Everybody’s Using This Trick to Find the Sweetest Blueberries, But Does it Actually Work?

Every year, I try to figure out what fruit is in season so that I get the freshest produce and save some cash (because it’s cheaper in season). Because it’s summer and blueberries are in season, they're one fruit at the top of my shopping list, but I've noticed that the flavor isn't consistent. You could have a pint of the sweetest blueberries or a bunch of sour ones that make you cringe.

Leave it to social media to come up with an answer for our most pressing produce problems, like testing the sweetness of blueberries. This blueberry float test is all over our FYP, including a video is from Dzung Lewis’s Honeysuckle page, whose Instagram video tests the theory of another social media creator’s solution.

The idea here is to add your blueberries to a bowl of water and observe which ones floated and which ones sank. The theory is the sweet ones will sink and the sour ones will float to the top. Lewis’s results were inconclusive, and she had lots of questions about whether the fruit’s color, size and weight had any impact on their buoyancy or taste.

Lewis certainly isn’t the only person to have these questions. In fact, I have the same thoughts when I buy blackberries and raspberries. So, does this method have any merit or is it bust? We asked a horticulture expert to get the straight scoop.

Related: What Happens to Your Body if You Eat Blueberries Every Day, According to a Registered Dietitian

How Does the Blueberry Float Test Work?

Before we get to the expert’s opinion on how to determine the sweetness of a blueberry, let me explain what Instagrammer Honeysuckle did doing her testing. She admits that she has been a “bit skeptical” of this hack, but for the sake of blueberry lovers, she wanted to try it.

She started by pouring a pint of blueberries in a glass bowl of water. She had 6 floaters, and they were a combination of tart, sweet and sour. In her experiment, the ones that sank were “very sour.” Overall, Lewis rated the blueberry hack a 6 out of 10.

Does the Blueberry Float Test Really Work?

We spoke with horticulturist Chris Enroth from the University of Illinois Extension to see if this hack was legit. According to him, the water trick is an acceptable method to gauge the sweetness of blueberries. “The blueberry float test does have merit to identify ripe blueberries with a higher sugar content. It has been used for many years in commercial blueberry packing.” says Enroth.

How Does the Float Test Determine the Sweetness of Blueberries?

When you pour the blueberries in a bowl of water, they have a mind of their own— some rise to the top, while others sink. Enroth explains why.

“During the float test, ripe blueberries sink because they have developed sugars within the fruit that give them a higher specific gravity. In other words, sweet blueberries are denser than water, allowing them to sink. Unripe or more sour-tasting blueberries have a lower sugar content, therefore making them less dense and able to float on the water's surface.”

He further explained, “One misconception that comes to mind is that not all blueberries have a high sugar content. Many factors influence how much sugar develops in a blueberry, including soil nutrients, soil pH, and weather. Probably the most critical is the cultivar of blueberries being grown. Some cultivars are naturally sweeter than others. In a study of five blueberry cultivars, 'Bluejay' and 'Nelson' were found to have significantly higher sugar content.” Unless you're picking your own (more on that in a minute), you're not going to know which type of blueberries are in your container.

Related: 'I'm a Neurologist—This Is the Fruit I Eat Almost Every Day for Brain Health'

Are There Ways to Tell if a Blueberry is Ripe?

According to the USDA, a good way to tell if a blueberry is ripe is by the color. In general, green berries are under-ripe before turning pink, then ripening to a deep blue. When the berry’s flesh is mushy and soft, it’s overripe.

If you have the option, Enroth recommends that you pick your own blueberries for the sweetest fruit. Here's his advice for picking the best blueberries in the field and also what to look for in the package.

“My preferred way to tell if a blueberry is ripe is by touch and to pick them fresh myself. A few tips for picking blueberries: Pick berries in the morning after the dew has evaporated or later in the day when the fruit is naturally cool. Select fully ripe berries that are firm, dry, plump and have smooth skin. Berries should be deep purple, blue to blue-black and have a powdery, silver-white bloom on the skins. They should easily be removed from the stem (practically falling off in your hand). Berries turn blue 3 to 4 days before they attain maximum sweetness and flavor. Avoid picking green or reddish berries; they're not ripe. Size is not an indicator of maturity.”

Do Blueberries Ripen After They're Picked?

Blueberries, like many other fruits , need to be picked at the right time to ensure the best taste. As Enroth explains, “The time of picking is important. Berries that have already turned blue or dark purple will continue to develop sugars after being picked. Green or red fruit will not ripen fully after being picked.”

So, there you have it. Social media has enlightened us again. Of course, this method isn’t foolproof (I tried it myself and some sinkers were a bit sour), but I do believe that it’s a valid way to get a general sense of which blueberries are the sweetest.

The Best Ways to Use Blueberries

Regardless if they’re sweet or sour, blueberries can be used in all sorts of ways. Here are some of our favorites.

• Bake with them. Try making a blueberry cobbler , a slab pie , scones or a batch of muffins .
• Blend them. For a great breakfast or snack, make a blueberry smoothie . One great option: Chris Hemsworth’s almond and blueberry smoothie .
• Eat them fresh. Who says you have to do anything to them? Toss fresh blueberries with other berries for the ultimate sweet, juicy antioxidant-packed snack.

Sources:

• Chris Enroth, Horticulture Educator, University of Illinois Extension
• USDA.gov, Natural Resources Conservation Service, National Blueberry Month
• USDA.gov, United States Standards for Grades of Blueberries
• USDA.gov, Picking a Winner Part II - More Tips and Insights for Selecting Seasonal Produce

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