Why Is My Crumble Topping Not Crunchy? (Crisp It Up)

The magic of a crumble pie lies in the contrast between the tender, juicy fruit and the crunchy, buttery topping. So, it’s really disappointing when your beautiful dessert turns out dry and powdery or, worse still, soggy. Why is your crumble topping not crunchy?

A crumble topping turns out powdery if you don’t add enough butter or process the crumble too finely. A soggy topping means too much butter, too thick a topping, or a soupy filling. For a crisp topping, balance the flour and butter, create a coarse crumb, and chill the crumble before baking.

A crumble (also known as a crisp) is a simple combination of soft, sweet fruit covered with a streusel topping of butter, flour, and sugar. The secret to a crunchy crumble lies in how you combine these ingredients and in what proportions. Let’s investigate why a crumble topping doesn’t turn crunchy and how you can crisp it up.

Why Is Your Crumble So Powdery?

The first reason a crumble topping isn’t crunchy is that it’s too dry, with more flour than butter. You’ll notice immediately that the topping is powdery and floury, with none of the caramelized nuggets of pastry you want.

A crumble topping turns out powdery when:

• You don’t add enough butter. If you can see the mixture is too dry, add a little more cold butter and rub it in, or a little melted butter and mix.
• You have processed it too finely. The crumble needs to be crumbly, with a coarse, crumb-like texture, not a soft, sandy consistency. Avoid rubbing in the butter as if you were making scones – lumps of butter are essential.
• You have pressed it down too hard. Scatter the topping over the fruit rather than patting it firmly. You will end up with a dense, cake-like topping that can be soggy below and dry on top, the worst crumble failure.

Why Does My Crumble Topping Go Soggy?

The opposite of a powdery topping is a soggy, greasy crumble, where there is too much butter and not enough flour.

A crumble topping goes soggy when:

• You add too much butter. Add a little more flour, which will soak up the extra butter. This can happen if you use melted butter rather than rubbing in cold butter.
• Your crumb topping is too thick – it should be less than an inch deep. A hefty layer of crumble topping will become dense and fatty, unable to crisp up in the oven.
• You didn’t add cornstarch or sugar to wet fruit. A crumb pie uses raw fruit, which cooks in the oven, releasing its luscious juices. If there’s no thickener in the filling, the fruit will get soupy, making the topping soggy.

Crumble is usually made with dedicated cooking apples which don’t break down and go soggy from baking. See my post on how to make crumble with an eating apple.

How To Make Your Crumble Topping Crisp

Because a crumble contains so few ingredients in a crumble, there are only a few places you can go wrong. Avoid the pitfalls of powdery or soggy crumble topping by following these tips for a crisp crumble.

Get The Butter Right

Butter is the ingredient that makes your crumble turn brown and crispy. For an excellent crumble, you must get the type and proportion of butter right.

The top tip for a toothsome crumble is to use real dairy butter. Nothing else will give you the same rich flavor and crisp texture. Vegans can use coconut oil or non-dairy butter, but it won’t be as crunchy and decadent.

Another butter tip is to use enough butter – many pastry chefs use the 3:2:1 ratio for the crumble topping, using three parts flour, two parts butter, and one part sugar. Always add more butter if the crumble looks too dry. Before popping it in the oven, you can also dot the crumble with butter.

Use the coldest butter you can, grated into the dry ingredients. Melted butter can turn your crumble soggy.

Use Brown Sugar

The best crumble toppings use brown sugar (alone or mixed with white sugar) to enhance that gorgeous caramelization. The various kinds of brown sugar will give your crumble different qualities:

• Golden-brown demerara sugar makes the topping chewy and crisp. Dust the crumble lightly with demerara sugar before baking to add a caramel kick.
• Soft, brown muscovado sugar creates a fudgy flavor and texture.
• Golden caster sugar or granulated sugar gives the crumble a shortbread-like consistency.

Make A Rough Crumble

The ideal texture of a crumble topping is clumpy, like very coarse breadcrumbs or small pebbles.

To achieve this texture, it’s best to rub the butter in by hand, as a food processor or blender can quickly blitz the ingredients into a sandy powder, making a dry crumble.

Take care to work the topping into little crumbly balls, which you can scatter over the waiting fruit – think tiny, buttery cookie balls rather than a pastry layer. Leaving space rather than packing on the topping allows the heat to circulate and crisp up the little crumble pieces.

Add Crunchy Bits 

Add extra elements to the essential ingredients if you enjoy a chewy topping. 

However, adding oats or nuts technically means you’ve turned your crumble into a crisp, but don’t let definitions stop you. 

Consider adding:

• rolled oats
• ground almonds or almond flour
• chopped nuts, such as walnuts, almonds, or hazelnuts
• seeds 
• coconut flakes.

Chill It Down

An old trick is to mix up the topping, lay it on a baking sheet, and chill the crumble in the freezer for 10 minutes. 

The idea is to slow the melting of the butter in the oven so that it keeps its shape while baking – the same theory as making shortcrust pastry or shortbread. You will end up with a lumpier, crunchier crumble.

Make a double batch of crumble topping. Store extra in the freezer so that you can instantly put together a crumble pie when you suddenly need a dessert for a potluck.

Avoid A Soupy Filling 

One of the culprits that prevent a crunchy topping is the fruit itself.

Using apples or pears is a safe bet, but stone fruit or berries release a lot of juice when heated. There are two ways to avoid this:

• Add a thickener, like cornstarch, to the filling to soak up the liquid.
• Sprinkle the fruit with sugar and a pinch of salt. Let it macerate for a while. The sugar will make the fruit release its juices, and you can then drain off all but two tablespoons.

How Do I Know When My Crumble Is Done?

You’ll know your crumble is done when:

• The topping is golden brown, indicating caramelization. Don’t start too hot and burn the topping – ensure the filling is cooked then put it under the broiler if need be.
• The filling is bubbling. Bubbling shows that the filling has boiled, and any cornstarch in the filling has thickened.

A crumble is not an instant dessert and needs a surprisingly long, slow baking time to ensure that the fruit is succulent and the topping is crunchy.

Most recipes recommend that you bake your crumble at a moderate temperature of 350-375⁰f (180-190⁰C) for around 40 minutes, depending on how deep your pan is. 

Too hot an oven will burn and blacken the topping before the fruit has had a chance to cook through and break down.

Conclusion

Hopefully, you now know why your crumble topping isn’t crunchy. For a perfectly crisp crumble topping with the crunch you love, use the correct proportions of dairy butter, flour, and brown sugar to avoid powderiness or sogginess.