**Note before starting. For this recipe to be successful, it is crucial for working surfaces, tools and hands to be disinfected with ethanol.

Living microorganisms (Penicillium roqueforti and Penicillium candidum) are used, and their living conditions with regard to temperature, pH and available nutrients will largely determine how they grow, which is sometimes unpredictable. They will die if the temperature exceeds 35ºC, so they must be stored in the freezer.

INGREDIENTS (to serve 4)


4 apples

Lime solution:

1 litre water

20 gr quicklime

4 kg lactose (65%)

6 litres water

Penicillium roqueforti solution:

400 ml milk

1 gr starter

Penicillium candidum solution:

150 ml milk

3 gr starter


Apples cooked in lime solution


15 oranges

Sugar, 60% of the weight of the oranges

6 gr cardamom

6 gr pink pepper

2 gr star anise

10 gr juniper berries

1 gr cloves

To finish:

4 fermented apples

40 gr marmalade 


Apples: Peel, and shape slightly if necessary. Prepare a quicklime solution by dissolving the lime in the water. Submerge the apples and leave for 3 hours. Remove from the solution and rinse in cold water.

Prepare a syrup with the water and lactose. Cook the apples in the syrup for 30 to 40 minutes over a gentle heat so that they do not burst, until soft inside. Remove from the heat and leave to cool in the syrup. They must not be overcooked or they will lose their shape. Make a hole at the base of the apples and remove the flesh, leaving only the skin formed by the lime. Set aside.

Penicillium roqueforti solution: Dissolve the penicillium in the milk.

Penicillium candidum solution: Dissolve the penicillium in the milk.

Inoculation: Submerge the apples in the penicillium roqueforti solution and transfer to a pan together with two napkins to soak up any surplus liquid.

Brush the apples with the penicillium candidum solution, using a disinfected brush. Transfer to a new pan with a clean napkin.

Leave to ferment for 3 days or approximately 72 hours at room temperature (23-30ºC) or in a hot closet, until they turn blue and white.

Marmalade: Peel the oranges down to the flesh. Lightly press the segments to squeeze out some of the juice. Transfer to a pan and add 60% of their weight in sugar plus the spices. Cook over a high heat until the liquid evaporates, then cook slowly until the sugar caramelises a little and the texture of jam is obtained. Blend to make a thin marmalade.


Fill the fermented apples with the marmalade, taking care to not leave any traces on the fungus.