Depending on the type of apple used, apple jelly can look yellowish, greenish or reddish, since the apples are cooked with the skin on. Remove stems and flowers. Apples with skin and core housing quarter and fill into a pot. Add water. Put a lid on it. Bring to the boil. Switch temperature to medium level. Simmer for 15 minutes until the top apples disintegrate. Do not stir, otherwise the apple jelly will become cloudy. Line a sieve with a cloth. Put it on a bowl. Pour the apples into the cloth. Drain very well. Do not express, otherwise the jelly will become cloudy. Pour the juice into the pot. Cook without lid for 10 minutes until bubbly. Stir in the gelling sugar. Cook for 4 minutes. If you eat 20 g of apple jelly per serving, that's about 40 kcal.