Keto Apple and Blackberry Crumble
This keto apple crumble mixes sharp Bramley apple with blackberries under a buttery ground almond and flaked almond topping. Each portion has 7.3g net carbs. It serves 6 and takes 15 minutes to prepare and 35 minutes to bake.
This keto apple crumble is a proper British pudding: soft, sharp fruit under a buttery, golden crumble. It's made with real apple, mixed with blackberries to keep the carbs down, and the topping uses ground almonds instead of flour. Each portion has 7.3g net carbs. The recipe is based on some well-loved versions. Julia's keto apple crisp with blackberries on Savory Tooth, rated 5 out of 5 from 8 ratings, uses real apples with blackberries under an almond flour and pecan topping. Jo Harding's low-carb blackberry and apple crumble on KetoDiet Blog, rated 4.6 out of 5 from 266 ratings, swaps the apple for courgette and uses a simple almond and butter crumble. Raymond Blanc's apple and blackberry crumble on BBC Good Food is the classic, with Braeburn apples, blackberries, cinnamon and a flour and sugar topping.
On Reddit, an apple crumble pie shared on r/ketorecipes shows that a little real apple goes a long way: it uses just one and a half apples for 8 servings, under a crumble of almond flour, coconut flour and butter. Our twist: we use a sharp Bramley apple, which needs little sweetening and cooks down soft, add flaked almonds to the topping for crunch, and sweeten both layers with Groovy Keto Monk Fruit Decoction & Erythritol Sweetener.
What we used: Groovy Keto Monk Fruit Decoction & Erythritol Sweetener, a granulated blend of erythritol and monk fruit decoction. Our guide to almond flour and ground almonds explains which to use in a topping like this.
Groovy Keto Monk Fruit Decoction & Erythritol Sweetener
View productHow keto apple crumble compares with a classic crumble
A classic apple crumble gets its carbs from three places: sugar in the fruit, sugar in the topping and plain flour. Raymond Blanc's apple and blackberry crumble on BBC Good Food uses 120g plain flour, 60g caster sugar and 30g demerara sugar, and its nutrition panel gives 53g carbs in each of its 4 servings. This keto apple crumble swaps the flour for ground almonds and the sugar for an erythritol-based sweetener. Erythritol counts as carbohydrate on a UK label, but it's all polyols, so each portion has 14.8g carbohydrate and 7.3g net carbs. Almost all of the net carbs come from the apple and blackberries.
| Food | Carbs | Net carbs |
|---|---|---|
| Our keto apple crumble, 1 portion | 14.8g | 7.3g |
| Apple and blackberry crumble, 1 of 4 (BBC Good Food) | 53g | 53g |
| Crumble, apple, homemade, 100g | 35.0g | 35.0g |
| Eating apple, raw, 100g | 11.6g | 11.6g |
| Bramley apple, raw, peeled, 100g | 8.9g | 8.9g |
| Blackberries, raw, 100g | 5.6g | 5.6g |
The per 100g figures are UK CoFID 2021 data for "Crumble, apple, homemade" (11-1055), "Apples, eating, raw, flesh and skin" (14-319), "Apples, cooking, raw, flesh only, peeled" (14-362) and "Blackberries, raw" (14-388). The BBC Good Food figure is from its recipe's nutrition panel. Our figure is for 1 portion (1/6 of the crumble). Only ours contains polyols, so for the others net carbs are the same as carbohydrate.
Apples are one of the higher-carb fruits, so the blackberries do a lot of the work here. They have 5.6g carbs per 100g, against 8.9g for peeled Bramley. Our guide to bananas on keto has a table comparing the carbs in other fruit. The topping won't taste exactly like a flour crumble: ground almonds give a richer, nuttier, more crumbly result, a little like a frangipane crumb.
Tips for a crisp keto apple crumble
- Use Bramley apples. They're sharp, so a little sweetener goes a long way, and they cook down into a soft, fluffy layer. Per 100g, a peeled Bramley also has fewer carbs than an eating apple with its skin.
- Keep the butter cold. Cold butter rubbed in only until you have rough crumbs with a few clumps gives a crisp, crumbly topping. Warm or overworked butter turns it into a paste.
- Don't press the topping down. Scatter it loosely so steam can escape. A packed topping goes dense and soggy where it touches the fruit.
