Freezing stew offers make-ahead convenience, but not all vegetables handle freezing and reheating well. Which vegetables work well for this purpose, and which ones don't?
We gathered common stew vegetables (butternut squash; carrots; celery; celery root; parsnips; peas; sweet potatoes; turnips; and red, Yukon Gold, and russet potatoes) and simmered each separately until just tender. We let them cool, froze them in covered containers for one week, and then reheated them and examined them for structural integrity. Most held their shape and texture well, but all the potatoes turned into a watery mash and the squash turned to mush with gentle pressure. Why? It all comes down to fiber. Fiber is resistant to breaking down, so the more a vegetable contains the more intact it will remain. Peas (which held together just fine) contain about 5.5 percent fiber, whereas weaker squash contains about 3.2 percent fiber, and potatoes just 1.5 percent. While squash and potatoes can handle normal cooking, freezing puts more strain on their structure as water in the vegetable expands and forms sharp ice crystals, which destroy cell walls that aren’t reinforced with sufficient fiber.
THE BOTTOM LINE: When making a stew that you plan to freeze, leave out potatoes and squash. Cook them on the side and add them to the reheated stew before serving.