IWIt is better to use two pans rather thanoverfill one, or use half quantities.3. What to useUse firm fruit or vegetables and washwell before using.4. Types of sugarPreserving sugar gives clear jam,however granulated sugar is cheaperand gives equally good flavour.5. CrystallizationCrystallization may be caused if sugaris not completely dissolved beforebringing the jam to the boil. Overboiling will affect the flavour, settingproperties and colour of the jam.6. To test jam for setting.If a jam thermometer is available, boilthe jam to 140˚C. Marmalade should beboiled to 106˚C.If no thermometer is available, removethe pan from the heat, place a sample ofjam on a cold dish and cool quickly (i.e.in a freezer or frozen food compartmentof a refrigerator). When cold, and if it isready, it should crinkle and hold themark of a finger run through it.7.The scum should be removed as soon aspossible after setting, but marmaladeshould be allowed to cool beforedecanting into jars to prevent the peelrising.