Ultimate Guide to Soy-Based Pastry Cream

Albert
Mar 8
6 min read

Updated: Mar 13

Why Soy? Soy milk’s mild flavour blends seamlessly into recipes without overpowering other ingredients.
Key Ingredients: Soy milk, cornflour, sugar, and optional flavourings like vanilla or citrus zest.
Steps to Make It: Mix, heat, and thicken the ingredients carefully to avoid lumps or curdling.
Storage Tips: Keep it refrigerated for up to 3 days but avoid freezing - it can turn grainy.

This guide covers everything from choosing the right soy milk to fixing common issues like curdling or skin formation. Whether you're a pro baker or a home cook, soy pastry cream is a simple, reliable option for dairy-free desserts.

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How to Make Soy-Based Pastry Cream

Required Ingredients

Making soy-based pastry cream is straightforward with a handful of ingredients. These choices are key to achieving a smooth texture and balanced flavour.

Choosing the Right Soy Milk

Opt for plain, unsweetened soy milk made from just soybeans and water. Avoid versions with additives, as they can affect the natural taste and the cream's consistency.

Sweeteners and Thickeners

Use caster sugar or maple syrup for sweetness.
Cornflour or similar starch works well as a thickener.
If needed, include a small amount of agar agar or xanthan gum to stabilise the mixture.
Adjust these ingredients gradually to get the texture you prefer.

Adding Flavours

Enhance your soy pastry cream with a variety of flavourings. Consider vanilla extract, citrus zest, cinnamon, or cardamom for a twist. For a richer option, mix in dairy-free dark chocolate. Add heat-stable ingredients during cooking, and reserve delicate flavours for after the cream has cooled.

Making Soy Pastry Cream

Mixing the Ingredients

Start by combining 60g of cornflour with 100g of caster sugar in a medium bowl. In a separate bowl, whisk 500ml of room-temperature soy milk with 1 tsp of vanilla extract. Gradually add 120ml of the soy milk to the dry mixture, whisking until it forms a smooth, lump-free paste. Move on to cooking straight away to maintain the right texture.

Pour the rest of the soy milk into a heavy-bottomed saucepan. Heat it over medium heat until small bubbles appear along the edges, roughly at 70°C. Take it off the heat briefly to temper the cornflour mixture.

Cooking Methods

Add the smooth cornflour paste to the warmed soy milk. Place the pan back on medium-low heat and stir constantly with a wooden or silicone spatula. Be sure to scrape the bottom and sides of the pan to avoid sticking.

As you cook, the mixture will thicken when it reaches around 82-85°C. Keep stirring and let it cook for another 2-3 minutes once it starts bubbling, maintaining a temperature between 85-88°C. You'll know it's done when the cream coats the back of a spoon and a clean line appears when you run your finger through it.

For a silky finish, strain the cream through a fine-mesh sieve into a clean bowl. This step removes any small lumps that may have formed. Cover the surface directly with cling film to stop a skin from forming.

Storage Guidelines

Let the cream cool at room temperature for up to 30 minutes, then refrigerate it. Stored in an airtight container, soy pastry cream stays fresh for up to 3 days. If it feels a bit firm after chilling, gently whisk it to restore its smooth texture.

Take it out of the fridge 15–20 minutes before using. If you need a thinner consistency, fold in 1 tablespoon of room-temperature soy milk at a time until it reaches the desired texture.

Avoid freezing soy pastry cream, as thawing can make it grainy. It's best to prepare just enough for immediate use or within the 3-day storage period.

Problem-Solving Guide

Avoiding Texture Issues

Start by mixing cornflour and sugar well to create a smooth base. Whisk steadily in one direction to dissolve any lumps. If you notice small lumps forming, take the pan off the heat and whisk vigorously until the mixture is smooth.

Temperature control is key - stick to medium-low heat and avoid going over 88°C. Exceeding this temperature can cause the soy milk proteins to clump, creating a grainy texture. A kitchen thermometer can help you maintain accuracy.

To ensure a silky finish, strain the cream through a fine-mesh sieve to catch any remaining lumps.

