Pressure cooker method - Pack the fruit into warm bottles and cover with boiling syrup to within 1 cm of the top. Put on the tops, leaving the screw caps slightly loose. Pour about 2.5 cm of boiling water into the pressure cooker and add a little vinegar to prevent staining. Set the bottles on the false bottom and separate them with cloth or newspaper. Fasten the lid and heat gently with the vent open until steam jets out in a steady stream. Close the vent and bring up the pressure to 0.35 kg/cm2 (low). The time that it takes from the start of heating until pressure is reached should not be less than 5 minutes, nor more than 10 minutes. For apples, rhubarb, all soft fruit, cherries, damsons, green gages and plums, hold the pressure for 1 minute. Extend this to 3–4 minutes in the case of apples if these are tightly packed, and also for halved apricots and whole or halved plums. Figs, pears and whole tomatoes need 5 minutes; solid-packed tomatoes, 15 minutes. Remove the pressure cooker from the heat, then leave it to stand for 10 minutes before opening the vent. The sterilising process is still going on during this time. Use tongs to carefully lift the bottles out onto a dry wooden surface. Tighten the screw caps.
Testing the seal
Allow the bottles to cool down completely, preferably leaving them overnight. Remove the screw caps or spring clips and test each bottle. To do this pick it up with your fingertips, holding it by the lid only. If the seal works, the vacuum that has been created inside the bottle will hold the lid securely. However, if the seal is faulty, the lid will come away.
Storing bottled fruit
Wipe off any sticky marks and label the bottles to show the type of fruit, the date of bottling and the covering liquid used. Store in a cool, dry, dark and well-ventilated place. To open bottled fruit, stand the jar in hot water for a few minutes and then gently prise off the lid using the tip of a knife.