Simmer for about 1.5 hours before turning out on to a large dish.

Reduce the heat, and just barely simmer for about 2 hours or until the stock is well flavored.

Simmer for 2 hours, adding more water if needed.

Bring to a boil, lower the heat slightly and simmer for 1 1/2 hours.

Simmer for 2 hours, adding more water as necessary.

Reduce to a simmer, and let simmer for 1-2 hours.

Simmer for 2 more hours until reduced by half.

Simmer for 24 hours, remove - and think you're enjoying!

These are barely covered with water or stock and simmered for three hours.

Cover the pan with a lid and leave to simmer for 3-4 hours.