What you see: A squash that’s stringy on the inside.
What it is: An old squash. Aging made the squash’s internal plumbing visible.
Eat or toss: It probably won’t taste as good, but it’s not unsafe. Consider using it in a dish where the squash doesn’t play a staring role.
Can you eat squash with stringy flesh?
One great feature of squash is it keeps well. But nothing stays good forever and here we have a squash that spent too much time on the shelf.
As this honeynut squash sat in my pantry, it was still alive and preparing for the next chapter in its squashy life. Top priority: fueling up its seeds via a tangle of internal transport channels (which you may remember from grade school as “phloem” and “xylem” tissues).
In a perfectly ripe squash you see some of those fibers in the seed cavity, but they’re also seamlessly worked into the smooth flesh of the rest of the squash. That changes, however, when the squash finishes topping off its seeds and gets ready to self destruct.
“And so the seeds are saying, ‘OK, I’m ready, I’m mature,’” explained Penelope Perkins-Veazie, a horticulture science professor at North Carolina State University. “So the flesh is basically just saying, ‘OK, it’s time to break down.’ Eventually what’s going to happen is that fruit will fall apart and it will allow the seeds to be dispersed.”
The squash’s starches had been keeping the flesh firm by holding the cells together, Perkins-Veazie explained. But as the natural breakdown process turns sturdy starches to small, water-soluble sugars, the flesh falls away, revealing those transport fibers.
Hence, stinginess. (And, of course, this stringiness is different from what we see in spaghetti squash, where the flesh easily forms pasta-like strings when coaxed with a fork; that has more to do with the spaghetti’s squash’s unique texture than aging.)
Texture and flavor decline with age
While things are getting stringy, the taste is also deteriorating. For example, a winter squash, like a honeynut or butternut, converts beta carotene, that nutrient we love for its health benefits and vivid orange color, to something similar, but differently flavored, called beta ionone, Perkins-Veazie said.
Beta ionone is also present in a perfectly ripe squash and contributes to the fruit’s distinctive taste, but too much of it can cause icky flavors (which we detect through the squash’s “volatiles” or “aroma molecules”).
All in all, a stringy squash like this won’t give you the best culinary experience.
“So the starch is gone,” said Perkins-Veazie, who studies how produce behaves after harvest. “It’s just really thin and kind of runny when you cook it. Then it has a kind of stringy feel to it and then it then it has off flavors because the beta carotene has gone to the next level of volatiles and they have a weird flavor. Put all that together and it’s like ‘yech.’”
Yech indeed! So, confession time: I ate this squash. I didn’t find it as horrible as Perkins-Veazie might have, but it did roast up to a thinner, almost gloopy consistency and the flavor was more intensely squashy (all those beta ionones!) than I would have liked.
So, how long can you store a butternut squash?
With all this talk about what happens to squash as it ages, you may be uncertain about storing it. First things first: don’t refrigerate winter squash like honeynuts or butternuts. The 40 degrees Fahrenheit or less required for safe refrigeration is too cold for whole squash. (Chopped winter squash should be refrigerated and used within several days; summer squash, like zucchini, should be stored in the fridge.) Refrigeration weakens winter squash’s cells and causes enzymes to misfire; it can actually accelerate decay.
So, the fridge is too cold, but here’s the rub: room temperature is too warm. One consequence of high temperatures is flesh breakdown, reports the University of California’s Postharvest Center. Perhaps the squash featured at the top of this post would have fared better if it had been stored in a cooler place. But how cool?
According to SaveTheFood.com, butternut squash and pumpkin are best stored for two to three months at 55 degrees. The University of California has found that, depending on the variety, winter squash can last for two to six months at 55 to 59 degrees. That’s definitely colder than room temperature.
So, unless you have a root cellar (or a squash fridge), you can’t win. The best compromise is to err on the warmer side and keep squash in a pantry. Ideally one that is dark, cool and well ventilated. But since it will most likely be above 55 degrees, the actual shelf life will be hard to predict.
In my kitchen, I find wide variation in how long fruits and vegetables last, even when I store them consistently. This probably has to do with factors that are hard for a consumer to know or control, like field conditions during growth, when and how an item was harvested and how it was stored before it was purchased.
So, while squash generally stores well, to avoid stringiness and other surprises, I try to use it within a month.
- Penelope Perkins-Veazie. Professor of Horticultural Science. North Carolina State University.
- Pumpkin and Winter Squash. Vegetable Produce Facts. Marita Cantwell and Trevor V. Suslow, Department of Plant Sciences, University of California, Davis. Postharvest Technology Center. University of California.
- The Biochemistry and Antioxidant Properties of Carotenoids. Oguz Merhan. Chapter from “Carotenoids” by Dragan J. Cvetkovic and Goran S. Nikolic.
- Pectin. Britannica.
- Squash, winter. SaveTheFood.com. STORE IT: Our Interactive Storage Guide – With Tips, Tricks and Info to Keep Your Food Fresh and Tasty For As Long As Possible.