Prepare mixed spice: Combine cinnamon, cloves, ginger, nutmeg, and allspice in a bowl. Reserve 1 heaped teaspoon for the mincemeat. Store the rest in a small jar for a later use.
Immerse two clean, 12-ounce jars in simmering water until mincemeat is ready. Wash new, unused lids and rings in warm soapy water.
Prepare mincemeat: Combine apple, sultanas, sugar, currants, raisins, and butter in a saucepan. Cook over low heat and stir gently until butter has melted. Stir in chopped almonds, orange zest, 1 teaspoon mixed spice, and cinnamon. Bring mixture to a simmer and cook, stirring occasionally, 5 to 10 minutes.
Remove from heat and set mincemeat aside to cool down for 30 minutes. Stir in brandy. Spoon into sterilized jars.