Queen Elizabeth reveals the secret ingredient for her royal Christmas pudding

The royals have shared their secret recipe for the Queen's Christmas pudding - but one ingredient may surprise you.

Palace chefs shared a video to the royal family's official Instagram page demonstrating how to make the Queen's boozy pudding, which contains dark rum, brandy and, surprisingly, beer.

"Today is Stir-up Sunday: traditionally the day when home cooks 'stir up' their Christmas pudding mixture on the Sunday before the Advent season - and the countdown to Christmas - begins," the caption reads.

Beer was traditionally used in the UK in Christmas pudding, which developed from a porridge dish called frumenty, writes the Daily Mail.

In the late 16th century, frumenty evolved into plum pudding with added dried fruits, eggs, breadcrumbs, and spirits and beer for flavour.

UK chef Richard Corrigan said the addition of beer was surprising - and had some other tips to make the perfect Christmas pud.

"Up the booze by 20 per cent. Add 200g of grated carrots, yes you heard me, it's brilliant, and 250g of prunes," he said.

Head chef at London restaurant 12:51 James Cochran said the use of beer was "intriguing".

"So unexpected in a royal pudding! But that leads me to think that they would enjoy my own personal take on a classic with inspiration from St Vincent in the Caribbean.

"Mine uses tropical dried fruit of pineapple, coconut, mango and sultanas and I like to feed the fruit with a caramelly based rum like Merser rum. I think with her penchant for the Caribbean, Princess Margaret would have loved this version."

Last year the royals shared snaps of the Queen, Charles, William and George whipping up a Christmas pudding together.

And royal fans were very enthusiastic to try out the recipe for themselves.

"That's cool that you're lending out your precious recipe to everyone. What a lovely Christmas gift to all, thank you," one commented on Instagram.

How to make the Royal Family's Christmas pudding

This recipe makes two 1kg puddings.

Ingredients

• 250g raisins
• 250g currants
• 185g sultanas
• 150g mixed peel
• 250g suet or vegetarian suet
• 250g breadcrumbs
• 90g flour
• 12g mixed spice
• 2 whole eggs
• 180g demerara sugar
• 275ml beer
• 40ml dark rum
• 40ml brandy
• If you don't want to use alcohol, you can substitute for orange juice or cold tea.

Method

1. Combine all dry ingredients and stir.
2. Add the eggs and liquid ingredients and stir it all up.
3. Grease your pudding basins, press the base mix into the basins and cover with a circle of baking paper.
4. Cover basins with a muslin cloth or foil and place puddings deep in a saucepan. Fill the saucepan with water to 3/4 of the pudding basin height.
5. Cover with foil and steam for six hours, refilling with water if needed.
6. Once cool, wrap the puddings well and keep them in a cool, dry place until Christmas.
7. On Christmas Day, reheat your pudding in a bain-marie for 3-4 hours. Remove from the basin using a rounded knife or palette knife, flip out onto a plate, garnish or flambé and serve with brandy sauce and cream.

This article was first published on the NZ Herald and republished here with permission.