How to Cover Half a Watermelon (Does Plastic Foil Work?)

There is hardly anything more delicious or refreshing on a hot summer day than a slice of ruby red and perfectly juicy watermelon. Hydrating and wonderfully sweet, hardly anyone can turn down a bite. The trick with watermelon, though, is that you invariably have some left over unless you are feeding a huge crowd.

Keeping a cut watermelon fresh is a lot harder than it sounds, and people resort to all sorts of methods. Some are more effective than others, and one of the most popular uses it regular aluminum foil. Will covering a cut watermelon with aluminum foil keep it fresh?

Yes, tightly covering a cut watermelon with aluminum foil will help preserve it for a few days. Keeping the foil as tight as possible on the watermelon will ensure success.

half a watermelon covered with plastic shower cap
half a watermelon covered with plastic shower cap

It might not seem like rocket science, and it isn’t, but food preservation is an important skill to master, even when you’re only trying to preserve it for a few days.

So whether you are stashing leftovers or just trying to keep that watermelon fresh after you sneak a bite ahead of your holiday barbecue, it pays to know what works best. we will tell you about several other methods in the rest of this article.

Why Do You Need to Cover a Cut Watermelon?

For anyone who somehow does not already know, fruit goes bad quickly when the flesh is exposed to air. Watermelon in particular has a short, short shelf life and tends to go bad very quickly when cut.

This is because the red flesh of the watermelon is much softer than other fruits, like apples for example, and because it has a far greater water content inside; its in the name after all! These qualities make it more susceptible to being contamination and decay after being cut.

Watermelons will only last for a day at most if uncovered, and their quality usual degrades significantly in several hours.

However, it is possible to keep them fresh and edible for a few days after being cut if you cover them properly and promptly. This is because you are slowing down the process of decay and helping them stay fresh that little bit longer.

The following methods will work just fine for preserving your watermelon.

4 Methods to Cover a Cut Watermelon

Aluminum Foil

Aluminum foil is one of the most popular and reliable methods for preserving a cut watermelon, provided you wrap it tightly. This kitchen staple is impermeable to air, but the shape of the watermelon and comparative rigidity of the foil means you usually won’t get a good seal on the sides, letting air leak in.

This can be remedied by completely and tightly wrapping the whole melon half or using a rubber band to snug it down on the sides.

Also, don’t pay any attention to the old wives’ tale about aluminum degrading the taste of watermelon or accelerating the decay of it: there is no such chemical reaction that takes place, and certainly your usual kitchen-grade aluminum foil is completely safe and suited for the purpose.

If you use aluminum foil to preserve your watermelon, you can expect it to stay fresh for a couple more days, typically.

Plastic Wrap

A common companion or competitor to aluminum foil,  plastic wrap is also a reliable method for preserving watermelon. This alternative has the advantage of being able to cinch down very snug over the surface of the melon, increasing your chances of getting an airtight seal.

The downside is you might need more plastic wrap than foil for this, since you will likely need to completely encircle the melon to secure it. This is only a minor concern since many common plastic kitchen wraps are now cheaper than aluminum foil. 

Like with aluminum foil, seal it tightly and diligently to ensure maximum freshness; if it lifts at the sides or you have a pocket of air trapped under the wrap, you are giving oxygen access to the watermelon flesh and will soon be dealing with a spoiled melon.

Some modern kitchen wrap is designed with a food-safe adhesive quality that will make getting a good, tidy seal a snap. If all you have left is a few larger slices you can use gallon-sized plastic freezer bags to the same effect.

Once again, you can expect a couple of good days worth of freshness when sealing your melon with plastic wrap.

How are you supposed to keep it fresh and free from flies? Here’s the best way to cover half a watermelon (my favorite way, anyways!): Use a shower cap!

It’s free if you can collect them from your hotel stays. And it works perfectly. Plus, they’re reusable!

It’s also super handy for covering a paper plate of food or other dishes that don’t hold plastic wrap well. Problem solved!

I know this sounds absolutely bizarre, but you must hear me out: there is a dedicated contingent of people out there that swear by the shower cap method of preserving watermelon.

