The Unexpected Ingredient for Perfectly Set Fruit Jams

A not-runny berry filling—for toast, for layer cake, for crumble bars—with none of the stickiness or mutedness from cornstarch, flour, or tapioca starch?

Kiwis are key.

In 2013, Cathy Barrow—known as MrsWheelbarrow on Food52—found the secret to perfectly set strawberry jam that won't run off your biscuits or slide down a pastry crust.

"Just add a kiwi," she wrote—as if adding a kiwi were the totally naturally thing to do:

Packed with natural pectin, it will make any jam gel. Kiwi’s flavor is subtle, slightly tart and not at all intrusive. [...] Your jam will hold together beautifully, tasting of strawberries and sunshine and nothing more.

And so, a diced kiwi travels along with the strawberries as they're macerated, cooked, and canned—and everyone is better for it.

Kiwi: The Chinese Fruit Named for a New Zealand Bird

Read Article

EmilyC found out about the smart tip and repurposed it in her Mixed Berry and Walnut Crumble Bars. Since the berries don't get cooked on the stove before they're layered between the base and the sandy top, EmilyC grates the kiwi instead of chopping it:

The extra step of cooking the berries seemed way too fussy for a crumble bar, so I peeled and grated the kiwi before adding it to my berries, similar to adding grated apple to thicken fruit pie or pastry. It worked like a charm: the berry filling was juicy and perfectly set, without any of the gumminess that comes from cornstarch or flour.

Mixed Berry and Walnut Crumble Bars

View Recipe

Make these with any combination of fruit, frozen or fresh. Go one-hundred percent blueberry or use a mix of strawberries, blackberries, and gooseberries (?!). Either way, you won't be able to taste the kiwi (unless, that is, you make kiwi jam—which, because of all that natural pectin, should gel perfectly).

Your most unusual use for a kiwi? Tell us in the comments below.