A Detailed Guide to Making the Blueberry Buttermilk Tart
This tart combines a crisp pastry shell with a vibrant blueberry compote and a unique, tangy-sweet buttermilk ganache. The result is a dessert with a wonderful creamy texture and “about a million” vanilla dots.
Serves: 6
Part 1: The Shortcrust
A crisp, almond-infused pastry base.
Ingredients:
| Ingredient | Amount |
|---|---|
| All-purpose flour | 125 g |
| Almond flour | 25 g |
| Powdered sugar | 50 g |
| Cold butter | 75 g |
| Salt | 1 pinch |
| Egg | 1/2 |
Method:
- Combine Dry Ingredients: Place the flour, almond flour, powdered sugar, cold butter, and salt in a food processor.
- Process: Pulse quickly until the mixture resembles crumbs. Do not overmix.
- Bind: Add the half egg and mix briefly until the dough comes together.
- Roll and Chill: Roll the dough out thinly between two sheets of parchment paper. Place in the refrigerator to rest for at least 1 hour.
- Line the Tin: Use the dough to line a high tart tin (15.5 cm diameter, 3.5 cm high). Trim the edges.
- Bake: Bake the crust in a preheated oven at 175°C for about 15 minutes until golden brown.
- Cool: Let the crust cool completely in the tin.
Part 2: The Chocolate Layer
A thin layer of blond chocolate prevents the crust from becoming soggy from the compote.
Ingredient:
| Ingredient | Amount |
|---|---|
| Dulcey chocolate 32% (Valrhona) | 20 g |
Method:
- Melt: Melt the chocolate in a bowl over a bain-marie (simmering water). Remove from heat.
- Brush: Brush the cooled tart crust with a thin, even layer of the melted chocolate.
- Set: Place the crust in the refrigerator to harden while you prepare the compote.
Part 3: Blueberry Compote
A concentrated layer of fruit flavor at the bottom of the tart.
Ingredients:
| Ingredient | Amount |
|---|---|
| Caster sugar | 40 g |
| Pectin NH | 2 g |
| Blueberry purée | 80 g |
| Lemon juice | (See method)* |
*Note: The instructions mention lemon juice, though a specific weight was not listed in the ingredients. A squeeze (approx. 1 tsp) is usually sufficient.
Method:
- Mix Pectin: In a small bowl, thoroughly mix the sugar and Pectin NH together (this prevents the pectin from clumping).
- Heat Purée: In a small saucepan, heat the blueberry purée and lemon juice to 40°C.
- Combine: Stir the sugar-pectin mixture into the warm purée.
- Cook: Bring the mixture to a boil and let it simmer for a couple of minutes to activate the pectin.
- Cool & Spread: Remove from heat and let it cool slightly. Spread the compote evenly over the bottom of the chocolate-lined tart shell.
- Chill: Refrigerate the tart while you prepare the ganache.
Part 4: Buttermilk Ganache with Blueberries
A creamy, tangy, and sweet filling that melts in your mouth.
Ingredients:
| Ingredient | Amount |
|---|---|
| White chocolate (e.g., Valrhona Ivoire 35%) | 240 g |
| Blueberry purée | 40 g |
| Heavy cream | 40 g |
| Vanilla bean | 1 |
| Buttermilk | 60 g |
Method:
- Melt Chocolate: Melt the white chocolate in a bowl over a bain-marie. Remove from heat.
- Infuse Liquids: Scrape the seeds from the vanilla bean. In a small saucepan, bring the blueberry purée, heavy cream, and vanilla seeds to a boil.
- Emulsify: Pour the hot liquid over the melted chocolate. Stir in the center of the bowl with a spatula to create an emulsion. Continue stirring until the ganache comes together and looks glossy.
- Add Buttermilk: Stir in the buttermilk.
- Blend: Use a hand blender to mix the ganache until perfectly smooth.
- Fill: Pour the ganache into the tart shell (over the set compote).
- Set: Refrigerate for at least 2 hours until the ganache is fully set.
Part 5: Decoration
Ingredient:
- Edible flowers
Method:
- Just before serving, decorate the edge of the tart with fresh edible flower petals.
Tip
- Berry Selection: For the best color and flavor, use wild blueberries (often found frozen if not in season) rather than cultivated ones. They provide that deep, enchanting purple color.