To prepare the jars
Thoroughly wash the jars, rinse in hot water. Place the jars and lids in a pan of hot water (approx. 70 °C.
Mix the water and lemon juice in a bowl. Peel and core the pears, place immediately in the lemon water.
Bring the water to the boil along with all the other ingredients up to and including the vanilla, add the pears, cook until just soft, fill the jars. Return the sugar syrup to the boil, pour the liquid into the jars until it covers the pears, seal the jars immediately.