Keto Custard Tarts With Almond Flour Pastry

The ketogenic diet adapts surprisingly well to British classics when you know the right ingredient swaps. These custard tarts replace wheat flour with finely ground almonds and use erythritol instead of sugar, delivering the same creamy texture with 85% fewer carbohydrates than the traditional version.

Why almond flour works for keto pastry

Almond flour contains just 6g of net carbs per 100g compared to 70g in plain wheat flour. Its higher fat content (50g per 100g) creates a crumbly texture that holds shape when baked. Research suggests nuts like almonds may support better blood glucose control compared to refined grains, making them a logical choice for low carb baking. A 2008 study in Lipids found that replacing carbohydrates with nuts improved multiple metabolic markers in participants with insulin resistance.

The custard dilemma solved

Traditional custard relies on sugar and cornflour – two ingredients incompatible with ketosis. This version uses:

Double cream (3g carbs per 100ml at Tesco for £1.20)
Egg yolks for natural thickening
Granulated erythritol (£4.50 for 500g at Sainsbury’s)
Vanilla extract and nutmeg for authentic flavour

The result sets firmly without grain-based thickeners, with 3.5g net carbs per tart versus 25g in a standard supermarket version.

What this means in practice

You’ll need a 12-hole muffin tin and baking beans for blind baking the pastry cases. In cooler British kitchens (below 18°C), the almond flour dough handles better when chilled for 30 minutes before rolling. For the custard, warming the cream gently prevents curdling – aim for steam but no bubbles. A sprinkle of cinnamon or grated dark chocolate (85% cocoa or higher) makes an elegant finish when serving.

Storage and adaptations

These keep for three days refrigerated or freeze well for up to a month. For dairy-free versions, coconut cream can replace double cream, though it will impart a subtle tropical note. Those managing common keto electrolyte imbalances may appreciate the 180mg potassium per tart from the egg yolks.

Frequently asked questions

Can I use coconut flour instead?

Coconut flour absorbs more liquid and requires additional eggs to bind. We recommend sticking with almond flour for this recipe’s ratios.

Why did my custard split?

Overheating causes egg proteins to coagulate too quickly. Use low heat and stir constantly until the mixture coats the back of a spoon.

Are these suitable for people with diabetes?

While lower in carbs, individuals managing blood glucose should account for the erythritol and cream in their meal plan. Consult your healthcare provider.

The bottom line

These keto custard tarts prove you don’t need sugar or wheat to recreate British teatime classics. The almond flour pastry provides structure without spiking blood sugar, while the rich custard filling satisfies sweet cravings. If you’d rather not do the macro maths yourself, the Keto Dieting app does it for you on Google Play and the App Store.

Educational only — not medical advice. This article is for general information. Speak to your GP before changing your diet, especially if you have type 1 or type 2 diabetes, kidney or liver disease, are pregnant or breastfeeding, or take medication for blood pressure, cholesterol, or blood glucose.

References

Volek JS, Phinney SD, Forsythe CE, et al. (2008). Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids. https://doi.org/10.1007/s11745-008-3274-2
Paoli A, Rubini A, Volek JS, Grimaldi KA (2013). Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition. https://doi.org/10.1038/ejcn.2013.116