Hazelnut Praline — caramelised hazelnuts ground to a flowing paste

i. Origin & history

The word praline is French, and its origin story goes back to the seventeenth century. The tale usually told is that the cook of César, duc de Choiseul, comte du Plessis-Praslin — a marshal of France and diplomat under Louis XIII and Louis XIV — coated almonds in boiling sugar, and the result was named after his master. Whether or not the story is accurate, the first pralines were whole almonds in a crunchy sugar shell, a sweet still made in France today, including the pink pralines of Lyon used in the praline tart.

Over time the word spread and changed meaning in different places. In New Orleans, French settlers' pralines became soft, fudge-like discs of pecans, brown sugar and cream. In Belgium, a "praline" means a filled chocolate, a usage associated with the Brussels chocolatier Jean Neuhaus in the early twentieth century. And in French pastry kitchens, praliné came to mean the smooth paste of caramelised nuts ground fine, while pralin refers to the same caramelised nuts crushed into crunchy pieces rather than ground to a paste.

Praliné became indispensable in French pâtisserie in the nineteenth and twentieth centuries. It flavours the Paris-Brest, praline buttercream for dacquoise and other cakes, praline mousse, ice cream, chocolates and the crunchy praliné feuilletine layers of modern entremets. Hazelnuts are the most common choice, often blended with almonds; the best paste is made from intensely flavoured varieties such as Piedmont's Tonda Gentile.

Commercial praline paste is widely available to professionals, but homemade praline has a deeper, fresher flavour, and it is surprisingly simple to make with a good food processor.

ii. How solid caramel turns into a liquid paste

The transformation from brittle to flowing paste can look like magic, but it is simple physics. Hazelnuts are around 60% fat. When caramelised nuts are ground, the blades first break the brittle into powder, then crush the nut cells, releasing their oil. As grinding continues, the friction warms the mixture, the oil coats the fine sugar and nut particles, and the powder clumps into a ball, then loosens into a thick paste and finally into a smooth, pourable liquid. Patience is essential: it can take 10 minutes or more in a domestic processor.

Pastry chefs use two methods to caramelise the nuts. In the dry caramel method, sugar is melted alone to an amber caramel and poured over the toasted nuts. In the sablé (sandy) method used here, a syrup of sugar and water is boiled to about 118 °C, the nuts are added, and stirring makes the sugar crystallise into a sandy white coating; continued heating then melts that coating into caramel around each nut. The sablé method caramelises the nuts more evenly and gives more control.

The ratio of nuts to sugar defines the praliné. A classic praliné is roughly 50% nuts, 50% sugar; "praliné 60%" contains more nuts and is less sweet and more intense. This recipe sits at about 60% nuts for a fuller flavour.

The colour of the caramel matters: it should be a deep amber, like dark honey. Too pale, and the praline tastes simply sweet; too dark, and it turns bitter. A pinch of salt sharpens the flavour noticeably.

iii. Ingredients

Makes 10 servings · scroll the side panel to adjust

• 300 g blanched hazelnuts
• 200 g caster sugar
• 60 ml water
• ½ tsp fine sea salt
• ½ vanilla pod, seeds only (optional)

This makes about 500 g of paste — ten 50 g portions, enough for two or three recipes. Blanched hazelnuts give a clean, smooth paste; skin-on nuts work if you rub off as much of the skin as possible after toasting, as the skins can taste bitter. For a classic French blend, replace a third of the hazelnuts with blanched almonds. Use a powerful food processor; small or weak machines can overheat. A sugar thermometer helps but is not essential: you can judge by colour.

iv. Method

1. Heat the oven to 160 °C (320 °F), fan 140 °C. Spread the hazelnuts on a tray and toast for 12–15 minutes, until golden right through when one is cut in half. Keep them warm.
2. Line a tray with baking paper or a silicone mat. In a wide, heavy pan, heat the sugar and water until the sugar dissolves, then boil without stirring until it reaches 118 °C, about 4–5 minutes.
3. Tip in the warm hazelnuts and stir continuously with a wooden spoon. The syrup will crystallise into a sandy white coating around the nuts within a minute or two.
4. Keep stirring over a medium heat. The sugar will slowly melt again and caramelise around the nuts. Continue until the nuts are coated in a glossy, deep amber caramel, about 8–10 minutes; lower the heat if any parts darken too fast.
5. Immediately tip onto the lined tray, spread out and sprinkle with the salt. Leave to cool completely and harden, about 30 minutes.
6. Break the praline into pieces and put it in a food processor with the vanilla seeds. Process, scraping down the sides regularly, through powder, then a clumped ball, then a thick paste, until it becomes smooth, glossy and runny — 8–15 minutes. Rest the motor for a minute if it becomes hot.
7. Pour into a clean jar and seal.

v. Tips & common mistakes

• Toast the nuts right through. The flavour of the praline depends on it. Cut one in half: it should be golden at the centre.
• Add the nuts warm. Cold nuts cool the syrup and slow caramelisation, giving an uneven coating.
• Keep stirring through the sandy stage. It looks wrong but it is right; the sugar will re-melt into caramel.
• Judge the caramel by colour and smell. Stop at deep amber. If it smells acrid, it has gone too far.
• Be patient with the processor. It always looks like dry powder first. Keep going and scraping down; the oil will come.
• Handle hot caramel with care. Molten sugar causes serious burns. Use a long spoon and keep children well away.

vi. Variations

Almond and hazelnut praliné, half and half, is the classic French blend. Pistachio, pecan, peanut and cashew pralines are all made the same way. Stop grinding early for a praliné à l'ancienne, a coarser, slightly crunchy paste. For pralin, simply crush the cooled caramelised nuts with a rolling pin and use them as a crunchy topping. Blend 100 g of the finished paste with 30 g melted chocolate and 40 g feuilletine for the crunchy base layer used in the chocolate hazelnut tart.

Use the praline in the Paris-Brest, the hazelnut mousse or as a buttercream for the dacquoise. For the other kind of praline, see Lyon's pink praline tart, and for brittle nut candies from elsewhere, the Indian chikki and sesame brittle.

vii. Serving & storage

Hazelnut praline is an ingredient rather than a dessert in itself, but it is also delicious spread on toast or brioche, swirled through yoghurt or ice cream, drizzled over crêpes or eaten from the spoon. Use it to flavour buttercream (beat 100 g into 250 g buttercream), whipped cream, ganache and pastry cream.

Store the praline in a sealed jar in a cool, dark cupboard for up to a month, or in the fridge for up to 2 months. The oil may separate and rise to the top; simply stir it back in. Refrigerated praline thickens, so bring it to room temperature before using. The crushed, unground praline brittle keeps for 2 weeks in an airtight tin.

ix. More from French

• Paris-Brest — praline cream choux ring
• Hazelnut Mousse — praline mousse
• Chocolate Hazelnut Tart — praline crunch and ganache
• Praline Tart — Lyon's pink tart
• Dacquoise — nut meringue layer cake
• Sesame Brittle — caramelised seed candy