew might soften slightly on the counter, and its aroma may develop a bit, but the actual sweetness won’t change. If you bought an underripe honeydew or watermelon, there’s no trick that will make it sweeter.
How to Ripen a Cantaloupe at Home
If your cantaloupe is firm and doesn’t smell like much, it needs more time. Place it on the counter at room temperature, stem end down. Most underripe cantaloupes will be ready in one to three days. You’ll know it’s there when the blossom end (the side opposite the stem) smells sweet, floral, and slightly musky. If you can’t smell anything, it needs more time. If it smells boozy or fermented, you’ve waited too long.
To speed things up, place the cantaloupe in a paper bag with a ripe apple or banana. These fruits are high ethylene producers, and the bag traps the gas around the melon, accelerating the ripening process. Don’t use a plastic bag, which holds moisture and encourages mold. Check daily, because cantaloupes can go from perfect to overripe fast.
A few other signs your cantaloupe is ripe: the netting on the skin should feel raised and rough rather than flat and smooth. The stem end should have a clean, slightly indented circle with no stem still attached. If part of the stem is there, the melon was likely cut from the vine before it was ready, which means it may never develop full flavor. Press gently near the stem end. The flesh should give slightly, like a just-ripe avocado. And a ripe cantaloupe will feel heavy for its size, a sign it’s full of juice.
What to Do With Honeydew
Since honeydew won’t sweeten after harvest, your best move is to pick a good one at the store. Look for a consistent creamy yellow color with a touch of gold across the entire rind. Any greenish patches on the skin indicate it was harvested too early. Small brown freckles on the rind are actually a good sign, suggesting higher sugar content.
Give the melon a gentle touch. A ripe honeydew feels slightly waxy or velvety, and at peak ripeness, the skin has a faint stickiness as sugars rise to the surface. Avoid melons with soft spots, bruises, or other damage. Like cantaloupe, a ripe honeydew should feel heavy for its size.
If you bring home a honeydew that’s a little firm, leaving it at room temperature for a day or two can soften the texture and let the aroma develop. But the paper bag trick is less effective here. Honeydew melons don’t produce ethylene and aren’t particularly sensitive to it from other fruits, so placing one next to bananas or apples won’t do much.
Watermelon Can’t Be Ripened Off the Vine
Watermelons are harvested at full maturity because they simply don’t develop further once picked. There is no counter trick, no paper bag method, and no amount of waiting that will improve a bland watermelon. The entire ripening process happens while the fruit is still connected to the plant, drawing sugars from the leaves.
When selecting a watermelon, look at the ground spot, the pale patch where it rested on the soil. It should be a deep, creamy yellow. A white or very light ground spot suggests the melon was picked too soon. The watermelon should also feel heavy for its size and sound hollow when you tap it.
Store whole watermelons between 50 and 60°F with high humidity, and they’ll keep for up to three weeks. At room temperature above 75°F, shelf life drops to about five days. Don’t refrigerate a whole watermelon below 45°F for extended periods. Temperatures between 32 and 45°F can cause chilling injury, leading to pitting, off-flavors, and color loss. Once you cut it, though, refrigerate the pieces and eat them within a few days.
Storage After Ripening
Once any melon is ripe, move it to the refrigerator to slow further softening. A ripe cantaloupe left on the counter will go from perfect to mushy within a day or two. Refrigeration buys you several more days.
One storage detail worth knowing: keep cantaloupes away from ethylene-sensitive produce like lettuce and fresh herbs. Cantaloupes produce ethylene even after harvest, and that gas will wilt nearby greens. Watermelons are the reverse. They don’t produce ethylene but are sensitive to it, so storing a watermelon next to bananas, apples, or cantaloupes will shorten its shelf life.
Wash Before You Cut
Melon rinds can carry bacteria on their surface, and a knife drags whatever is on the outside straight through the flesh. Cantaloupes are especially prone to this because their rough, netted skin gives bacteria more places to hide. Before cutting any melon, scrub the rind with a brush under cool running water. Wash your hands with soap beforehand, and clean your knife and cutting board with hot, soapy water both before and after. Skip melons with visible blemishes or cracks in the rind, which give bacteria a path inside before you even get the fruit home.