Blueberry Crumble Recipe
Tossing the berries with cornstarch and lemon juice before baking thickens their juices into a jammy filling instead of a watery pool, and cutting cold butter into the oat topping (rather than melting it) keeps the crumble crisp and craggy instead of pasty.
- Prep
- 15 min
- Cook
- 45 min
- Total
- 1 hr
- Servings
- 8
Ingredients
- 5 cups fresh blueberries
- 1/3 cup granulated sugar
- 1 tablespoon lemon juice
- 1 teaspoon lemon zest
- 2 tablespoons cornstarch
- 3/4 cup all-purpose flour
- 3/4 cup old-fashioned rolled oats
- 1/2 cup brown sugar, packed
- 1/2 teaspoon ground cinnamon
- 1/4 teaspoon salt
- 1/2 cup unsalted butter, cold and cubed
Nutrition per serving
- Calories
- 241
- Protein
- 4g
- Carbs
- 45g
- Fat
- 6g
Based on the recipe as written, one serving. Recalculates if you swap an ingredient above. An estimate only, exact values depend on the specific ingredients used.
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Instructions
- 1Preheat the oven to 375°F (190°C) and set an 8x8-inch baking dish nearby.
- 2In a large bowl, toss the blueberries with granulated sugar, lemon juice, lemon zest, and cornstarch until the berries are evenly coated. Spread the mixture into the baking dish.
- 3In a separate bowl, whisk together the flour, oats, brown sugar, cinnamon, and salt.
- 4Add the cold, cubed butter and work it into the dry mixture with your fingers or a pastry cutter until the topping forms clumps ranging from pea-sized to marble-sized, don't overwork it into a smooth paste.
- 5Scatter the crumble topping evenly over the blueberry filling, leaving some gaps so steam can escape.
- 6Bake for 40-45 minutes, until the topping is deep golden brown and the filling is bubbling thickly around the edges.
- 7Let the crumble cool on a rack for at least 15-20 minutes before serving; this gives the juices time to set.
Tips & variations
- Frozen blueberries work well and don't need thawing first, but they release more liquid, so add an extra teaspoon of cornstarch and expect 5-10 extra minutes in the oven.
- Swap up to half the blueberries for chopped rhubarb or blackberries for a mixed-berry version.
- A pinch of ground nutmeg or cardamom in the topping adds depth without overpowering the berries.
- For extra crunch, stir 2 tablespoons of chopped pecans or almonds into the crumble topping before baking.
Storage & reheating
Cover and store leftover crumble at room temperature for up to 2 days, or refrigerate for up to 5 days. Reheat individual portions in a 350°F (175°C) oven for 10-15 minutes to re-crisp the topping; microwaving works but leaves it soft. To freeze, bake fully, cool completely, and freeze covered for up to 3 months; thaw overnight in the fridge before reheating.
Tips from the Tulo kitchen
- Rinsing and thoroughly drying the blueberries before tossing them with sugar keeps the filling from starting out too wet.
- If the topping is browning faster than the filling is bubbling, tent the dish loosely with foil for the last 10 minutes.
FAQ
Can I use frozen blueberries instead of fresh?
Yes, straight from the freezer with no need to thaw. Add an extra teaspoon of cornstarch to account for the extra liquid they release, and expect the bake time to run 5-10 minutes longer.
Why is my blueberry crumble filling runny?
This usually means it was cut into before it finished cooling. The cornstarch thickens fully as the filling cools, so give it at least 15-20 minutes off the heat before serving.
What's the difference between a crumble and a crisp?
A crumble topping is just flour, sugar, butter, and spices, while a crisp topping includes oats for extra crunch and texture; this recipe uses oats, which technically makes it a hybrid, but the terms are used interchangeably in most kitchens.
Can I make blueberry crumble ahead of time?
Yes. Assemble the unbaked filling and topping separately, cover, and refrigerate for up to 24 hours, then combine and bake when ready, or bake it fully in advance and reheat before serving.
