Sohla's magic ratio for turning any fruit into a crumble

How to take fruit crumbles off-script with confidence

By Sohla El-Waylly
Published July 4, 2021 1:30PM (EDT)
Prop stylist: Andrea Foti. Food stylist: Anna Billingskog. (James Ransom / Food52)
Prop stylist: Andrea Foti. Food stylist: Anna Billingskog. (James Ransom / Food52)

This story first appeared on Food52, an online community that gives you everything you need for a happier kitchen and home – that means tested recipes, a shop full of beautiful products, a cooking hotline, and everything in between!

Every month, in Off-Script With Sohla, pro chef and flavor whisperer Sohla El-Waylly will introduce you to a must-know cooking technique — and then teach you how to detour toward new adventures.

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When playing around with dessert, you usually have to tread carefully. Swap brown sugar for white sugar in a delicate chiffon cake, and you'll change the moisture, the pH, the way the leavening reacts in the batter . . . in other words, it'll be a hot mess. But fruit crumbles are endlessly forgivable, no structural integrity necessary. You can run wild and free and create whatever crumble is calling your name. Today I'll show you how.

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The Filling

Fruit

Fun thing about fruit — it's mostly water. Because plump blueberries, fuzzy peaches, and suggestive cherries are all just tasty little water balloons, they mostly act in the same way. Which means all you need is a scale (you'll love it! I promise!) and my golden ratio:

1,000 grams fruit 
100 grams sweetener 
20 grams starch 

Because most fruits have roughly the same water content, they need roughly the same amounts of sugar and starch to cook up into a saucy filling. I like 10% sugar and 2% starch, based on any given weight of fruit. Those amounts can be tweaked, depending on how sweet or juicy your fruit is and how thickly set you like your filling, but that's a solid place to start.

Sure, I could offer up volume measurements for the fruit — but that would take away your ability to riff; 1 cup of blueberries will not be the same weight as 1 cup of sliced peaches or 1 cup of pitted cherries, so the only way to spread your wings is to use a scale.

Frozen fruit works just as well as fresh. Why, you wonder? Frozen fruit is processed at the peak of freshness, and is often more flavorful than out-of-season fresh fruit. You can bake with still-frozen fruit, but I prefer to thaw it first, so the edges of my crumble don't overbake while the center is catching up. And be sure to use all the juices that weep out of the thawed fruit (frozen fruit isn't juicier than fresh, but the process of freezing and thawing breaks down the fruit, so it may appear as such).

Sweetener

Sugar doesn't just sweeten a dessert; it adds to the texture and stability, too. For my Go-To Vanilla Pound Cake, if you try something seemingly innocent, like reducing the sugar by 1/2 cup, your resulting cake won't be as fluffy, and it'll quickly grow tough with the additional folds needed for mix-ins. If a chocolate chip cookie calls for dark brown sugar and you swap in light, the acidity of the cookie dough will decrease, changing the way the baking soda reacts and affecting its lifting powers.

Luckily, I don't care how stable my fruit crumble is (not something I can say about any other aspect of my life). If it grows thick after sweetening with honey, I can get down with that. If ultra-ripe strawberries create an extra juicy filling, I'll just funnel it into my mouth. Unlike a fruit pie, which needs a higher ratio of starch and sugar, not only to be sliceable but also to avoid a soggy bottom, crumbles are blissfully spoonable.

This is one recipe where the sweetener is primarily for sweetening. OK, and for body, too — so don't get too crazy and omit or swap the sweetener completely for a sugar-free alternative, like xylitol or stevia. My recipe uses the minimum amount of sugar needed. Beyond that, go wild.

Maple syrup and brown sugar for a spiced pear crumble? That can get it! Coconut sugar with pineapple and a splash of rum for a crumble with toasty tropical vibes? Please do! Treat the measurement for the sweetener as a starting point, add more to taste, and try out various combos to your heart's content.

Starch

Starch helps thicken the juices released by the fruit into a glossy, jammy sauce. Without it, your fruit will be swimming in runny, hot juice, and that's no fun.

Truly any starch will do, from regular all-purpose flour to sticky sweet-potato starch — but think about how each starch behaves and whether that's gonna get along with your crumble hopes and dreams. Flour can get, well, floury. That's why most recipes with cooked fruit fillings, such as those in a crumble, cobbler, or pie, call for either cornstarch, arrowroot, or tapioca starch. They all cook up relatively flavorless, allowing the fruit to shine.

I prefer tapioca starch, which thickens at a lower temperature than cornstarch. This means I only have to cook my crumble until I see it bubbling around the edges to know that the starch is fully hydrated and activated. On the other hand, a cornstarch-thickened crumble needs to be baked until you see bubbles in the center of the dish, which requires you to bake it longer, losing some of that fresh fruit goodness. Another added bonus of tapioca starch is that it sets into a clear, smooth gel, while cornstarch can become murky and gloopy.

Ultimately, use what you've got, but know that there are different gelatinization temperatures for various starches, and they each thicken the fruit juices in their own way.

Bonuses

Lemon juice and a big pinch of kosher salt will never disappoint, but think outside the box and get creative with flavors. In-season fruit is especially floral, so try accenting that with a little dose of rose water, orange blossom water, or almond extract. Add brightness with something unconventional, like ground coriander or sumac. Whatever your choice, use a light hand, so you never overwhelm the flavors of the fruit.

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The Topping

This is what we're here for! Without a buttery, crumbly, crunchy topping, would this even qualify as dessert? As I've confessed with my Black & White Pound Cake, I like a generous quantity of big boulders whenever streusel is involved.

Now, remember when I said the key to riffing with the fruit filling is measuring by weight? Plot twist: For the crumble, volume is preferable. Here's why:

There's a misconception that, when it comes to baking, weight is king. Using a scale does ensure precision and consistency — however, to fully understand a recipe and take it off-script, it helps to look at both weight and volume. For this crumble, what matters is the amount of space each ingredient takes up in the mixture. Here's my streusel strategy:

1 1/2 cups flour 
2/3 cup granulated sweetener 
2/3 cup textural mix-in 
10 tablespoons fat 

Swap up to 1/2 cup of flour for another flavorful powder, such as cocoa, matcha, powdered freeze-dried fruit, kinako flour, cornmeal, even blitzed-up Cheez-Its. (Any more and your mix won't have enough structure.)

Use any granulated sweetener, like sugar of any shade, coconut sugar, or grated piloncillo. Avoid liquid sweeteners, which can make the crumble chewy. Just keep in mind that the darker the sugar, the faster the crumble will brown, so use a foil shield if the crumble begins to get too dark.

For the textural mix-in, think granola vibes: nuts, seeds, oats, cornflakes, or wheat bran. No need to toast them in advance; they will have plenty of time to get roasty in the oven.

Butter is my choice of fat for crumbles. It's super flavorful and solid at room temperature, so you'll end up with a streusel that readily clumps together and doesn't get greasy after baking. However, you can swap out up to half the butter for another fat, to bring in some extra flavor and dimension. Try extra-virgin olive oil, virgin coconut oil, or even duck fat.

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What Are You Waiting For?

Now that you know the basics, go forth! Take fruit crumbles off-script with confidence. Get started with one of my two recipes below to hone your skills. Then let me know in the comments what combinations you're dreaming up.


Sohla El-Waylly

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