Using a food processor is the fastest way to knead bread dough—rarely does it take longer than 1½ minutes, but it doesn’t work well if you’re working with very wet dough because it’s too hard on the motor. If you hear the motor straining at any time while you’re kneading the dough, turn the food processor off for 5 minutes before trying again. It may be necessary to finish kneading the dough by hand.
The food processor works at such high speeds that the friction it generates heats up the dough considerably. You can keep the temperature down by using ice water, but if you use ice water or even cold water it will kill dry yeast if you put the yeast in at the same time as the water. If you’re adding starter, however, any water you add should be very cold. If you notice the dough getting very warm, stick the whole food processor work bowl with the dough in it in the freezer for 15 minutes. You can also proof the yeast separately and add it after about 1 minute of processing, after the dough has warmed in the food processor.