Have you ever had a watermelon split open, or even randomly explode? It’s a relatively rare occurrence, but it’s definitely up there as one of the more surreal food incidents you might experience – so why does it happen?
A watermelon that splits usually does so because of fermentation inside the fruit, or a bacterial infection. Some heirloom types of watermelon are far more prone to exploding because of a gene that the plant carries. Occasionally, watermelons will split as a result of being overwatered, or because of intense heat in their growing environment.
We’ll be using this article to look at and understand the main reasons that watermelons explode. Wonder no more about this strange phenomenon!
What Causes Watermelons To Explode?
Perhaps surprisingly, there is more than one cause for an exploding watermelon, and it may not be instantly obvious what has gone wrong. Before we start looking at those, it’s worth noting that not many watermelons explode, especially once they have been removed from the plant. It certainly happens, but not with great frequency.
So, what are the usual causes? Any of the following may result in this happening:
- The fruit is fermenting
- There’s a bacterial infection
- It’s an heirloom variety
- The fruit was overwatered
- The growing environment is too hot.
That’s quite a diverse set of reasons, so let’s check them out in more detail.
1) The Fruit Is Fermenting
This will usually only happen if the watermelon has been damaged in some way. Usually, the tough skin of a watermelon keeps fungal infections out, and the insides of the watermelon cannot ferment. However, if there’s a small hole or other damage to the rind, the inside of the watermelon will begin to ferment.
How it ferments will make a difference to what happens, but the fermentation process will produce carbon dioxide gas. When it does, this gas tends to build up inside the rind, causing pressure on the outside of the rind. If the gas can’t escape, or can’t escape quickly enough, the watermelon is likely to split open – sometimes at speed.
This results in an explosion of watermelon all over your kitchen!
2) There’s A Bacterial Infection
As well as causing the watermelon to ferment, a bacterial infection can affect the rind and cause it to split open. This is sometimes known as bacterial blotch disease. If this cracks the fruit open, other bacteria and fungi can get into the watermelon (increasing the risk of fermentation), and the fruit may explode.
There’s a lot of fluid in a watermelon, and this can cause the explosion to be violent when it occurs because there’s a lot more pressure on the rind than in some other fruits.
3) It’s An Heirloom Variety
You might have heard that exploding watermelons occur due to a gene. This is true to an extent. Many heirloom watermelons have a gene that causes the rind to split open when it gets bumped or cut. This is a way for the plant to release its seeds, so it’s a survival tactic – but when you plan to eat the watermelon, it can be a dramatic outcome.
The rind of the fruit will burst suddenly open when you try to cut the watermelon, or if you knock it. More modern varieties of watermelon do not have this gene, and so are not likely to explode for this reason (but can explode for other reasons).
4) The Fruit Was Overwatered
Getting too much water while growing can also cause a watermelon to split or explode. This can occur if it’s subjected to heavy rain or grown in soil that does not drain properly. Essentially, the plant absorbs too much water too quickly and puts this water into its fruits. It’s especially common if the water follows a period of drought because drought causes the skin to harden.
When the water is then added, the fruit swells, but the outside of the fruit (the rind) is tough, and cannot expand much. It splits under the pressure of the water, and the watermelon bursts open, spilling juice and flesh everywhere.
5) The Growing Environment Is Too Hot
Too much heat can also cause watermelons to split. Being exposed to warmth will cause the pressure of the water to rise, and this again causes the fruit to expand, sometimes more than the rind can handle.
The rind will split and the watermelon will explode. Varieties with thin rinds are particularly prone to these problems.
Conclusion
As you can see, there are quite a few reasons that your watermelon might explode, and some of them relate to growing conditions. Others are determined by the variety of watermelon you have, or by whether the fruit has been damaged at any point, which would increase the chances of it fermenting.
