You can process any amount of fruit you'd like, however, I recommend not processing more than 4 pounds at a time (things get a bit tricky with a larger amount of fruit and the jam sometimes has a hard time gelling). Simply keep a ratio of one part fruit to one-half part sugar, keep the other ingredients the same. So if you came across three pounds of peaches, remove the pit and dice them. Then, weigh your fruit and use half of its weight in sugar.