- Watch the colour. Ground almonds brown faster than flour. Check after 20 minutes and cover loosely with foil if the top is getting dark.
- For extra crunch, bake the topping first. Raymond Blanc's crumble on BBC Good Food bakes the topping on its own, then spoons it over the warm fruit. If you try it with this almond topping, keep a close eye on it, as it browns quickly.
- Let it stand. An almond topping is soft straight from the oven and crisps as it cools. Ten minutes also gives the juice time to thicken.
Keto Apple and Blackberry Crumble
- Prep time15 min
- Cook time35 min
- Total time50 min
- Serves6
- Net carbs7.3g a portion
Ingredients
For the fruit
- 250g Bramley apple, peeled, cored and cut into 2cm chunks (about 1 large apple)
- 200g blackberries, fresh or frozen
- 20g Groovy Keto Monk Fruit Decoction & Erythritol Sweetener, for the fruit
- 1 tbsp lemon juice
- 1 tsp ground cinnamon, for the fruit
For the topping
- 100g ground almonds
- 30g flaked almonds
- 25g Groovy Keto Monk Fruit Decoction & Erythritol Sweetener, for the topping
- ½ tsp ground cinnamon, for the topping
- A pinch of fine sea salt
- 60g cold unsalted butter, cubed
You will also need an ovenproof dish of about 20cm (around 1 litre) and a mixing bowl. The total time doesn't include the 10 minutes the crumble stands before serving.
Allergens: contains nuts (almonds) and milk (butter). See the allergen notes under Nutrition.
Method
- Heat the oven. Heat the oven to 190°C (170°C fan), gas 5. You need an ovenproof dish of about 20cm that holds around 1 litre.
- Make the fruit layer. Put the 250g apple chunks and 200g blackberries in the dish. Add the 20g sweetener, 1 tbsp lemon juice and 1 tsp cinnamon, toss everything together and spread it out evenly. If you're using frozen blackberries, add them straight from the freezer.
- Make the topping. In a bowl, mix the 100g ground almonds, 30g flaked almonds, 25g sweetener, ½ tsp cinnamon and the pinch of salt. Rub in the 60g cold butter with your fingertips until it looks like rough breadcrumbs with a few pea-sized clumps. Don't overwork it.
- Top the fruit. Scatter the topping evenly over the fruit without pressing it down, so it stays light. Leave a few small gaps at the edges for the juice to bubble through.
- Bake. Bake for 30 to 35 minutes, until the topping is golden and the juice is bubbling at the edges. Ground almonds brown faster than flour, so check after 20 minutes and cover the dish loosely with foil if the top is getting dark. The apple should feel soft when you push a knife through.
- Rest and serve. Leave the crumble to stand for 10 minutes before serving. The topping crisps up and the juice thickens as it cools a little. Serve it warm with a spoonful of double cream or a little pouring cream.
What to serve with keto apple crumble
- Cream: a spoonful of thick double cream, or a little pouring cream, is the simplest choice.
- Crème fraîche or Greek-style yoghurt: both add a tangy contrast to the sweet topping.
- After a roast: it's a good winter pudding after a Sunday roast, and in December it makes a lighter alternative to our keto Christmas pudding.
Adding cream or other toppings will change the nutrition figures, so the table below is for the crumble as written.
Ways to vary keto apple crumble
- Mixed spice: swap the cinnamon in the topping for ½ tsp mixed spice. Our guide explains how mixed spice differs from allspice.
- Apple and raspberry: use raspberries instead of blackberries. They have slightly fewer carbs per 100g.
- Pecan crumble: swap the flaked almonds for roughly chopped pecans, as in Savory Tooth's version.
- Individual crumbles: divide the fruit and topping between 6 small ramekins and bake for 20 to 25 minutes.
More bakes made with our sweeteners
- Keto blueberry muffins: another fruit bake with ground almonds and Monk Fruit Decoction & Erythritol Sweetener.
- Keto Christmas pudding: a festive pudding for December.
- What are polyols? Why erythritol appears under carbohydrate on UK labels.
Storage, freezing and reheating
- Fridge: let leftovers cool, then cover them and put them in the fridge within 1 to 2 hours. KetoDiet Blog says its crumble keeps in the fridge for up to 3 days. We suggest eating ours within 2 days, following the Food Standards Agency's leftover advice. The topping softens in the fridge.
