Grapes are one of the most succulent and sweetest fruits available at the store. Popping a juicy green grape into your mouth is an absolute delight!
But have you ever noticed that some grapes seem to have a white film on the surface?
So, what is the white stuff on grapes, and can you eat it? The white film on grapes is a waxy residue that is naturally produced by the fruit to retain moisture. It is fine to eat the white stuff, but you should still wash grapes before consumption to remove any residue of chemicals such as pesticides or fungicides.
Want to be sure that your grapes are in tip-top condition and ready to eat?
Keep reading to find out everything you need to know about the white film on grapes, including whether you should remove it.
What Is The White Stuff On Grapes?
Cut into a grape and you will reveal a delicious juicy flesh, that glistens in the light. But turn it over, and you might notice that the skin is covered in a white residue.
Many people panic when they see this, thinking that it means that their grapes are covered in chemicals such as pesticides. But is this true?
While you’re quite right to be concerned about pesticide residue on our fruits and vegetables, luckily in this case, the white film on grapes has nothing to do with chemicals that aren’t safe for consumption!
Now, we’re not saying that grapes are free from chemicals. Unless you’ve bought organic grapes, they will undoubtedly have been treated with pesticides or fungicides at some point.
But even organic grapes can develop a white film on the surface of the skin, so we can be sure that this is nothing to do with chemicals. Phew!
So, what exactly is the white stuff on grapes? Let’s find out!
Why Do Some Grapes Have A White Film?
Interestingly, the white stuff on grapes is actually made up of three different substances. One of these is produced by the grapevine itself, while the others occur as a result of this.
When grapes are growing and ripening on the vine, the plant produces a wax that covers the surface of the grape. This wax forms a coating on the grape skin, preventing moisture from being lost.
As grapes normally grow in warm climates, this is essential to stop our grapes from becoming dry and withered. This is nature’s incredible way of keeping the grapes juicy and plump as they develop – clever stuff!
The wax itself is not particularly visible, but as it forms on the skin of the grape it is slightly sticky.
This leads us to the second component of the white film on grapes, dust.
While we meticulously clean dust from our homes and offices, out in nature there is dust absolutely everywhere! Any fine particle that is light enough to be blown around in the air has the potential to adhere to the sticky wax on the surface of grapes.
And while we’re talking about things that can be blown around, the third component of the white film on grapes is also airborne, and is a living particle!
Yeasts can be blown along on the breeze and will stick to the waxy residue produced by the grape.
The type of yeast that colonizes grapes seems to live in the air around grapes. It is perfectly natural for the surface of fruits to be covered in yeasts. In fact, this is how the process of making alcohol first came about!
Grapes contain the perfect combination of factors needed to make wine – fruit juice, natural sugars, and yeast.
When combined, the yeasts will ferment the sugar and turn it into alcohol. While modern processes are somewhat more complex than this, the humble grape is where it all began!
Can You Eat The White Stuff On Grapes?
So, we now know that the white film on grapes consists of natural substances combined: wax produced by the grape, and airborne dust and yeasts.
In this form, the white stuff on grapes is completely harmless and is safe to eat. If you’ve got a punnet of organic grapes, it is quite likely that the white stuff on grapes can be consumed without causing you any problems.
Unfortunately, modern-day farming practices mean that there tend to be a lot of chemicals used in the process of growing grapes.
And while all of these chemicals are licensed and certified as safe for human consumption, many people try to limit their exposure to them as much as possible.
It is not beyond the realms of probability that some residue of pesticides and fungicides will occur within the white film on grapes.
So, while the pure cloudy residue itself is not harmful to humans, it may well have been contaminated with chemical residue anyway.
Organic grapes are grown with very minimal use of chemicals, and the white film on organic grapes is much less likely to contain any residues of pesticides or fungicides than conventionally grown grapes.
Should You Wash The White Stuff Off Grapes?
While the white stuff on grapes is completely harmless by itself, it is still a good idea to wash grapes before you consume them in case it has been coated with pesticides or chemical residue.
Grapes are known as one of the ‘dirty dozen.’ This is because the outer surface of grapes can be contaminated with residues of chemicals used to control pests while the grapes were being grown.
Food safety advisors recommend you either wash or peel all fruits and vegetables before consumption. This reduces your exposure to agricultural chemicals.
Washing fruit is also a good way to ensure it is free from any bacterial contamination that may have occurred during its transit from farm to grocery store.
When you wash grapes, don’t be surprised if the white residue remains after the grapes have dried. This is because the white film on grapes consists partly of wax, which is notoriously hard to remove.
Just remember that this wax is not only completely harmless, it is actually an essential part of the process of growing juicy, delicious grapes.
So, give your grapes a quick wash before you eat them, and enjoy!
How To Wash Grapes
Is a quick rinse with water sufficient to clean grapes before you eat them, or is something more intensive required?
Many people have been washing grapes in water for years. And this method does remove the vast majority of pesticide residue. However, if you want your grapes to be as clean as possible, we have a few tricks up our sleeve!
Any chemical residue on the surface of grapes is likely to mingle in with the natural waxy film that forms on grape skins. Water alone will not wash this away, but luckily some common household products will.
Here’s a visual tutorial from GST Kitchen on YouTube explaining three easy ways to properly clean grapes.
Washing Grapes – The Best Way
To thoroughly clean grapes and make them safe to eat, put cold water in a bowl and add one teaspoon of baking soda and one teaspoon of salt. Stir well until these both thoroughly dissolve, then put your grapes into the water.
Give the bowl a good shake or gentle stir to ensure each grape is thoroughly coated in the water. Strain the grapes into a colander, and rinse them well with plenty of cold water.
Allow the grapes to dry naturally, or pat them dry with a clean towel.
There you have it! Clean grapes ready to eat!
So, now we’ve got all your queries about the white residue on grapes sorted, let’s take a look at some other grape-related questions!
What Is The Best Way To Keep Grapes Fresh?
A fresh grape should be plump, crisp, and juicy, with a sweet and intense flavor. But while they normally taste like this on the day you bring them home from the store, they can soon start to deteriorate.
A grape that is past its best is a huge disappointment, as that crispness turns into a mushy, over-sweet, and odd-tasting fruit.
Luckily, keeping grapes perfectly fresh involves just one simple change: take them out of the fruit bowl, and put them in your refrigerator!
The optimum storage conditions for grapes are around 30-32 degrees Fahrenheit, with humidity levels of 90% or above. This just happens to be the exact conditions that exist in your crisper drawer!
Don’t be tempted to wash your grapes as soon as you get home. This destroys the protective waxy coating that is naturally produced by the grapes.
Instead, take out only what you want to eat each day, and rinse them under cold running water before consumption.
2. Can Grapes Be Frozen?
Like all moisture-rich fruits, you can freeze grapes, but probably don’t want to. The high water content means that they will experience considerable changes in texture when they defrost.
When you freeze grapes, the water inside them expands, causing individual cells inside the grape to burst. This means that when the grapes thaw out they will be mushy and lose that crisp texture.
However, all is not lost! If you’ve got some grapes that are rapidly becoming overripe, pop them into the freezer.
You can use these to make delicious smoothies or dropped into cocktails and cold drinks on a hot day as an alternative to ice cubes.