STAGES OF COOKING: LOW-SUGAR JAM
Left: Initial Heating: The jam mixture (in this case, Early Girl Tomato & Damson Jam; page 280) heats up slowly, dissolving sugar. The mixture is stirred periodically and the heat is gradually increased to high as the sugar dissolves. Above left: Initial Bubbling and Foaming: Once hot, the mixture starts to foam. The tomato jam shown here rises moderately high in the pan; for foamier jams, such as apricot or plum, turning off the heat and skimming the foam partway through cooking helps prevent overflowing. Above right: Final Bubbling and Final Phase: As the volume and moisture content of the mixture decrease, the foam subsides. Stirring the mixture very frequently and reducing the heat slightly help prevent burning. The jam acquires a glossier look, the texture becomes more unified, and the color darkens. For testing for doneness, please see pages 36-37.