What you see: White areas on your raspberry.
What it is: Sunburn or sunscald.
Eat or toss: Eat! The raspberry is fine.
Raspberries with white areas are OK to eat
First, some fun facts: Each tiny bead of fruit that makes up a raspberry is known as a “drupelet.” And each raspberry includes more than 50 drupelets. Neato!
Obviously we expect our raspberries to be thoroughly red in color. But some areas on the drupelets pictured above appear to have given up the ghost.
The white color is evidence of sunburn or sunscald, and it can show up on both raspberries and their blackberry cousins. The white drupelets look weird, but the berries will still taste fine, possibly a little less flavorful. For aesthetic reasons, inspectors won’t allow berries like these into your supermarket pints, but if you see them at a farmers market or U-pick operation, don’t be afraid to eat them – consider it a sweet way to fight food waste.
And, just to be clear–in this post we’re talking about raspberries where the fruit itself is white. If you see a white growth or fuzz on your berries, you’re probably looking at mold and shouldn’t eat them (though neighboring, unafflicted berries are probably fine.)
High temperatures can cause white areas on raspberries
As plants, raspberry bushes obviously need sunlight for energy. Sunlight on its own won’t “burn” a berry. Instead, a combination of ultraviolet rays, heat and dry air seems to be the recipe for white drupelets, especially if those conditions come after a sudden weather shift. This article from the University of California notes that humid conditions help prevent raspberry sunburn because the water molecules in the air deflect and absorb solar radiation. When temperatures rise and there’s less moisture in the air, the fruit gets hotter and berry burn is more likely.
“Maybe the weather changed and suddenly we’ve got real hot days without much humidity and so they’re getting a lot more UV radiation than they than they were used to,” said Mark Longstroth, a retired fruit educator at Michigan State University.
Longstroth pointed out that sunburn doesn’t take over an entire bush or even an entire fruit.
“You don’t see it on all the fruit, you just see it on the ones that, through some accident of the architecture of the bush, are exposed to more light at certain times of the day,” he said.
Longstroth noted that some other types of fruits are vulnerable to sunburn as well (we previously wrote about a sunburnt tomato). In hot apple-growing regions, he said, growers sprinkle orchards with water to cool them.
SOURCES:
- Mark Longstroth. Retired Small Fruit Educator. Michigan State University Extension.
- Non-pest problems in raspberries. University of Minnesota Extension. Annie Klodd, Extension educator, fruit and vegetable production. Reviewed in 2022.
- Sunscald on Raspberry. Mark Bolda. Oct. 14, 2011. Agriculture and Natural Resources. University of California.
- Parts of the berries on my red raspberries are white in color. Why? Iowa State University Extension and Outreach.
- Sunburn on raspberries, apples and grapes. Annie Klodd, Extension educator, fruit and vegetable production. University of Minnesota Extension. July 23, 2020