- Reheating: reheat portions in the oven at 180°C (160°C fan) for 10 to 15 minutes, or in the microwave, until steaming hot all the way through. Reheat leftovers only once. The oven keeps the topping crisper.
- Freezer: KetoDiet Blog suggests freezing its crumble without the topping for up to 2 months, and we suggest the same. Freeze the uncooked fruit layer and the raw crumble mix separately. Defrost the fruit in the fridge overnight, add the topping straight from the freezer and bake as in the recipe, until the fruit is steaming hot in the middle.
The 1 to 2 hour cooling window, the 2-day fridge life and the defrosting and reheating advice follow the Food Standards Agency's guidance on how to chill, freeze and defrost food safely.
Nutrition
Per portion (1/6 of the crumble):
| Nutrient | Per portion |
|---|---|
| Energy | 244 kcal |
| Fat | 20.5g |
| of which saturates | 6.2g |
| Carbohydrate | 14.8g |
| of which sugars | 6.6g |
| of which polyols | 7.5g |
| Net carbs | 7.3g |
| Fibre | 4.9g |
| Protein | 5.2g |
| Salt | 0.09g |
Net carbs are carbohydrate minus polyols. On UK labels, fibre is already listed separately from carbohydrate, so it isn't subtracted again. Our guide to polyols explains why erythritol counts as carbohydrate. Figures are calculated from the Monk Fruit Decoction & Erythritol Sweetener pack (per 100g: 0 kcal, 100g carbohydrate, of which 0g sugars and 100g polyols) and UK (McCance and Widdowson's CoFID) data for peeled raw Bramley apple (14-362), blackberries (14-388), lemon juice (14-277), ground and flaked almonds (14-870), unsalted butter (17-661) and salt (17-367), with USDA figures for ground cinnamon. Energy is calculated from fat, protein, carbohydrate and fibre, with erythritol counted as 0 kcal, as on the pack. They will vary with the size of your apple and the brands you use. Each portion contains 7.5g polyols from erythritol. Excessive consumption may cause a laxative effect.
Allergens: the crumble contains nuts (ground and flaked almonds) and milk (butter). The Monk Fruit Decoction & Erythritol Sweetener pack says it is packed in a facility where there may be traces of nuts, cereals and milk. Always check the current labels before cooking for anyone with an allergy.
FAQ
Are apples keto?
Apples have more carbs than most fruit eaten on keto, so they're usually kept to small amounts. UK CoFID data lists 8.9g carbs per 100g for a raw, peeled Bramley cooking apple and 11.6g for a raw eating apple with its skin, against 5.6g for blackberries. That's why this crumble mixes 250g of Bramley with 200g of blackberries. Most of each portion's 7.3g net carbs comes from the fruit.
What can I use instead of flour in a crumble topping?
Ground almonds are the usual swap. Rub them into cold butter with a granulated sweetener, just as you would with flour. Flaked or chopped nuts add crunch, which is why we add flaked almonds, and Savory Tooth's keto apple crisp uses chopped pecans. Coconut flour soaks up far more butter and liquid, so don't swap it for ground almonds weight for weight.
Can you freeze apple crumble?
Yes. KetoDiet Blog suggests freezing its crumble without the topping for up to 2 months, and we suggest the same. Freeze the uncooked fruit layer in its dish or a box, and the raw crumble mix in a separate bag. Defrost the fruit in the fridge overnight, scatter the topping over it straight from the freezer and bake as in the recipe, until the fruit is steaming hot in the middle.
How do you stop a crumble topping going soggy?
Keep the butter cold, stop rubbing it in while there are still a few clumps, and scatter the topping loosely rather than pressing it down. Don't add any water, as the fruit releases plenty of juice. Raymond Blanc's crumble on BBC Good Food bakes the topping on its own first for extra crunch. An almond topping also crisps as it cools, so let the crumble stand for 10 minutes before serving.
How many carbs are in apple crumble?
A classic apple crumble has a lot of carbs. UK CoFID data lists 35.0g carbohydrate per 100g for a homemade apple crumble, and Raymond Blanc's apple and blackberry crumble on BBC Good Food has 53g carbs, 30g of them sugars, in each of its 4 servings. Each portion of our keto apple crumble has 14.8g carbohydrate, of which 7.5g is polyols from erythritol, which leaves 7.3g net carbs.
