We had to juice a lot of lemons and limes while testing the recipes for the June/July 2010 issue, including the one for tabbouleh (see ** Tabbouleh**). That recipe calls for plenty of fresh lemon juice; unfortunately, the only lemons in our kitchen had been sitting in the fridge for days. I knew that a cold lime or lemon doesn't yield juice as readily as a room-temperature one, because cold makes the fruit's cell membranes more rigid. After breaking a sweat getting juice out of a few of those chilled lemons, I had an idea. I popped one into the microwave for 10 or 12 seconds. Bingo: the zapped lemon gave up its juice much more easily than a cold one.