Slightly carve the chestnuts on their front side and place them next to each other on a baking tray.
Roast in the oven at 175 °C for 10 minutes until the shell cracks slightly. Remove them from the stove and remove the skin, i.e. the outer brown skin and the inner fine skin.
Layer the chestnuts in jars. Caramelize the sugar in a suitable saucepan until brown. Extinguish with water, add the celery and make until the sugar is dissolved. Add the boiling sugar water without the celery to the fruit form and close the jars tightly.
Pasteurize in a water bath at 95 °C for about 25 min.
can also add a vanilla pod, which gives the chestnuts a wonderful aroma.