Bottling without Sugar FOOD FACTS ... and, if you follow these directions, it will be bottling without tears or fears. Our home-grown crop of fruit is precious. Every ounce of OVEN METHOD 1. Wash and drain jars. 2. Pack fruit tightly, almost to top of jar. 3. Place in moderate oven (250° F.) on cardboard or several thicknesses of paper. Jars should be covered with the lids (without rubber rings) to prevent fruit from burning. 4. Leave in oven for 3/4 hr. to 1 hr., until fruit is cooked. Fruit shrinks in cooking, so top up with fruit from one of the jars.