Adjusting Thickness and Flavour

If the texture still isn't right, you can gradually add room-temperature soy milk in 15ml increments while whisking, until the consistency feels right. For cream that's too thin, mix 1 tablespoon of cornflour with 2 tablespoons of cold soy milk to make a slurry, then whisk it into the warm mixture over medium-low heat.

To tweak the flavour, try these simple changes:

Increase the vanilla extract to 1½ teaspoons for a deeper flavour.
Add ¼ teaspoon of salt to balance out the sweetness.
Stir in 15ml of coconut cream for a richer, creamier result.

Fixing Common Mistakes

Here’s how to deal with a few typical problems:

Curdled or Separated CreamIf the cream looks curdled, strain it through a fine-mesh sieve and blend it with an immersion blender to make it smooth again. If it separates during storage, whisk it vigorously while slowly adding 30ml of warm soy milk.

Skin FormationTo prevent a skin from forming, press cling film directly onto the surface of the cream while it's still hot. If a skin has already formed, simply remove it with a spoon and whisk the cream until smooth.

Burnt BottomIf the bottom burns, carefully pour the usable cream into a clean pan, leaving the burnt bits behind. Stir the cream frequently to avoid burning again.

Recipe Variations

Once you've mastered soy pastry cream, you can easily experiment with different flavours to suit your desserts.

Basic Flavour Options

Adding flavours is straightforward. For a classic vanilla version, mix in 2 teaspoons of vanilla extract and the seeds from one vanilla pod - perfect for French pastries.

For chocolate lovers, whisk 30g of cocoa powder with the cornflour and sugar before adding the soy milk. To balance the cocoa's natural bitterness, add 2 extra tablespoons of sugar. Once the cream cools to about 40°C, fold in 50g of melted dairy-free dark chocolate for a rich, smooth finish.

Fruit-Based Versions

Fruit flavours work beautifully with soy pastry cream. For a citrusy kick, heat the soy milk with 2 tablespoons of lemon, lime, or orange zest, then strain out the zest before combining with the other ingredients.

Prefer berries? Blend 125g of strained berry purée - like raspberries, strawberries, or blackberries - into the cooled cream. Adjust the sugar as needed, depending on the sweetness of the berries.

Using in Desserts

Soy pastry cream is incredibly versatile and works in a variety of desserts:

Fruit tarts: Spread it in a pre-baked tart shell and top with fresh, seasonal fruit.
Éclairs: Pipe it into choux pastry shells made with dairy-free butter for a creamy filling.
Layer cakes: Use it as a filling between layers of vanilla or chocolate sponge for a luscious texture.

For best results, chill the cream for at least 4 hours before piping or spreading. This helps it set properly, ensuring it holds its shape when used as a filling or topping.

Tips and Summary

Perfecting soy pastry cream is all about attention to detail. These tips will help you get consistently smooth and delicious results every time.

Start with soy milk at room temperature (around 20°C) and heat it carefully to 82–85°C. This steady temperature range is key to avoiding lumps and ensuring the cream thickens properly.

Strain the cream through a fine-mesh sieve once it's done. This step guarantees that silky, smooth texture. Allow it to cool to about 40°C before covering it with cling film pressed directly onto the surface. This prevents a skin from forming.

Choose high-quality barista or cooking soy milk. Always check the expiry date and give it a good shake before using.

Here’s what industry professionals have to say about plant-based creams:

"Our dairy-free cakes, made with almond milk, coconut cream, and vegan butter, are perfect for lactose intolerance or dairy-free lifestyles - lusciously delicious!" - Le Sud Patisserie

Le Sud Patisserie in Auckland is a great example of how versatile dairy-free techniques can be. Their plant-based desserts prove that you can achieve the same luxurious texture and flavour as with traditional pastry cream.

Store your soy pastry cream in an airtight container in the fridge for up to three days. Before using, re-whisk it, and if it feels too firm, add a little warm soy milk to adjust the consistency. For thickness, use 45–55g of cornflour per litre of soy milk, depending on your preference.