Pick Meyer lemons when they no longer have any green, are entirely yellow and begin to deepen in color. As a hybrid between lemon and tangerine, ripe Meyer lemons are darker yellow than regular lemons.
The Meyer lemon variety is ever bearing, with its largest production from fall through winter. They have higher sugar content, less acid and a much thinner skin than true lemons. Because they lack the bitter pith of true lemons, there is no need to peel them for most recipes. For example, a recipe for lemon bars on NPR.org uses a chopped up deseeded Meyer lemon, peel and all, to make the filling.