The idea is that you take any typical plastic, elastic shower cap and place it over the cut watermelon like an umbrella. This will cover the surface with a waterproof barrier adequately and keep oxygen out, but now with the added benefit of a secure grip on the melon thanks to the elastic band. 

While this isn’t a bad way to do it, it certainly isn’t foolproof either.

While the air won’t get in from the top per se, there can still be areas where oxygen has access around the outside edges of the melon near the band, and getting them to snug down as tightly as normal plastic wrap or aluminum is challenging thanks to their crinkly shape.

Despite this, the low cost and sheet convenience of the shower cap method has won many fans, especially for short term storage like hauling leftovers home from a party or picnic. Expect to get an extra day, perhaps two from your cut watermelon when stored this way.

Lidded Food Container

One of the most obvious methods today for storing food of any kind is the classic food storage container, conveniently sealed tight with a mating lid.

This is also one of the best methods for preserving the freshness of your cut watermelon; most will provide an absolutely airtight seal and keep out any contaminants that might be in the air or on the countertop. 

The downside is, you have to have an appropriately sized airtight container handy in order to use this method; if you have a large watermelon, even when it is cut in half it will be far, far too big for almost any common container and that is why you see so many people trying to jury-rig them in a mixing bowl for the purpose.

But if you want to cut the melon up into wedges or slices, or even into cubes ditching the rind entirely, you’ll have a much easier time keeping them in containers of common size. Stored appropriately, a sealed container will give your watermelon a few more days of freshness.

Other Watermelon Storage Tips

Here are some other tips and tricks for getting the most out of your leftover watermelon, no matter what method you want to use.

Keep whole fruit at room temp:  While the refrigerator is great for preserving freshness, if your watermelon is still whole you should keep it at room temperature. This will give you the longest shelf-life and best flavor.

Refrigerate cut melon: If your melon is already cut, whether or not it is cubed or sliced, then storing in a covered container in the fridge is absolutely essential to prolonging life. 

Keep the moisture in: Melons are a juicy, succulent fruit so protecting it from drying out is also important. Make sure your sealed containers and wraps are well-tucked and the melon placed properly to avoid letting that sweet juice run out. 

Keep it out of direct sunlight: Watermelons need sunlight to grow when on the vine, but after they are harvested it is not going to do them any favors and will accelerate decay. Keep your cut melon especially out of the sun!

Freeze it!: Yes, it is possible to freeze watermelon without ruining it, believe it or not.

Simply cut it into slices, discs or wedges no more than an inch thick and lay them out in a single layer on a baking sheet lined with wax paper or parchment paper then stick ’em in the freezer until you need them! Keeps for at least half a year.

Note that the texture of the flesh will be even softer than usual when you thaw it, but still good and tasty. Frozen melon is perfect for smoothies, too! Just for clarity, never try to freeze a whole watermelon.

6 thoughts on “How to Cover Half a Watermelon (Does Plastic Foil Work?)”

  1. I take watermelon off the Rhine and cut into small pieces
    and put it in cheap plastic bags takes up less room in the refrigerator

  2. Great idea – but I would worry about the plastic not being food-grade. If it is something that concerns you, a sheet of plastic wrap could be placed underneath the shower cap.

  3. This is a brilliant idea! It’s one of those “Why didn’t I think of that?” ideas! hahaha… I’m totally gonna remember to save those shower caps that I ” most def. PAY” for and usually leave in my hotel rooms because I always think…I don’t need to collect more junk. But I will now put these babies to good use! 🙂

  4. It is something you would have to buy, but once you buy it is reusable, but Glad (and probably some other brands and non-brands) make different size dish covers that are basically just different size shower caps. I bought a bag of several different sizes and use them to cover any dish that doesn’t have a lid. They are great! I think you find them in the same aisle as plastic wrap and aluminum foil.

  5. I wish I had thought of this when we were actually staying in hotels. Oh well. Maybe a cheap shower cap or two from a Dollar store will work as well. Thank you! What a great idea. :o)


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