There are many different ways of making crab apple or cooking apple cheese. The simplest requires only the whole apples, roughly chopped with enough cold water to cover the bottom of the pan to stop them catching. Once cooked until meltingly soft, the mixture is pushed through a sieve and measured. For every 100ml of puree, you should allow 70g granulated sugar. It is then placed in a clean pan, set over a low heat and stirred until the sugar has dissolved. At this stage you can increase the heat to high and keep stirring until the mixture holds a trail. Then tip into a clean container.
Alternatively, you can make a spiced version as here, from my book
850ml dry cider
4 strips finely pared lemon rind
1 small stick cinnamon
1.4kg crab apples or cooking apples
1 Place the cider, lemon peel, cloves and cinnamon in a non-corrosive saucepan. Boil vigorously until the cider has reduced by one third. Wash the apples and roughly chop, pips, skin and all. Mix into the cider and simmer for about 90 minutes or until he apples are reduced to a pap. The smaller the quantity of apples, the quicker the cooking time.
2 Wash your containers in soapy water, rinse in piping hot water and dry. Lightly oil with sunflower oil. This enables you to turn out the apple cheese easily.
3 Push the mushy apples with their juice through a fine sieve. Measure out the puree and allow 70g sugar for every 100ml of puree. Place the sugar and apple pulp in a wide heavy-bottomed saucepan over a low heat. Stir until the sugar has dissolved, then bring to the boil and continue to cook, stirring all the time, until he mixture is so thick that spoon leaves a lean line when drawn across the bottom of the pan. This process will take about 25 minutes and as the puree thickens it will turn a beautiful dark amber if the apples are green, and deep pink if the apples are pink as here. It will also spit ferociously, so keep your arms well covered.
Pour the hot apple cheese into your containers and leave until cold before covering.