To make the basic apple juice stock, put the prepared apples and water in a stainless-steel or enamel preserving pan. Simmer for 45 minutes, or until soft and pulpy. Add the vinegar and cook for a further 5 minutes.
Meanwhile, prepare a jelly bag and stand. Alternatively, you can line two large nylon sieves or colanders with several layers of scalded muslin or scalded tea towels and place them over two large bowls.
Pour the apples and all the liquid into the jelly bag or lined sieves and allow to drain for 2–3 hours, or overnight.